Ion beam irradiation device

The present is a National Phase entry of PCT Application No. PCT/JP2013/053367, filed Feb. 13, 2013, which claims priority from Japanese Patent Application No. 2012-029716, filed Feb. 14, 2012, the disclosures of which are hereby incorporated by reference herein in their entirety.

The present invention relates to an ion beam irradiation device that irradiates a variety of substrates, for example, a substrate that forms a large flat panel display (FPD) with ion beams.

A large FPD, such as an organic EL display or a liquid crystal panel display, is manufactured through a process for irradiating, with ion beams, a substrate that forms a large FPD. Patent document 1 describes a known example of such a device that performs an irradiation process with ion beams. The device includes a plurality of ion sources and only transports a substrate in a transporting direction so that ion beam irradiation may be performed a number of times. In comparison with a structure that performs ion beam irradiation with a single ion source, this structure allows for versatility in the irradiation characteristics such as the dose and energy of ion beams that irradiates a substrate.

Patent Document 1: Japanese Laid-Open Patent Publication No. 2011-129332

However, in the ion beam irradiation device described above, due to the enlargement of substrates, the time during which a substrate is irradiated with ion beams often exceeds the time during which the output from an ion source can be maintained. Under such a condition, the output from the ion source may decrease or stop when irradiating a substrate with ion beams. Consequently, the ion beam irradiation amount varies over the plane of the substrate. In this regard, the structure described in patent document 1 allows for measures such as an increase in the number of times a substrate is transported, adjustment of the output from each ion source, or the application of both of these measures. This compensates for the insufficient irradiation amount, that is, this allows for the irradiation amount to be uniform throughout the plane of the substrate.

In a device such as the device described above, generally, a substrate is transported by rotating transport rollers arranged on a transport route, that is, by producing rotation with a motor to rotate the transport rollers. When transporting a substrate in such a manner, to perform repetitive ion beam irradiation when the output from the ion source decreases or stops, there is a need to accurately detect the position irradiated with ion beams for each irradiation so that the irradiation amount becomes uniform throughout the plane. However, in the transport system described above, a transport tray, which supports the substrate, often slips relative to a transport mechanism. Thus, when the substrate position is simply detected from a rotation position of the motor, the detection results of the substrate position may vary.

Unless such detection errors may be reduced, variations in the irradiation amount over the substrate plane cannot be resolved even when any of the measure described above is implemented. Thus, in an ion beam irradiation device, there is a need to detect the ion beam irradiation position on a substrate with higher accuracy.

Accordingly, it is an object of the present invention to provide an ion beam irradiation device that increases the accuracy for detecting an ion beam irradiation position on a substrate.

The means for solving the problem and the advantages of operations will now be described.

In the first aspect of the present invention, an ion beam irradiation device includes a vacuum chamber that accommodates a transport tray which holds a substrate, a transport unit that transports the transport tray in the vacuum chamber in a transport direction, an ion beam irradiation unit that irradiates, with ion beams, a predetermined irradiation position in the vacuum chamber, and a position detector that detects a position of the transport tray. The transport tray includes a plurality of indices that are arranged in the transport direction to indicate portions of the transport tray, and the position detector images each of the indices at a predetermined imaging position during transportation of the transport tray and detects a position of the transport tray relative to the imaging position based on the imaged index.

In the first aspect of the present invention, by imaging each of the indices, each of which indicates the corresponding position of the transport tray, the position of the transport tray relative to the imaging position is detected. The relative relation between the imaging position, where the index is imaged, and the irradiation position, to which ion beams are emitted, is continuously maintained in a predetermined relationship during transportation of the transport tray. Therefore, whenever the position detector detects the index of the transport tray, the position of the transport tray relative to the imaging position, that is, the position of the transport tray relative to the irradiation position is detected. This allows for the position of the transport tray relative to the irradiation position to be directly detected in comparison with when the position of the transport tray is detected from the operation amount of a transport mechanism, which transports the transport tray, or the like. Thus, even when there are differences between the transport mechanism, which transports the transport tray, and the transport tray, errors resulting from such differences would be limited. This increases the accuracy for detecting an irradiation position of the substrate, which is supported by the transport tray.

In the second aspect of the present invention, the ion beam irradiation device includes an output detector that detects an output of ion beams, an acquisition unit that acquires a detection result of the position detector and a detection result of the output detector in a predetermined cycle, and a memory unit that stores the detection result of the position detector and the detection result of the output detector that are obtained by the acquisition unit and associated with each other.

In the second aspect of the present invention, the detection result of the position detector and the detection result of the output detector are associated with each other and stored in the memory. This allows for recognition of the portion of the substrate irradiated with the desirable output of ion beams from information stored in the memory. In other words, the portion of the substrate that is irradiated with an undesirable output of ion beams and the portion of substrate that is not irradiated with ion beams may be recognized. This increases the accuracy of a process performed on a portion of the substrate where the irradiation of ion beams is insufficient to compensate for the insufficient irradiation.

In the third aspect of the present invention, the output detector detects when the output of ion beams stops.

In the third aspect of the present invention, among the irradiation positions of the substrate, the position where the output stops may be recognized. This increases the detection accuracy of the position where the output of ion beams stopped. Therefore, a further irradiation process may be performed with high accuracy on a portion of the substrate that was not irradiated with ion beams.

In the fourth aspect of the present invention, the transport unit transports the transport tray between a starting position of a transport process and a terminal position of the transport process, and the ion beam irradiation device includes a controller that controls transportation of the transport unit. The memory unit stores, as a stop position, the detection result of the position detector that is associated with the stop of the output of ion beams. When the output detector detects the stop of the output of ion beams, the controller drives the transport unit so that the transport tray moves back and forth between the starting position and the terminal position, and the ion beam irradiation unit outputs ion beams, based on the stop position and the detection result of the position detector, to a portion of the substrate that has not been irradiated with ion beams.

As described above, due to the enlargement of substrates, which are subjects of ion beam irradiation, an output of ion beams often stops when the substrate is traversing the irradiation position of ion beams.

In the fourth aspect of the present invention, when detecting that the output of ion beams has been stopped, the position of the transport tray relative to the imaging position is stored in the memory as the stop position associated with the stop of the output. When the position of the transport tray relative to the imaging position is between the stop position and the terminal position, ion beams are output again. Therefore, further irradiation of a portion that has not been irradiated with ion beams may be performed with high accuracy.

In the fifth aspect of the present invention, when the output detector detects the stop of the output of ion beams, the controller transports the transport tray in the transport direction until the position of the transport tray relative to the imaging position reaches a non-irradiation position where the substrate is not irradiated with ion beams and then transports the transport tray, from the non-irradiation position, in a direction opposite to the transport direction. The ion beam irradiation unit resumes ion beam irradiation when the position of the transport tray relative to the imaging position reaches the non-irradiation position, and stops the ion beam irradiation when the position of the transport tray relative to the imaging position reaches the stop position.

In general, an ion beam irradiation unit takes a longer time to adjust output of ion beams to a desirable predetermined value than to intentionally stop the output of ion beams.

In the fifth aspect of the present invention, when detecting that the output of ion beams has been stopped, the position of the transport tray relative to the image position is stored in the memory as the stop position associated with the stopping of the output. After the transport tray is transported to a non-irradiation position, the irradiation of ion beams is started again and the transportation of the transport tray is started in the direction opposite to that of the previous irradiation. When the position of the transport tray relative to the imaging position reaches the stop position, the irradiation of ion beams stops. Therefore, further irradiation of a portion of the substrate S that has not been irradiated with ion beams may be performed with high accuracy.

There are some modes for further irradiation of ion beams that are performed on a portion where the irradiation of ion beams is insufficient. In one mode, the substrate is scanned with ion beams as the transport tray is transported from the stop position in the transport direction. In another mode, the substrate is scanned with ion beams as the transport tray is transported to the stop position in a direction opposite to the transport direction. In the mode in which the transport tray is transported from the stop position in the transport direction, the output of ion beams needs to be resumed before the transport tray is positioned at the stop position. Consequently, at least some positions, which have been irradiated with ion beams, would again be irradiated with ion beams.

In the fifth aspect of the present invention, after the output is stopped, the ion beam irradiation is performed on the transport tray, which is transported in a direction opposite to the transport direction. Thus, the substrate is irradiated with ion beams, of which output is further stably maintained at the set value, compared with when the transport tray is transported from the stop position in the transport direction. This limits variations in the irradiation amount of the substrate from one end through the other end in the transport direction and allows for the irradiation amount to be uniform from one end through the other end of the substrate even when the output of ion beams stops before completion of the irradiation.

In the sixth aspect of the present invention, each of the indices is a barcode. The indices are arranged entirely from one end to the other end of the transport tray in the transport direction.

In the sixth aspect of the present invention, a plurality of barcodes are applied to the transport tray. More specifically, the barcodes are applied to the transport tray entirely from one end to the other end in the transport direction. This aspect allows for the position of the transport tray relative to the imaging position to be obtained entirely from one end to the other end of the transport tray T. Thus, regardless of where the transport tray T is located in the transport direction, the accuracy for detecting the position of the transport tray T may be increased.

In the seventh aspect of the present invention, the ion beam irradiation unit includes an ion source that outputs ion beams. The position detector and the ion source are located at opposite sides of the transport tray.

In the seventh aspect of the present invention, the position detector is located at the side of the transport tray opposite to the ion source. Thus, the indices, which are imaged by the position detector, are located at the same side of the transport tray as the position detector. In this aspect, the indices are located at the side of the transport tray that is not irradiated with ion beams. This limits deterioration in the outer appearance of each index caused by heat or the like of ion beams. Consequently, decreases are limited in the accuracy for detecting the irradiation position of ion beams that would be caused by the deteriorated outer appearance of each index.

In the eighth aspect of the present invention, the position detector is located at a position that does not face the irradiation position of the ion source.

In the eighth aspect of the present invention, the position detector is located at a position that does not face the irradiation position of the ion source. This limits heat deterioration of the imaging mechanism of the position detector. Consequently, decreases are limited in the accuracy for detecting the irradiation position of ion beams that would be caused by the deteriorated outer appearance of each index.

