Gas ring and method of processing substrates

1. Field of the Invention

The present invention relates generally to semiconductor processing equipment. More particularly, the present invention relates to a gas ring for a pancake reactor and to a method for using the same.

2. Description of Related Art

As is well known to those of skill in the art, substrate processing typically involved the formation of one or more layers on substrates. Generally, substrates, e.g., silicon wafers, were placed on a susceptor in a semiconductor processing reactor. Process gas was introduced into the semiconductor processing reactor, and a layer was formed on the substrates from the process gas.

To insure uniformity in the characteristics of the substrates, it was important that the formed layer was uniform, e.g., in thickness, across the substrates. To enhance the uniformity of the formed layer, the susceptor upon which the substrates were placed was typically rotated within the semiconductor processing reactor.

Further, the flow characteristics of the process gas through the semiconductor processing reactor was important. Typically, gas injectors located in and extending from the bottom of the semiconductor processing reactor injected the process gas upwards towards the dome of the semiconductor processing reactor above the susceptor. The process gas was then drawn down and around the susceptor to exhaust ports also located in the bottom of the semiconductor processing reactor. Thus, the process gas flow through the semiconductor processing reactor was turbulent and recirculatory. Due to the turbulent and recirculatory flow of process gas, particulates located within the semiconductor processing reactor has a tendency to become dislodged and contaminated the substrates.

Further, since all of the