In the ninth aspect of the present invention, the irradiation position of the ion beam irradiation unit is divided, in an intersecting direction that intersects the transport direction, into a first irradiation position and a second irradiation position that contact each other. The ion beam irradiation unit includes a first ion source that irradiates the first irradiation position with ion beams and a second ion source that irradiates the second irradiation position with ion beams.

In the ninth aspect of the present invention, the irradiation position of the ion beam irradiation unit includes the first irradiation position and the second irradiation position. The first irradiation position and the second irradiation position are each irradiated by the different ion sources. Under this situation, the irradiation position is irradiated with ion beams by a plurality of the ion sources. Thus, the ion beam irradiation of the irradiation position may be performed in various manners as compared to when performed with a single ion source. This easily realizes the desirable irradiation amount on the irradiation region.

When the irradiation position of ion beams includes a first irradiation position and a second irradiation position, and if an overlap region in which portions of the irradiation positions are overlapped existed, the irradiation amount of ion beams to the overlap region would be a sum of the irradiation amount from the first ion source and the irradiation amount from the second ion source. Under this situation, when the irradiation position is to be irradiated with a predetermined amount of ion beams, each ion beam irradiation of the first ion source and the second ion source needs to be adjusted in consideration of the ion beam irradiation of the other ion source.

In contrast, in the ninth aspect of the present invention, the first irradiation position and the second irradiation position are located to contact each other. Therefore, there is no need to consider the overlap region described above when the ion beam irradiation of the first ion source and the second ion source is each adjusted. That is, adjustments may be made to the ion beam irradiation of each ion source. This simplifies the ion beam irradiation of the first ion source and the second ion source and improves the throughput of the ion beam irradiation process.

In the tenth aspect of the present invention, each of the indices is a barcode. The transport tray includes two barcode groups, each formed by a plurality of the barcodes. The two barcode groups are arranged so that the first irradiation position and the second irradiation position are located in between in the intersecting direction. The two barcode groups include a first barcode group located at a side of the first irradiation position and a second barcode group located at a side of the second irradiation position. The position detector includes a first position detector and a second position detector. The first position detector is arranged to image the first barcode group at a position facing the first barcode group. The second position detector is arranged to image the second barcode group at a position facing the second barcode group. The ion beam irradiation unit obtains the detection result from the second position detector during output from the first ion source. The ion beam irradiation unit obtains the detection result from the first position detector during output from the second ion source.

In the tenth aspect of the present invention, the transport tray includes the first barcode group and the second barcode group. More specifically, the first barcode group is applied to the first irradiation position side of the transport tray, and the second barcode group is applied to the second irradiation position side of the transport tray. When the first irradiation position is irradiated with ion beams, the second position detector images the first barcode group. When the second irradiation position is irradiated with ion beams, the first position detector images the second barcode group. Thus, ion beams output from the ion beam irradiation unit reach the substrate without being interfered by the position detector. That is, the position detector is not irradiated with ion beams output from the ion beam irradiation unit. Thus, the irradiation of the substrate with ion beams is not interfered. This increases the accuracy for detecting the irradiation position of ion beams.

FIG. 1A is a plan view showing the structure of one embodiment of an ion beam irradiation device, in which transport trays accommodated in the structure are indicated by solid lines, and FIG. 1B is a schematic side view showing the structure of the embodiment, in which the transport trays accommodated in the structure are indicated by dashed lines.

FIG. 2 is a diagram showing the internal structure of a processing chamber and a side structure of a transport tray.

FIG. 3A is an enlarged view showing some of upper barcodes, and FIG. 3B is a diagram of the information read from an upper barcode by a first barcode reader.

FIG. 4 is a block diagram showing the electrical configuration of an ion beam irradiation device.

FIG. 5 is a flowchart showing the procedures for performing an ion beam irradiation process.

FIG. 6 is a flowchart showing the procedures for performing a reverse transport process.

FIGS. 7A to 7F are operation diagrams sequentially showing the movement of transport trays in the ion beam irradiation process.

FIGS. 8A to 8E are operation diagrams sequentially showing the movement of transport trays in the ion beam irradiation process.

FIGS. 9A to 9F are operation diagrams sequentially showing the movement of transport trays in the reverse transport process.

FIGS. 10A to 10C are operation diagrams sequentially showing the movement of transport trays in the reverse transport process.

FIG. 11 is an enlarged view of some of upper barcodes in a modified example.

One embodiment of an ion beam irradiation device according to the present invention will now be described with reference to FIGS. 1 to 10 .

Entire Structure of Ion Beam Irradiation Device

First, the entire structure of the ion beam irradiation device will be described with reference to FIG. 1 .

As shown in FIG. 1A , the ion beam irradiation device 10 includes an attachment-removal chamber 11 , a load lock chamber 12 , a buffer chamber 13 , and a processing chamber 14 . Each of the chambers 11 to 14 is connected to an adjacent chamber through gate valves 15 .

The ion beam irradiation device 10 includes a outgoing line R 1 , which extends from the attachment-removal chamber 11 to the processing chamber 14 , and an incoming line R 2 , which extends from the processing chamber 14 to the attachment-removal chamber 11 . The lines are laid out parallel to each other. A plurality of transport trays T, which have the form of tetragonal plates, are transported along the outgoing line R 1 and the incoming line R 2 .

When a substrate S is received from the outer side, the attachment-removal chamber 11 attaches the substrate S to a transport tray T, which is in a lying position. When sending the transport tray T to the load lock chamber 12 , the attachment-removal chamber 11 arranges the transport tray T in an upright position. When the transport tray T is received from the load lock chamber 12 , the attachment-removal chamber 11 arranges the transport tray T in the lying position, removes the processed substrate S from the transport tray T, and sends the processed substrate S out of the attachment-removal chamber 11 . The attachment-removal chamber 11 attaches and removes the substrate S to and from the transport tray T and changes positions of the transport tray T under atmospheric pressure.

The transport tray T includes upper and lower frames, each of which is parallel to the transport line. When the transport tray T is in an upright position, a group C 1 of upper barcodes, each of which indicates a location on the upper frame, is applied to the upper frame, which holds the upper end of the substrate S. Also, a group C 2 of lower barcodes, each of which indicates a location on the lower frame, is attached to the lower frame, which holds the lower end of the substrate S. The barcode groups C 1 and C 2 are respectively applied to the upper frame and the lower frame entirely from one end to the other end in the transport direction. Each of the barcode groups C 1 and C 2 is, for example, a polyester tape or the like, on which the barcodes are printed (refer to FIG. 3A ).

The load lock chamber 12 receives the transport tray T from the attachment-removal chamber 11 along the outgoing line R 1 under atmospheric pressure and sends the transport tray T to the buffer chamber 13 along the incoming line R 1 under vacuum. Also, the load lock chamber 12 receives the transport tray T from the buffer chamber 13 along the incoming line R 2 under vacuum and sends the transport tray T to the attachment-removal chamber 11 along the incoming passage R 2 under atmospheric pressure.

The buffer chamber 13 , of which internal pressure is reduced to be equivalent to that of the load lock chamber 12 , receives the transport tray T from the load lock chamber 12 along the outgoing line R 1 and receives the transport tray T from the processing chamber 14 along the incoming line R 2 .

In the processing chamber 14 , the terminal end of the outgoing line R 1 includes two switch units TR arranged between the outgoing line R 1 and the incoming line R 2 . When the transport tray T is transported to the proximity of the terminal end of the outgoing line R 1 , the switch units TR move the transport tray T to the proximity of the starting end of the incoming line R 2 . In this manner, the switch units TR switch transport lines from the outgoing line R 1 to the incoming line R 2 .

The processing chamber 14 includes two side walls, each of which extends in the direction the chambers 11 to 14 are connected, that is, the transport direction. The side wall located at the side of the incoming line R 2 includes a first ion source 21 L, which irradiates the inner side of the processing chamber 14 with ion beams. Additionally, the portion of the side wall toward the starting end of the incoming line R 2 from the first ion source 21 L includes a second ion source 21 U, which irradiates the inner side of the processing chamber 14 with ion beams. The first ion source 21 L and the second ion source 21 U are spaced apart, for example, by a distance corresponding to the width of the transport tray T in the transport direction. The first ion source 21 L is arranged at a lower side of the side wall, and the second ion source 21 U is arranged at an upper side of the side wall.

Hereinafter, in the processing chamber 14 , the direction in which the transport tray T is transported in order of ion beam irradiation processing will be referred to as the forward direction. In contrast, the direction in which the transport tray T is transported opposite to the ion beam irradiation processing will be referred to as the reverse direction. That is, when the transport tray T is transported on the outgoing line R 1 , the transport tray T moves away from the buffer chamber 13 when transported in the forward direction. In contrast, when the transport tray T is transported on the incoming line R 2 , the transport tray T moves toward the buffer chamber 13 when transported in the forward direction. Thus, in each of the above situations, when transported in the opposite direction, the transport tray T is transported in the reverse direction. The white arrows in FIG. 1 indicate transportation in the forward direction.

The first ion source 21 L irradiates, with ion beams, a predetermined first irradiation position in the processing chamber 14 , which is a vacuum chamber. This irradiates, with ion beams, a lower region SL, which is the lower half, of the substrate arranged in the transport tray T when transported by the transport tray T. The second ion source 21 U irradiates, with ion beams, a predetermined second irradiation position in the processing chamber 14 . This irradiates, with ion beams, an upper region SU, which is the upper half, of the substrate S when transported by the transport tray T. Each ion source 21 L and 21 U irradiates, with ion beams, the substrate S set on the transport tray T transported on the outgoing line R 1 and the substrate S set on the transport tray T transported on the incoming line R 2 . More specifically, each of the ion sources 21 L and 21 U irradiates, twice with ion beams, the same substrate S, which is set on the same transport tray T, at different portions and different timings. Further, the ion sources 21 L and 21 U irradiate, with ion beams, the transport tray T that is being transported. Thus, portions of the substrate S irradiated with ion beams relatively move in the transport direction of the transport tray T.

As described above, the substrate S includes the upper region SU and the lower region SL, and each of the ion sources 21 L and 21 U irradiates each of the upper region SU and the lower region SL twice at different timings. Thus, the ion beam irradiation of the substrate S may be performed in various manners as compared to conditions in which the ion beam irradiation is performed on the substrate S from a single ion source or when the ion beam irradiation is performed on each region SU and SL only once. This easily realizes the desirable irradiation amount on the substrate surface. The regions SU and SL are arranged next to each other and irradiated with ion beams from different ion sources 21 L and 21 U. Thus, adjustments may be made to the ion beam irradiation of each ion source 21 L and 21 U. This simplifies ion beam irradiation from each ion source 21 L and 21 U as compared to a structure in which the regions of the ion beam irradiation overlap. This improves the throughput of the ion beam irradiation process.

To simplify the drawings, the ion sources 21 L and 21 U are shown at locations separated from the processing chamber 14 . Actually, each ion source 21 L and 21 U is arranged outside the processing chamber 14 and connected to the processing chamber 14 through a transmission passage, through which ion beams are transmitted.

The processing chamber 14 includes a first profile measurement unit 22 L, which measures the ion beam output from the first ion source 21 L, at a position opposing the first ion source 21 L. The outgoing line R 1 and the incoming line R 2 are arranged between the first profile measurement unit 22 L and the first ion source 21 L as viewed from above. Also, the processing chamber 14 includes a second profile measurement unit 22 U, which measures the ion beam output from the second ion source 21 U, at a position opposing the second ion source 21 U. The outgoing line R 1 and the incoming line R 2 are arranged between the second profile measurement unit 22 U and the second ion source 21 U as viewed from above. The first profile measurement unit 22 L and the second profile measurement unit 22 U measure the detected ion beam profiles, for example, the beam output distribution.

The processing chamber 14 includes a first barcode reader 23 A, which reads each of the barcodes in the upper barcode group C 1 and is arranged along the side wall, which extends in the direction the chambers 11 to 14 are connected, at the side of the outgoing line R 1 . The first barcode reader 23 A images a barcode at an imaging position where the first ion source 21 L and the first irradiation position of the first ion source 21 L are aligned along a straight line as viewed from above. When the transport tray T on the outgoing line R 1 reaches the first irradiation position, the first barcode reader 23 A detects one end of the upper barcode group C 1 at the imaging position. In this manner, the first barcode reader 23 A forms a second position detector, which images a barcode of the transport tray T on the outgoing line R 1 at a predetermined imaging position in the processing chamber 14 .

Also, the processing chamber 14 includes a second barcode reader 23 B, which reads each of the barcodes in the lower group C 2 and is arranged at the terminal end of the outgoing line R 1 from the first barcode reader 23 A along the above-mentioned side wall. The second barcode reader 23 B images a barcode at an imaging position where the second ion source 21 U and the second irradiation position of the second ion source 21 U are aligned along a straight line as viewed from above. When the transport tray T on the outgoing line R 1 reaches the second irradiation position, the second barcode reader 23 A detects one end of the lower barcode group C 2 at the imaging position. In this manner, the second barcode reader 23 B forms a first position detector, which images a barcode of the transport tray T on the outgoing line R 1 at a predetermined imaging position in the processing chamber 14 .

To simplify the drawings, each barcode reader 23 A and 23 B is shown at a location separated from the processing chamber 14 . Actually, the first barcode reader 23 A is arranged outside a top wall of the processing chamber 14 along the inner side of the side wall, and the second barcode reader 23 B is arranged outside a bottom wall of the processing chamber 14 along the inner side of the side wall.

Additionally, in the processing chamber 14 , a third barcode reader 23 C, which reads each of the barcodes in the lower barcode group C 2 , is arranged in a region between the outgoing line R 1 and the incoming line R 2 as viewed from above. The third barcode reader 23 C images a barcode at an imaging position where the second ion source 21 U and the second irradiation position of the second ion source 21 U are aligned along a straight line as viewed from above. When the transport tray T on the incoming line R 2 reaches the second irradiation position, the third barcode reader 23 C detects one end of the lower barcode group C 2 at the imaging position. In this manner, the third barcode reader 23 C includes a first position detector, which images a barcode of the transport tray T on the incoming line R 2 at a predetermined imaging position in the processing chamber 14 .

Additionally, in the processing chamber 14 , a fourth barcode reader 23 D, which reads each of the barcodes in upper barcode group C 1 , is arranged at the terminal end of the incoming line R 2 in a region between the outgoing line R 1 and the incoming line R 2 as viewed from above. The fourth barcode reader 23 D images a barcode at an imaging position where the first ion source 21 L and the first irradiation position of the first ion source 21 L are aligned along a straight line as viewed from above. When the transport tray T in the incoming line R 2 reaches the first irradiation position, the fourth barcode reader 23 D detects one end of the upper barcode group C 1 at the imaging position. In this manner, the fourth barcode reader 23 D includes a second position detector, which images a barcode of the transport tray T in the incoming line R 2 at a predetermined imaging position in the processing chamber 14 .

The third barcode reader 23 C, in the same manner as the second barcode reader 23 B, is arranged outside the bottom wall of the processing chamber 14 , and the fourth barcode reader 23 D, in the same manner as the first barcode reader 23 A, is arranged in outside the top wall of the processing chamber 14 .

In detail, as shown in FIG. 1B , among the two regions dividing the substrate S in the heightwise direction, which is perpendicular to the transport direction, the irradiation position of the first ion source 21 L entirely covers the lower region SL of the substrate S. The first profile measurement unit 22 L, which detects an ion beam, is arranged at a position facing the first irradiation position. In contrast, among the two regions, the second irradiation position of the second ion source 21 U entirely covers the upper region SU. The second profile measurement unit 22 U, which detects an ion beam, is arranged at a position facing the second irradiation position.

As described above, the transport tray T includes the barcode groups C 1 and C 2 , each of which includes a plurality of barcodes and continuously extends from the front end to the back end of the transport tray T in the transport direction, for example, the forward direction. Thus, a position, corresponding to the transport direction, of the transport tray T from one end to the other is obtained by each of the readers 23 A to 23 D. This allows for any position corresponding to an imaging position of the transport tray T, which is transported in the forward direction and the reverse direction, to be directly obtained. Thus, the accuracy for position detection of the transport tray T is increased.

The transport tray T includes the upper barcode group C 2 , which serves as the second barcode group arranged in the upper region SU of the substrate S, and the lower barcode group C 1 , which serves as the first barcode group arranged in the lower region SL of the substrate S. When the upper region SU is irradiated with ion beams, the second barcode reader 23 B and the third barcode reader 23 C, each of which serves as the first position detector, read the lower barcode group C 2 . In contrast, when the lower region SL is irradiated with ion beams, the first barcode reader 23 A and the fourth barcode reader 23 D, each of which serves as the second position detector, read the upper barcode group C 1 . Thus, ion beams, which are output from the ion sources 21 L and 21 U, reach the substrate S without being interfered by the barcode readers 23 A to 23 D. This controls output variations over the irradiation region of ion beams, which reach the substrate S. Also, the barcode readers 23 A to 23 D are not irradiated with ion beams. This limits deterioration of the barcode readers 23 A to 23 D caused by heat or the like of ion beams.

The processing chamber 14 , of which internal pressure is decreased to less than that of the buffer chamber 13 , receives the transport tray T along the outgoing line R 1 and irradiates the substrate S set on the transport tray T with ion beams. Also, the processing chamber 14 transports the transport tray T from the outgoing line R 1 to the incoming line R 2 . The processing chamber 14 irradiates the substrate S, which is set on the transport tray T, with ion beams and then sends the transport tray T to the buffer chamber 13 along the incoming line R 2 .

Detail Structure of Transport Tray

The structures related to the transport tray T and transportation of the transport tray T will now be described in detail with reference to FIG. 2 . As described above, the structure related to the transport tray T on the outgoing line R 1 is the same as that of the structure related to the transport tray T on the incoming line R 2 . Therefore, only the structure of the transport tray T on the outgoing line R 1 will be described below. FIG. 2 shows the internal structure of the processing chamber 14 and the structure of the transport tray T, which is transported on the outgoing line R 1 , as viewed from a side that is not irradiated with ion beams.

As shown in FIG. 2 , a tray frame 31 of the transport tray T is a tetragonal frame and includes an attachment slot 31 a , of which shape is approximately the same as that of the substrate S. The tray frame 31 includes an upper frame 31 b , which supports an upper edge of the substrate S, a lower frame 31 c , which supports a lower edge of the substrate S, and two side frames 31 d , each of which supports a side of the substrate S. The upper barcode group C 1 is applied to the entire upper frame 31 b in the transport direction. Also, the lower barcode group C 2 is applied to the entire lower frame 31 c in the transport direction. The upper barcode group C 1 and the lower barcode group C 2 are applied to the surface of the tray frame 31 that is not irradiated with ion beams. In this manner, each of the barcode groups C 1 and C 2 is not directly irradiated with ion beams. This limits deterioration of the barcodes caused by heat or the like of ion beams.

The substrate S, which is supported by the transport tray T, has, for example, a width W 1 of 2200 mm and a height H of 2400 mm. Each side frame 31 d has, for example, a width W 2 of 250 mm. Thus, each of the barcodes in the upper barcode group C 1 and the lower barcode group C 2 is an index indicating the location of the barcode on the frame from one end with a numerical value from 0 mm to 2700 mm. In other words, each barcode indicates an absolute position on the transport tray T in the transport direction. For example, a barcode that indicates 0 mm is applied to the front end of the transport tray T in the forward direction, and a barcode that indicates 2700 min is applied to the rear end of the transport tray T in the forward direction. When the transport tray T reaches the irradiation position of ion beams, the first barcode reader 23 A images the upper barcode group C 1 . Thus, a value, which is obtained by subtracting 250 mm, which is the width W 2 of the side frame 31 d , from the value indicated by the barcode, that is, the imaging position of the transport tray T, is the irradiation portion of the substrate S.

In this manner, the first barcode reader 23 A images the upper barcode group C 1 to unambiguously identify the irradiation position of ion beams on the substrate S. This limits differences between the actual irradiation portion on the substrate and the result of the position detector. Thus, the accuracy for detecting the irradiation position on the transport tray T is increased.

A tray magnet 32 is coupled to the upper end surface of the transport tray T. A cylindrical tray slider 33 is coupled to the lower end surface of the transport tray T.

A plurality of transport rollers 41 are arranged along the outgoing line R 1 on the bottom surface of the processing chamber 14 . The thickness of each transport roller 41 is approximately the same as that of the tray slider 33 . The circumferential surface of each transport roller 41 includes a groove to support the tray slider 33 . Each transport roller 41 is coupled to a transport roller motor that rotates the transport roller 41 . The transport roller 41 is rotated by the rotation produced with the corresponding transport roller motor. The transport roller motor is capable of generating rotation in the forward and reverse directions. When the transport roller motor switches the rotation directions, the rotation direction of the corresponding transport roller is switched accordingly.

In this manner, when the transport tray T is transported in the forward direction along the outgoing line R 1 , the transport rollers 41 rotate in the same direction. As a result, the tray slider 33 and the transport tray T are transported in the forward direction. To transport the transport tray T in the reverse direction along the outgoing line R 1 , the rotation of the transport rollers 41 is reversed. As a result, the transport tray T is transported in the reverse direction.

The upper wall of the processing chamber includes a plurality of support portions 42 , each of which includes a support magnet 42 M. The support portions 42 are arranged on the side opposite to where the transport rollers 41 are arranged. Each support magnet 42 M interacts with the tray magnet 32 when the tray magnet 32 reaches a position below the support magnet 42 M. In this manner, the transport tray T is remains held in the same position when transported along the outgoing line R 1 . When the transport tray T is transported along the outgoing line R 1 , for example, the transport tray T is kept tilted toward the opposite side of the ion sources 21 L and 21 U by a predetermined angle, for example, 3° from a vertical position relative to the bottom wall of the processing chamber 14 . Thus, when the ion beams irradiating the substrate S vibrates the substrate S, the substrate S cannot be easily removed from the transport tray T compared with when the transport tray T is transported held upright to be orthogonal to the bottom wall portion of the processing chamber 14 .

The structures related to transportation of the transport tray T along the outgoing line R 1 and the incoming line R 2 in the load lock chamber 12 and the buffer chamber 13 are the same as the processing chamber 14 except in that the support portions 42 are omitted.

Detail Structure of Barcode

The barcode groups C 1 and C 2 , each of which is applied to the transport tray T, will now be described with reference to FIG. 3 . Although the upper barcode group C 1 and the lower barcode group C 2 differ in the locations where they are applied, the structure of the tray frame 31 where the barcode groups C 1 and C 2 are applied are the same. Therefore, a portion of the upper barcode group C 1 will be described below. FIG. 3 shows the upper barcode group C 1 as viewed from the first barcode reader 23 A.

As shown in FIG. 3A , the upper barcode group C 1 includes a plurality of barcodes C 1 a . A numerical value C 1 b , which indicates a length of the upper frame 31 b from the front end in the forward direction, to the position where the barcode C 1 a is applied, is printed under each barcode C 1 a . Each barcode C 1 a is surrounded by a blank portion C 1 c.

Each of the first barcode reader 23 A and the fourth barcode reader 23 D, which reads the upper barcode group C 1 , includes an imaging unit that images the upper barcode group C 1 in a predetermined cycle and detects, from the image of the upper barcode group C 1 captured by the imaging unit, the position of the transport tray T relative to the imaging position.

When the image captured by the imaging unit includes “000183” as shown in FIG. 3A , that is, the barcode C 1 a indicating a position separated by 183 mm from one end of the upper frame 31 b , and portions of the adjacent barcodes, each of the barcode readers 23 A and 23 D converts the image to binary data as shown in FIG. 3B . Each of the barcode readers 23 A and 23 D decodes the binary data to detect the length from the front end of the upper frame 31 b in the forward direction to the imaging position, which is the position of the transport tray T relative to the imaging position, in the predetermined cycle. By detecting the length from the front end in the forward direction to the imaging position, the length from the front end in the reverse direction to the imaging position is detectable. That is, the length from one end in the transport direction, which includes the forward direction and the reverse direction, to an imaging position is detectable.

The second barcode reader 23 B and the third barcode reader 23 C, which read the lower barcode group C 2 , are located in the processing chamber 14 at positions that differ from the first barcode reader 23 A and the fourth barcode reader 23 D. Otherwise, the structures of second barcode reader 23 B and the third barcode reader 23 C are the same as the first barcode reader 23 A and the fourth barcode reader 23 D.

One known example of a so-called absolute type linear encoder, which detects the absolute position as described above, is an electromagnetic induction linear encoder. An electromagnetic induction linear encoder includes a scale, which is a tape marked with calibrations or the like, and a reader, which detects the calibrations while changing positions relative to the scale. The distance from the scale to the reader needs to be within approximately a few millimeters for the reader to be able to detect the calibrations.

If the transport tray T were to be transported held generally orthogonal to the bottom wall portion of the processing chamber 14 , the transport tray T may sway in a direction generally orthogonal to the transport direction. This varies the distance between the scale, which is coupled to the transport tray T, and the reader. As described above, the detectable range of the reader is approximately a few millimeters. Thus, when the transport tray T sways, the distance between the scale, which is coupled to the transport tray T, and the reader may exceed the detectable range of the reader. This would lower the reliability of the detected distance in the electromagnetic induction linear encoder.

Additionally, there is a need for the reader to be located in the processing chamber, which is in a vacuum condition. Thus, the amount of outgas needs to be within a certain amount and grains forming particles should not collect on the reader.

In this regards, each of the barcode readers 23 A to 23 D in the present embodiment is an optical linear encoder, which includes the imaging unit, and does not contact the barcode groups C 1 and C 2 , which serve as scales. This allows for each of the barcode readers 23 A to 24 D to detect the barcode C 1 a over a long distance as compared to the electromagnetic induction linear encoder. Thus, the barcode C 1 a is detectable even when the transport tray T sways as described above. As a result, in the barcode readers 23 A to 23 D and the barcode groups C 1 and C 2 of the present embodiment, the absolute position is detectable, and the reliability of the detected distance is increased.

Each of the barcode readers 23 A to 23 D is arranged outside the processing chamber 14 . As each of the barcode groups C 1 and C 2 moves, the position of each of the barcode groups C 1 and C 2 change relative to each of the barcode readers 23 A to 23 D. In this manner, the use of the barcode readers 23 A to 23 D eliminates the restrictions that would be imposed when using an electromagnetic induction linear encoder, and allows for the detection of the absolute position.

Electrical Configuration of Ion Beam Irradiation Device

The electrical configuration of the ion beam irradiation device 10 will now be described with reference to FIG. 4 . FIG. 4 shows the electrical configuration related to ion beam irradiation and transportation of the transport tray T in the processing chamber 14 . These configurations will be described below. The electrical configurations of structures other than the processing chamber 14 , for example, the structure related to the transportation of the transport tray T through the chambers 11 , 12 and 13 , and the structure related to the opening and closing of each gate valve 15 will not be described.

A main controller 50 , which is arranged in the ion beam irradiation device 10 , is mainly formed by a microcomputer, which includes a central processing unit (CPU), a nonvolatile memory (ROM), and a volatile memory (RAM). Based on various data and programs stored in the ROM and RAM, the main controller 50 performs various controls associated with operations of the ion beam irradiation device 10 .

A motor controller 60 , which is connected to the main controller 50 , controls the operations of various motors installed in the processing chamber 14 , especially motors for transporting the transport tray T. A drive circuit 61 D and an encoder 61 E are connected to the motor controller 60 . The drive circuit 61 D drives a transport roller motor 61 M, which is connected to a transport roller 41 , and generates rotation with the transport roller motor 61 M. The encoder 61 E detects a rotation position of the transport roller motor 61 M. The motor controller 60 generates a position instruction based on a drive instruction, which is received from the main controller 50 , and a rotation position, which is received from the encoder 61 E, and outputs the position instruction to the drive circuit 61 D.

Based on the position instruction, which is received from the motor controller 60 , the drive circuit 61 D generates drive current for the transport roller motor 61 M and outputs the drive current to the transport roller motor 61 M. The transport roller motor 61 M generates rotation corresponding to the received drive current to rotate the transport roller 41 . The drive circuit 61 D and the encoder 61 E are provided for each transport roller motor 61 M.

When the deviation between the rotation position, which is received from the encoder 61 E, and the position instruction becomes less than or equal to a predetermined value, the motor controller 60 generates a completion signal, which indicates that the operation of the transport roller motor 61 M based on the drive instruction has been completed, outputs the completion signal to the main controller 50 , and waits for a further drive instruction from the main controller 50 .

Additionally, a drive circuit 62 D and an encoder 62 E are connected to the motor controller 60 . The drive circuit 62 D generates rotation and drives a switch motor 62 M, which is included in each switch unit TR, to generate rotation with the switch motor 62 M. The encoder 62 E detects a rotation position of the switch motor 62 M. The motor controller 60 calculates a position instruction based on the drive instruction, which is received from the main controller 50 , and a rotation position, which is received from the encoder 62 E, and outputs the position instruction to the drive circuit 62 D.

Based on the position instruction, which is received from the motor controller 60 , the drive circuit 62 D generates drive current for the switch motor 62 M and outputs the drive current to the switch motor 62 M. The switch motor 62 M generates rotation corresponding to the received drive current to drive the switch unit TR. The drive circuit 62 D and the encoder 62 E are provided for each transport roller motors 61 M forming a switch unit TR.

When the deviation between the rotation position, which is received from the encoder 61 E, and the position instruction becomes less than or equal to a predetermined value, the motor controller 60 generates a completion signal, which indicates that the operation of the switch motor 62 M based on the drive instruction has been completed, outputs the completion signal to the main controller 50 , and waits for a further drive instruction from the main controller 50 . A transport unit includes the motor controller 60 , the drive circuit 61 D, the transport roller motor 61 , the transport roller 41 , and the encoder 61 E.

An ion beam controller 70 , which controls and drives the ion sources 21 L and 21 U, is connected to the main controller 50 . A drive circuit 71 D, which operates the first ion source 21 L to output ion beams, a first output sensor 71 S, which detects the output from the first ion source 21 L, and the first profile measurement unit 22 L are connected to the ion beam controller 70 .

Based on a drive instruction, which is received from the main controller 50 , and measurement data, which is received from the first profile measurement unit 22 L, the ion beam controller 70 generates an output instruction and outputs the output instruction to the drive circuit 71 D. The first profile measurement unit 22 L generates measurement data corresponding to the measured result such as the intensity distribution of ion beams and outputs the measurement data to the ion beam controller 70 .

Based on an output instruction, which is received from the ion beam controller 70 , the drive circuit 71 D generates drive current for the first ion source 21 L and outputs the drive current to the first ion source 21 L. The first ion source 21 L outputs ion beams corresponding to the received drive current.

When the operation of the first ion source 21 L is completed based on the drive instruction, the ion beam controller 70 generates a completion signal, outputs the completion signal to the main controller 50 , and waits for a further instruction from the main controller 50 .

The first output sensor 71 S is, for example, a sensor that detects the current flowing through a filament of the first ion source 21 L. When the detected current value is less than or equal to a predetermined value, the first output sensor 71 S generates an output stop signal, which indicates that the output of ion beams has stopped, and outputs the output stop signal to the ion beam controller 70 .

The first barcode reader 23 A and the fourth barcode reader 23 D, each of which reads the upper barcode group C 1 of the transport tray T, are connected to the ion beam controller 70 . The first barcode reader 23 A and the fourth barcode reader 23 D each detect the absolute position from the portion of the upper barcode group C 1 imaged at the imaging position, generates position data corresponding to the imaging position in a predetermined imaging cycle, and outputs the position data to the ion beam controller 70 . When the first output sensor 71 S outputs the output stop signal, the position data, which is generated in an imaging cycle in which the output stop signal is output, is stored in a memory 70 a of the ion beam controller 70 . In this manner, the position data, which is input to the ion beam controller 70 and corresponds to the result detected from the first output sensor 71 S, is stored in the memory 70 a.

A drive circuit 72 D, which operates the second ion source 21 U to output ion beams, a second output sensor 72 S, which detects the output from the second ion source 21 U, and the second profile measurement unit 22 U are connected to the ion beam controller 70 .

Based on a drive instruction, which is received from the main controller 50 , and measurement data, which is received from the second profile measurement unit 22 U, the ion beam controller 70 generates an output instruction and outputs the output instruction to the drive circuit 72 D. The second profile measurement unit 22 U generates measurement data, in the same manner as the first profile measurement unit 22 L, and outputs the measurement data to the ion beam controller 70 .

Based on an output instruction, which is received from the ion beam controller 70 , the drive circuit 72 D generates drive current for the second ion source 21 U and outputs the drive current to the second ion source 21 U. The second ion source 21 U outputs ion beams corresponding to the received drive current.

When the operation of the second ion source 21 U is completed based on the drive instruction, the ion beam controller 70 generates a completion signal, outputs the completion signal to the main controller 50 , and waits for a further instruction from the main controller 50 .

The second output sensor 72 S is, for example, a sensor that detects the current flowing through a filament. When the detected current value is less than or equal to a predetermined value, the second output sensor 72 S generates an output stop signal, which indicates that the output of ion beams has stopped, and outputs the output stop signal to the ion beam controller 70 .

The second barcode reader 23 B and the third barcode reader 23 C, each of which reads the lower barcode group C 2 of the transport tray T, are connected to the ion beam controller 70 . The second barcode reader 23 B and the third barcode reader 23 C each detect the absolute position from a portion of the lower barcode group C 2 imaged at the imaging position, generates position data in a predetermined imaging cycle, and outputs the position data to the ion beam controller 70 . When the second output sensor 72 S outputs the output stop signal, the position data, which is generated in an imaging cycle in which the output stop signal is output, is stored in a memory 70 a of the ion beam controller 70 . Thus, the position data, which is input to the ion beam controller 70 and corresponds to the result detected from the first output sensor 72 S, is stored in the memory 70 a.

In this manner, the barcode readers 23 A to 23 D, which detect the position of the transport tray T relative to the imaging position, are connected to the ion beam controller 70 , which controls and drives ion beams. Thus, data, which indicates whether or not the desired ion beams are output, and data, which is related to the position of the transport tray T corresponding to the imaging position, that is, a portion exposed to ion beams, are input to the same controller in the predetermined imaging cycle. In comparison with when such data is stored in different controllers, deviation is decreased between the position of the transport tray T relative to the imaging position when the output of ion beams is stopped, that is, a stop position, and the irradiation position of ion beams.

The ion beam controller 70 , the ion sources 21 L and 21 U, the drive circuits 71 D and 72 D, and the output sensors 71 S and 72 S form an ion beam irradiation unit. The output sensors 71 S and 72 S form an output detection unit. The ion beam controller 70 forms an acquisition unit.

Operation of Ion Beam Irradiation Device

Among the operations of the ion beam irradiation device 10 , the operation of ion beam irradiation that is performed in the processing chamber 14 will now be described with reference to FIGS. 5 to 10 . Prior to the ion beam irradiation process, which is described below, operations such as transportation of the transport tray T in the buffer chamber 13 , the opening and closing of each gate valve 15 , and transportation of the transport tray T from the buffer chamber 13 to the processing chamber 14 are performed in accordance with other processing flows. Abnormal stopping occurs when the ion sources 21 L and 21 U are irradiating the substrate S with ion beams may be when the ion beams are stopped in an unexpected manner, or when the sensors 71 S and 72 S output an output stop signal. Otherwise, normal irradiation is performed. In FIGS. 7 to 10 , the white arrows indicate the transportation of each of the transport trays T 1 and T 2 in the forward direction. In FIG. 9 , black arrows indicate the transportation of the transport tray T 1 in the reverse direction.

Normal Irradiation

When the ion beam irradiation process starts, the transport trays T remains still at predetermined stop positions in the processing chamber 14 . One or two transport trays T are accommodated in the processing chamber 14 (refer to FIG. 7A ). One example of an irradiation process in which the first ion source 21 L irradiates, with ion beams, an unprocessed substrate S, which is set on transport tray T 2 , will now be described. At the same time, the second ion source 21 U also irradiates, with ion beams, the substrate S, which is set on a preceding transport tray T 1 . The ion beam irradiation process is performed on the transport tray T 1 in accordance with another processing flow, which is the same as the ion beam irradiation process described below.

First, in the ion beam irradiation process, the main controller 50 generates a drive instruction for the ion beam controller 70 and outputs the drive instruction. Then, the ion beam controller 70 generates an output instruction based on the drive instruction and outputs the output instruction to the drive circuit 71 D. The drive circuit 71 D generates drive current based on the output instruction and outputs the drive current to the first ion source 21 L. Then, the first ion source 21 L starts the irradiation of lower ion beams BL (step S 101 ) (refer to FIG. 7B ).

When the irradiation of lower ion beams BL starts, the first profile measurement unit 22 L generates measurement data corresponding to the detected lower ion beams BL and outputs the measurement data to the ion beam controller 70 . If the lower ion beams BL are output with a predetermined profile corresponding to the output instruction (step S 102 : YES), the ion beam controller 70 generates a completion signal, which indicates that the output of ion beams has been adjusted, and outputs the completion signal to the main controller 50 .

In addition to the above completion signal, if the ion beam controller 70 outputs a completion signal indicating that the adjustment of upper ion beams BU output from the second ion source 21 U has been completed within a predetermined period (step S 103 : YES), the main controller 50 generates a drive instruction to transport the transport tray T in the forward direction and outputs the drive instruction to the motor controller 60 . The motor controller 60 generates a position instruction based on the received drive instruction and a rotation position received from the encoder 61 E and outputs the position instruction to the drive circuit 61 D. Then, the drive circuit 61 D generates drive current corresponding to the position instruction and outputs the drive current to the transport roller motor 61 M. This starts transportation of the transport tray T 2 (step S 104 ). At the same time, transportation of the transport tray T 1 in the forward direction starts in the same manner.

The driving of the transport roller motors 61 M starts from the one coupled to the transport roller 41 that is located at the starting end of the outgoing line R 1 . When the rotation generated by the transport roller motor 61 M reaches a predetermined rotation position, this starts the driving of the transport roller motor 61 M coupled to the adjacent transport roller 41 , which is located toward the terminal end in the outgoing line R 1 . The driving of each transport roller motor 61 M stops at a predetermined rotation position, for example, when the corresponding transport roller 41 no longer contacts the tray slider 33 . In this manner, the driving of the transport roller motors 61 M is sequentially performed from the starting end side of the outgoing line R 1 . This transports the transport tray T 2 from the starting end to the terminal end of the outgoing line R 1 , that is, in the forward direction.

During transportation of the transport tray T 2 , the imaging of the upper barcode group C 1 , that is, the detection of the position of the transport tray T 2 relative to the imaging position is started when the front end in the forward direction of the upper barcode group C 1 of the transport tray T 2 , for example, the barcode indicating that the length from the front end of the transport tray T is 0 mm, reaches an imaging position of the first barcode reader 23 A (step S 105 ) (refer FIG. 7C ).

When the first barcode reader 23 A starts imaging the upper barcode group C 1 , ion beam irradiation of the transport tray T 2 is also performed. When the first barcode reader 23 A detects a barcode indicating that the length from the front end of the transport tray T is 250 mm, the irradiation of the substrate S with the lower ion beams BL is started.

The irradiation of the lower ion beams from the first ion source 21 L is continued until the first barcode reader 23 A detects a barcode indicating that the length from the front end of the transport tray T is 2700 mm (step S 106 : YES, step S 107 : YES). Then, the ion beam controller 70 generates an output instruction to stop the output from the first ion source 21 L and outputs the output instruction to the drive circuit 71 D. The drive circuit 71 D generates drive current based on the received output instruction and outputs the drive current to the first ion source 21 L. When receiving the drive current, the first ion source 21 L stops outputting the lower ion beams BL (step S 108 ). Then, when receiving a signal indicating that the output current of the first ion source 21 L is 0 A from the first output sensor 71 S, the ion beam controller 70 generates a completion signal indicating that the irradiation of ion beams has been completed by the drive instruction, outputs the completion signal to the main controller 50 , and waits for a further drive instruction.

When the irradiation of the lower ion beams BL stops, the main controller 50 transports the transport tray T 2 by a predetermined distance in the forward direction. Then, the main controller 50 generates a drive instruction for stopping the transportation and outputs the instruction to the motor controller 60 . The predetermined distance is set so that, for example, the transport tray T 2 is positioned between the irradiation position of the first ion source 21 L and the irradiation position of the second ion source 21 U when moved by the predetermined distance.

The motor controller 60 generates a position instruction based on the drive instruction and a rotation position received from the encoder 61 E and outputs the position instruction to the drive circuit 61 D. Then, the drive circuit 61 D generates drive current based on the position instruction and outputs the drive current to the transport roller motor 61 M. The roller motor 61 M produces rotation corresponding to the drive current.

When the deviation between the rotation position, which is received from the encoder 61 E, and the position instruction becomes less than or equal to a predetermined value, the motor controller 60 generates a position instruction to stop rotation generated with the transport roller motor 61 M and outputs the position instruction to the drive circuit 61 D. The drive circuit 61 D generates drive current corresponding to the received position instruction and outputs the drive current to the transport roller motor 61 M. In this manner, the transport roller motor 61 M stops generating rotation. This ends transportation of the transport tray T 2 (step S 109 ).

When the transportation of the transport tray T 2 ends and a signal indicating that the output from the second ion source 21 U has stopped (step S 110 : NO), the main controller 50 generates a drive instruction to delay restarting the transportation of the transport tray T 2 in the forward direction for a predetermined period and outputs the drive instruction to the motor controller 60 . The motor controller 60 generates a position instruction based on the drive instruction and a rotation position received from the encoder 61 E and outputs the position instruction to the drive circuit 61 D. The drive circuit 61 D generates drive current corresponding to the position instruction and outputs the position instruction to the transport roller motor 61 M. The transport roller motor 61 M stops generating rotation at a predetermined position corresponding to the received drive current. Consequently, the transport tray T 2 waits at the terminal position of the transport process (step S 151 ). The time during which transportation is continuously stopped, that is, the waiting time, is the time until the reverse transport process is completed during abnormal stopping as described below. Under this situation, the main controller 50 temporarily ends the process of the ion beam irradiation.

In addition to the first irradiation of the lower ion beams BL, the transport tray T 2 sequentially undergoes the first irradiation of upper ion beams BU, the second irradiation of upper ion beams BU, and the second irradiation of lower ion beams BL before being transported out of the processing chamber 14 . The driven one of the ion source 21 L and 21 U and the driven one of the transport roller motors 61 M differs between each ion beam irradiation. However, each ion beam irradiation is performed using the same process, which is described above.

In detail, as shown in FIGS. 7D to 7F , when the first irradiation of upper ion beams BU is performed, the profile of the upper ion beams BU, which are output from the second ion source 21 U, is first measured. Then, the transport tray T 2 is transported toward the terminal end of the outgoing line R 1 in the forward direction, and the upper region SU of the substrate S is irradiated with upper ion beams BU. In the first irradiation of upper ion beams BU, when transported to the terminal end of the outgoing line R 1 , the transport tray T 2 is moved on the incoming line R 2 by the switch unit TR. This ends the transportation of the transport tray T 2 . Then, the unloading process of the transport tray T 1 , the loading process of a transport tray T 3 , and the opening-closing of the gate valves 15 are performed in accordance with other processing flows.

As shown in FIGS. 8A and 8B , when the second irradiation of upper ion beams BU is performed, the profile of the upper ion beams BU, which are output from the second ion source 21 U, is first measured. Then, the transport tray T 2 is transported toward the terminal end of the incoming line R 2 in the forward direction, and the upper region SU of the substrate S is irradiated with upper ion beams BU.

As shown in FIGS. 8C to 8E , when the second irradiation of lower ion beams BL is performed, the profile of the lower ion beams BL, which are output from the first ion source 21 L, is first measured. Then, the transport tray T 2 is transported toward the terminal end of the incoming line R 2 in the forward direction, and the lower region SL of the substrate S is irradiated with lower ion beams BL.

Abnormal Stopping

As described above, when the transport tray T 2 reaches the irradiation position of the first ion source 21 L, the irradiation of the substrate S set on the transport tray T 2 with lower ion beams BL is started (refer to FIG. 9A ). As the transport tray T 2 traverses the irradiation position of the first ion source 21 L, if the irradiation of lower ion beams BL stops (refer to FIG. 9B ), the first output sensor 71 S generates an output stop signal for the first ion source 21 L and outputs the signal to the ion beam controller 70 .

The ion beam controller 70 generates an abnormal stopping signal indicating that the output from the first ion source 21 L has abnormally stopped based on the received output stop signal and outputs an abnormal stopping signal to the main controller 50 (step S 106 : NO). Then, a reverse transport process is performed in the processing chamber (step S 141 ).

The reverse transport process, in which the transport tray T 2 is transported in the reverse direction, will now be described. In the description hereafter, it is assumed that the irradiation of the transport tray T 1 with upper ion beams has been normally performed.

When receiving the above output stop signal from the first output sensor 71 S, the ion beam controller 70 stores position data obtained in the imaging cycle, in which the signal has been received, as a stop position where the irradiation of lower ion beams BL stopped (step S 201 ).

Then, in the same manner as when the irradiation from the first ion source 21 L is normal, the main controller 50 generates a drive instruction to transport the transport tray T 2 to the terminal position of the transport process and outputs the drive instruction to the motor controller 60 . The motor controller 60 generates a position instruction based on the drive instruction and a rotation position received from the encoder 61 E. The motor controller 60 then outputs the position instruction to the drive circuit 61 D. The drive circuit 61 D generates drive current based on the position instruction. The drive circuit 61 D outputs the drive current to the transport roller motor 61 M. Then, the transport roller motor 61 M generates rotation corresponding to the drive current.

When the transport tray T 2 is transported to the terminal position of the transport process in the forward direction, the transportation of the transport tray T 2 is stopped (step S 202 ) (refer to FIG. 9C ). At this point, in the same manner as step S 151 described above, the main controller 50 generates a drive instruction to have the transport tray T 1 wait at the terminal position and outputs the drive instruction to the motor controller 60 .

The main controller 50 generates a drive instruction for the ion beam controller 70 , which instructs the first ion source 21 L to output lower ion beams BL, and outputs the drive instruction to the ion beam controller 70 . The ion beam controller 70 generates an output instruction based on the drive instruction and outputs the output instruction to the drive circuit 71 D. The drive circuit 71 D generates drive current corresponding to the output instruction and outputs the output instruction to the first ion source 21 L. The first ion source 21 L outputs lower ion beams BL corresponding to the drive current (step S 203 ) (refer to FIG. 9D ).

In the same manner as step S 102 described above and step S 121 , when lower ion beams BL are output, the profile of the lower ion beams BL is adjusted. Then, the ion beam controller 70 generates a completion signal indicating that the output adjustment has been completed. The ion beam controller 70 outputs the completion signal to the main controller 50 and waits for a further instruction (step S 204 : YES).

When receiving the completion signal, the main controller 50 generates a drive instruction to transport the transport tray T 2 in the reverse direction and outputs the drive instruction to the motor controller 60 . The motor controller 60 generates a position instruction based on the received drive instruction and a rotation position received from the encoder 61 E. The motor controller 60 then outputs the position instruction to the drive circuit 61 D. The drive circuit 61 D generates drive current based on the received position instruction and outputs the drive current to the transport roller motor 61 M. This transports the transport tray T 2 in the reverse direction along the outgoing line R 1 (step S 205 ) (refer to FIG. 9E ).

When the barcode indicating that the length from the front end of the transport tray T in the forward direction is 2700 mm reaches an imaging position of the first barcode reader 23 A, the imaging of the upper barcode group C 1 and the position detection of the transport tray T relative to the imaging position are performed (step S 206 ) in the same manner as step S 105 described above. In step S 105 , the first barcode reader 23 A images barcodes from the one indicating that the length from one end of the transport tray T is 0 mm toward the one indicating that the length from one end of the transport tray T is 2700 mm. In contrast, in step S 206 , the first barcode reader 23 A images barcodes from the one indicating that the length from one end of the transport tray T is 2700 mm toward the one indicating that the length from one end of the transport tray T is 0 mm.

During this period, the ion beam controller 70 compares the position of the transport tray T, which is detected by the first barcode reader 23 A, with the stop position, which is stored in the memory 70 a in step S 201 described above (step S 207 ) (refer to FIG. 9F ). If the stored stop position and the position of the transport tray T relative to the imaging position are the same, the ion beam controller 70 generates an output instruction to stop the output of ion beams from the first ion source 21 L and outputs the output instruction to the drive circuit 71 D. The drive circuit 71 D generates drive current based on the received output instruction and outputs the drive current to the first ion source 21 L. When receiving the drive current, the first ion source 21 L stops outputting ion beams (step S 208 ).

When the output of ion beams is stopped, a signal, which indicates that the output current from the first ion source 21 L is 0 A is input to the ion beam controller 70 . Then the ion beam controller 70 generates a completion signal, which indicates that the irradiation of ion beams has been completed, outputs the signal to the main controller 50 , and waits for a further drive instruction. When receiving the completion signal, the main controller 50 generates a drive instruction to transport the transport tray T by a predetermined distance in the reverse direction and then stop the transport tray T. The main controller 50 outputs the drive instruction to the motor controller 60 . The predetermined distance is set so that the transport tray T 2 is located closer to the gate valves 15 than the irradiation position of the first ion source 21 L when moved by the predetermined distance.

The motor controller 60 generates a position instruction based on the received drive instruction and a rotation position received from the encoder 61 E and outputs the position instruction to the drive circuit 61 D. The drive circuit 61 D generates drive current based on the received position instruction and outputs the drive current to the transport roller motor 61 M. The transport roller motor 61 M generates rotation based on the received drive current. This transports the transport tray T 2 to the predetermined position and then stops the transport tray T 2 at the predetermined position (step S 209 ) (refer to FIG. 10A ).

When the deviation between the rotation position, which is input to the motor controller 60 from the encoder 61 E, and the position instruction becomes less than or equal to a predetermined value, the motor controller 60 generates a position instruction to stop rotation generated with the transport roller motor 61 M and outputs the position instruction to the drive circuit 61 D. The drive circuit 61 D generates drive current based on the received position instruction and outputs the drive current to the transport roller motor 61 M. This stops rotation generated with the transport roller motor 61 M. Additionally, the motor controller 60 generates a completion signal, which indicates that the operation of the transport roller motor 61 M based on the drive instruction has been completed corresponding to the drive instruction, outputs the completion signal to the main controller 50 , and waits for a further drive instruction.

When receiving the completion signal, the main controller 50 generates a drive instruction to transport the transport tray T 2 by a predetermined distance toward the terminal end of the outgoing line R 1 in the forward direction and outputs the drive instruction to the motor controller 60 .

The motor controller 60 generates a position instruction based on the received drive instruction and a rotation position received from the encoder 61 E and outputs the position instruction to the drive circuit 61 D. The drive circuit 61 D generates drive current based on the received position instruction and outputs the drive current to the transport roller motor 61 M. Based on the received drive current, the transport roller motor 61 M generates rotation in a direction opposite to the reverse transportation (steps S 205 to S 209 ). This transports the transport tray T 2 in the forward direction along the outgoing line R 1 (step S 210 ) (refer to FIG. 10B ). The predetermined distance is set so that when moved by the predetermined distance, the transport tray T 2 is positioned between the irradiation position of the first ion source 21 L and the irradiation position of the second ion source 21 U on the outgoing line R 1 , that is, the transport tray T 2 faces the transport tray T 1 that has been stopped on the incoming line R 2 . In this manner, the transport tray T 2 is transported to the above position and stopped (step S 211 ) (refer to FIG. 10C ).

When the deviation between the rotation position, which the encoder 61 E outputs to the motor controller 60 , and the position instruction becomes less than or equal to a predetermined value, the motor controller 60 generates a completion signal, which indicates that the operation of the transport roller motor 61 M based on the drive instruction has been completed, and outputs the completion signal to the main controller 50 . Then, the main controller 50 temporarily ends the reverse transport process of the transport tray T 2 .

A situation, in which the output of the lower ion beams BL stops when the first ion source 21 L is irradiating the transport tray T 2 with lower ion beams BL on the outgoing line R 1 has been described above. However, such a reverse transport process may be performed when the irradiation of the transport tray T 2 with upper ion beams BU stops on the outgoing line R 1 , when the irradiation of the transport tray T 1 with upper ion beams BU stops on the incoming line R 2 , and when the irradiation of the transport tray T 1 with lower ion beams BL stops on the incoming line R 2 . In such cases, the reverse transport process is performed in the same manner as descried above although there may be differences in the driven one of the ion sources 21 L and 21 U that irradiates the transport tray T, the imaged one of the barcode groups C 1 and C 2 , the operated one of the barcode readers 23 B to 23 D that images the barcodes, and the transportation line of the transport tray T. When the ion beam irradiation of both transport trays T 1 and T 2 abnormally stop, reverse transport processes are simultaneously performed on the transport trays T 1 and T 2 .

In this manner, the irradiation position of ion beams on the substrate S when the relative movement stops, which is the position of the transport tray T relative to the imaging position detected in the corresponding image cycle, is stored as a stop position. After the transport tray T is transported to a region that is not irradiated with ion beams, the irradiation of ion beams is started again. Then, the transportation of the transport tray T and substrate S is started in the direction opposite to that when the previous ion beam irradiation was performed. When the position of the transport tray T relative to the imaging position reaches the stop position, the irradiation of ion beams is stopped.

In such a reverse transport process, the irradiation of ion beams can be performed on a region that has not been irradiated with ion beams. The irradiation of ion beams subsequent to the output stopping is performed by checking the profile of the ion beams and then performing transportation in the reverse direction. Thus, the substrate S is irradiated with ion beams of which output is further stabilized a certain level compared to when the irradiation is performed during transportation in the forward direction. This limits variations in the irradiation amount of ion beams over the plane of the substrate S and allows for the irradiation to be performed on the entire substrate S in the transport direction even when the irradiation of ion beams stops before completion.

Abnormal Beam Profile

In the ion beam irradiation process, when the output ion beams do not have the predetermined profile corresponding to the output instruction (step S 102 : NO), the ion beam controller 70 generates an output instruction based on the drive instruction received from the main controller 50 and the measurement data received from the first output sensor 71 S. Then, the ion beam controller 70 outputs the output instruction to the drive circuit 61 D again. The drive circuit 61 D generates drive current based on the output instruction and outputs the drive current to the first ion source 21 L. Then, the first ion source 21 L outputs ion beams. When the irradiation of ion beams is started based on the drive current that is changed in this manner, the first profile measurement unit 22 L outputs the measurement data of ion beams, which is obtained after the change, to the ion beam controller 70 .

The ion beam controller 70 compares the measurement data before and after changing the drive current. If the measurement data has been changed by a predetermined value, the ion beam controller determines that the profile of the ion beams is adjustable (step S 121 : YES) and again compares the profile of the ion beam output with the predetermined profile corresponding to the drive instruction (step S 102 ). If the profile of the ion beams is not adjustable (step S 121 : NO), the ion beam controller 70 generates an error signal, which indicates that the profile is not adjustable, and outputs the error signal to the main controller 50 (step S 122 ). Then, the main controller 50 temporarily ends the irradiation of ion beams.

Even when the adjustment of the output from the first ion source 21 L is completed (step S 102 : YES), as long as the adjustment of the output from the second ion source 21 U is not completed within a predetermined time (step S 102 : NO, step S 131 : YES), the main controller 50 temporarily ends the ion beam irradiation process.

In the same manner as the ion beam irradiation process, in the reverse transport process, when ion beams are not output in accordance with the predetermined profile corresponding to the output instruction (step S 204 : NO), the ion beam controller 70 generates an output instruction based on the drive instruction received from the main controller 50 and the measurement data received from the first output sensor 71 S and outputs the output instruction to the drive circuit 61 D again. The drive circuit 61 D generates drive current based on the updated output instruction and outputs the drive current to the first ion source 21 L. Then, the first ion source 21 L generates outputs according to the drive current. If the profile of ion beams is adjustable (step S 221 : YES), the process is repeated until the profile of ion beams is adjusted to the predetermined profile. If the profile of ion beams is not adjustable, the ion beam controller 70 generates an error signal, which indicates that the profile is not adjustable, and outputs the error signal to the main controller 50 (step S 222 ). When receiving the error signal, the main controller 50 temporarily ends the reverse transport process.

As described above, the present embodiment has the advantages described below.

(1) By imaging each barcode C 1 a , which indicates a position on the transport tray T, the position of the transport tray T relative to the imaging position is detected. The relative relation between an imaging position, where the barcode C 1 a is imaged, and an irradiation position, to which ion beams are emitted, is continuously maintained in a predetermined relationship during transportation of the transport tray T. Therefore, whenever the barcode readers 23 A to 23 D each detect the barcode C 1 a , the irradiation position relative to the transport tray T is detectable. This allows for the irradiation position of the transport tray T to be directly detected in comparison with when the position of the transport tray is detected from the operation amount of the transport unit, which transports the transport tray. Thus, even when there are differences between the transport roller 41 , which forms the transport unit that transports the transport tray T, and the transport tray T, errors resulting from such differences would be limited. This increases the accuracy for detecting an irradiation position of the substrate S, which is supported by the transport tray T.

(2) The detection result from each of the barcode readers 23 A to 23 D and the detection result from each of the output sensors 71 S and 72 S are associated with one another and stored in the memory 70 a . This allows for recognition of the portion of the substrate S irradiated with the desirable output of ion beams from information stored in the memory 70 a . In other words, the portion of the substrate S that is irradiated with an undesirable output of ion beams and the portion of substrate S that is not irradiated with ion beams may be recognized. This increases the accuracy of a process performed on a portion of the substrate S where the irradiation of ion beams is insufficient to compensate for the insufficient irradiation.

(3) Among the irradiation positions of the substrate S, the position where the output stops may be recognized. This increases the detection accuracy of the position where the output of ion beams stopped. Therefore, a further irradiation process may be performed with high accuracy on a portion of the substrate S that was not irradiated with ion beams.

(4) When detecting that the output of ion beams has been stopped, the position of the transport tray T relative to the imaging position is stored in the memory 70 a as the stop position associated with the stopping of the output. When the position of the transport tray T relative to the imaging position is between the stop position and the terminal position, ion beams are output again. Therefore, further irradiation of a portion that has not been irradiated with ion beams may be performed with high accuracy.

(5) When detecting that the output of ion beams has been stopped, the position of the transport tray T relative to the image position is stored in the memory 70 a as the stop position associated with the stopping of the output. After the transport tray T is transported to a non-irradiation position, the irradiation of ion beams is started again and the transportation of the transport tray T is started in the direction opposite to that of the previous irradiation. When the position of the transport tray T relative to the imaging position reaches the stop position, the irradiation of ion beams stops. Therefore, further irradiation of a portion of the substrate S that has not been irradiated with ion beams may be performed with high accuracy.

(6) After the output is stopped, the ion beam irradiation of the transport tray T, which is transported in the reverse direction, is performed. Thus, the substrate S is irradiated with ion beams, of which output is further stably maintained at the set value, compared with when the transport tray T is transported from the stop position in the forward direction. This limits variations in the irradiation amount over the substrate plane and allows for the irradiation amount to be uniform throughout the plane of the substrate S even when the output of ion beams stops before completion of the irradiation.

(7) A plurality of the barcodes C 1 a are applied to the transport tray T. More specifically, the barcodes C 1 a are applied to the transport tray T entirely from the front end to the rear end in the forward direction. This aspect allows for the position of the transport tray T relative to the imaging position to be obtained entirely from the front end to the rear end of the transport tray T. Thus, regardless of where the transport tray T is located in the forward direction, the accuracy for detecting the position of the transport tray T may be increased.

(8) The barcode readers 23 A to 23 D are each located at the side of the transport tray T opposite to the ion sources 21 L and 21 U. Thus, the barcodes groups C 1 and C 2 , which are imaged by the barcode readers 23 A to 23 D, are located at the same side of the transport tray T as the barcode readers 23 A to 23 D. In this aspect, each of the barcode groups C 1 and C 2 is located at the side of the transport tray that is not irradiated with ion beams. This limits deterioration in the outer appearance of each barcode group C 1 and C 2 caused by heat or the like of ion beams. Consequently, decreases are limited in the accuracy for detecting the irradiation position of ion beams that would be caused by the deteriorated outer appearance of each barcode group C 1 and C 2 .

(9) The barcode readers 23 A to 23 D are located at positions on the transport tray T that do not face the ion sources 21 L and 21 U. This limits heat deterioration of the imaging mechanism of each barcode reader 23 A to 23 D caused by heat or the like of ion beams. Consequently, decreases are limited in the accuracy for detecting the irradiation position of ion beams that would be caused by the deteriorated outer appearance of each barcode group C 1 and C 2 .

(10) The irradiation portion of the substrate S includes the lower region SL and the upper region SU. The lower region SL and the upper region SU are each irradiated by the different ion sources 21 L and 21 U. Under this situation, the irradiation of the substrate S is performed by a plurality of the ion sources 21 L and 21 U. Thus, the ion beam irradiation of the substrate S may be performed in various manners as compared to when the ion beam irradiation is performed on the substrate S with a single ion source. This easily realizes the desirable irradiation amount on the substrate plane. Additionally, adjustments may be made to the ion beam irradiation of each ion source 21 L and 21 U. This simplifies the ion beam irradiation of each ion source 21 L and 21 U and improves the throughput of the ion beam irradiation process as compared to a structure in which the regions of the ion beam irradiation overlap.

(11) The transport tray T includes the upper barcode group C 1 and the lower barcode group C 2 . The upper barcode group C 1 is arranged in the upper region SU of the transport tray T. The lower barcode group C 1 is arranged in the lower region SL of the transport tray T. When the upper region SU is irradiated with ion beams, the second barcode reader 23 B and the third barcode reader 23 C each image the lower barcode group C 2 . When the lower region SL is irradiated with ion beams, the first barcode reader 23 A and the fourth barcode reader 23 D each image the upper barcode group C 1 . Thus, ion beams output from the ion sources 21 L and 21 U reach the substrate S without being interfered by the barcode readers 23 A to 23 D. That is, the barcode readers 23 A to 23 D are not irradiated with ion beams output from the ion sources 21 L and 21 U. Thus, the irradiation of the substrate S with ion beams is not interfered. This increases the accuracy for detecting the irradiation position of ion beams.

The above embodiment may be modified as described below.

The ion beam irradiation device 10 may have a structure that does not include the reverse transport process. For example, while transporting the transport tray T in the forward direction, the ion beam irradiation device 10 may transport the transport tray T so that a portion, which has not been irradiated with ion beams, is irradiated again. Alternatively, the irradiation of a portion that has not been irradiated with ion beams may be performed by a different ion beam irradiation device. In this situation, a preferred structure allows for the transfer of data of the stop position between the two ion beam irradiation devices.

The barcode readers 23 A to 23 D may each be connected to a controller that differs from the ion beam controller 70 , for example, the main controller 50 .

The first barcode reader 23 A and the fourth barcode reader 23 D may be omitted. Alternatively, the second barcode reader 23 B and the third barcode reader 23 C may be omitted. Accordingly, one of the barcode groups C 1 and C 2 may be applied to one of the upper frame 31 b and the lower frame 31 c in accordance with the location of the barcode readers.

Each of the barcode groups C 1 and C 2 may be arranged in such a manner that the barcode indicating 0 mm is applied to the front end of the transport tray T in the reverse direction, and the barcode indicating 2700 mm is applied to the rear end of the transport tray T in the reverse direction.

The barcode groups C 1 and C 2 may be directly marked on the transport tray T instead of using a tape applied to the transport tray T.

A modified example of the barcode groups C 1 and C 2 applied to the transport tray T will now be described with reference to FIG. 11 . For the same reason as described above, a portion of the upper barcode group C 1 will be described below. FIG. 11 shows the upper barcode group C 1 as viewed from the first barcode reader 23 A.

As shown in FIG. 11 , the upper barcode group C 1 includes a plurality of the barcodes C 1 a . A plurality of bars forming the barcode C 1 a are each printed in a direction parallel to the transport direction. In contrast, as shown in FIG. 3A , in the present embodiment, a plurality of bars forming the barcode C 1 a are each printed in a direction orthogonal to the transport direction. The numerical value C 1 b is printed at the right side of the corresponding barcode C 1 a in the transport direction. Alternatively, the numerical value C 1 b may be printed at the left side of the corresponding barcode C 1 a in the transport direction, or above or below the corresponding barcode C 1 a . In the same manner as the barcode C 1 a in the present embodiment, each barcode C 1 a is surrounded by a blank portion C 1 c.

Each of the first barcode reader 23 A and the fourth barcode reader 23 D, which reads the upper barcode group C 1 , includes an imaging unit that images the upper barcode group C 1 in a predetermined cycle. The barcode readers 23 A and 23 D each detect, from the image of the upper barcode group C 1 captured by the imaging unit, the position of the transport tray T relative to the imaging position. The imaging unit obtains an image, which is included within a predetermined imaging range. A width of the imaging range in the direction orthogonal to the transport direction is set as a dimension that includes every one of the bars forming each barcode C 1 a and the blank portion C 1 c including portions located above and below the barcode C 1 a.

When the image captured by the imaging unit includes “000183” as shown in FIG. 11 , that is, the barcode C 1 a indicating a position separated by 183 mm from one end of the upper frame 31 b , each of the barcode readers 23 A and 23 D sequentially converts the image to binary data, for example, from the lower side. The barcode readers 23 A and 23 D each decode the binary data and detect the length from the front end of the upper frame 31 b in the forward direction to the imaging position, which is the position of the transport tray T relative to the imaging position, in a predetermined cycle.

As compared with the arrangement shown in FIG. 3A , when the barcode group C 1 is arranged as shown in FIG. 11 , the transport position of the transport tray T may be detected with higher decoding performance. More specifically, in the structure of FIG. 11 , the barcodes C 1 a are each located parallel to the transport direction. This allows for more barcode groups C 1 to be arranged within the same region (upper frame or lower frame) as compared with the structure in FIG. 3A . This shortens the reading interval of each barcode C 1 a in the transport direction and improves the detection resolution of the transport position using each barcode C 1 a . Thus, the accuracy for position detection of the transport tray T is increased.

The irradiation position of each ion source 21 L and 21 U may be a position extending throughout the heightwise direction of the substrate S or a position divided into three or more portions in the heightwise direction of the substrate S. It is only necessary for the irradiation position to cover the entire direction of the substrate S in a direction intersecting the transport direction.

The same region of the substrate S may be irradiated with ion beams three or more times. Also, the same region of the substrate S may be irradiated with ion beams just once.

The transport tray T may be transported held upright to be orthogonal to the bottom wall of the processing chamber 14 .

The barcode readers 23 A to 23 D may be located at the same side as the ion sources 21 L and 21 U. In such a structure, the barcode groups C 1 and C 2 , which are included in the transport tray T, is applied to the side of the tray frame 31 that is irradiated with ion beams.

An index included in the transport tray T is not limited to a barcode. The index may be a two-dimensional code or only the numerical value described above. It is only necessary that different indices be arranged in the transport direction to indicate positions of the transport tray.

A position detector may be located at a position facing the irradiation position of an ion beam irradiation unit. In this case, a preferred structure includes a separate shield portion, which shields ion beams, so that the position detector is not irradiated with ion beams emitted to the irradiation position.

Each output sensor 71 S and 72 S serving as an output detector, which detects the output of ion beams, is not limited to a sensor outputting the detection result when detecting that the amount of the current flowing through a filament, which is the output value of ion beams, is less than or equal to a predetermined value. Each output sensor 71 S and 72 S may be a sensor outputting the output value of ion beams as the detection result. In this case, preferably, a separate ion beam controller determines whether or not the output of ion beams is less than or equal to the predetermined value. When the output detector, which detects the output of ion beams, outputs the output value of ion beams as the detection result, the detection result of the position detector may be associated with the detection result of the output detector and stored in predetermined cycles. In such a structure, the irradiation amount of each portion on the entire substrate S may be obtained. The ion beam irradiation device may omit such an output detector.

A detection cycle in which the output detector detects the output value of ion beams may differ from that in which the position detector detects the position of the transport tray. It is only necessary for the detection result of the position detector and the latest detection result of the output detector obtained during the corresponding position detection to be stored in association.

In the present embodiment, when the output of ion beams abnormally stops, the substrate S transported in the reverse direction is irradiated, with ion beams, toward the stop position. Instead, when the output of ion beams decreases, the irradiation of ion beams may be performed in a manner described below.

For example, the first output sensor and the second output sensor are sensors that detect temporal and spatial profiles of ion beams output from the ion sources 21 L and 21 U. When detecting that the profile is less than or equal to a threshold, each output sensor generates an output decline signal, which indicates that the output of ion beams has decreased, and outputs the output decrease signal to the ion beam controller 70 . Also, each output sensor detects the profile of ion beams and outputs the detected profile to the ion beam controller 70 in each predetermined period from when the output decline signal is generated to when transportation of the transport tray in the forward direction is completed.

When receiving the output decline signal, the ion beam controller 70 stores the position data obtained in the imaging cycle, in which the output decrease signal is received, as a decrease position, in which the output of ion beams is decreased. Also, the ion beam controller 70 stores the profile received from each output sensor in association with the position data obtained in imaging cycle, in which each profile is received.

When ion beam irradiation is performed on the substrate S transported in the reverse direction, the ion beam controller 70 outputs a drive instruction, which is received from the main controller 50 , and an output instruction, which is based on the stored profile and position data, to the drive circuits 71 D and 71 D.

Each of the drive circuits 71 D and 72 D generates drive current of each ion source 21 L and 21 U based on the output instruction received from the ion beam controller 70 and outputs the drive current to the corresponding one of the ion sources 21 L and 21 U. In this manner, each ion source 21 L and 21 U outputs ion beams corresponding to the received drive current. This allows for the output of ion beams to be corrected based on the stored profile and position data. The irradiation of such ion beams is stopped when the position of the transport tray T relative to the imaging position reaches the output decline position.

This limits variations in the irradiation amount of ion beams over the plane of the substrate S even when the irradiation of ion beams decreases during transportation. The electrical configuration of the ion beam irradiation device 10 is not limited to the above configuration. As long as the ion beam irradiation device 10 is configured to correct the output of ion beams during the reverse transportation based on variations of the ion beam profile and the corresponding position of the transport tray, the same advantages may be obtained.

In the present embodiment of FIG. 3A and the modified example of FIG. 11 , the barcode C 1 a is employed as an index to detect the position of the transport tray T. However, another index may be employed instead of the barcode. For example, a two-dimensional code such as a QR CODE (registered trademark) may be employed as an index. When a two-dimensional code is employed, not only position information, which indicates the position of the transport tray T, but also other information such as a product number of the substrate S are included in the two-dimensional code. Consequently, a variety of information may be obtained from the index.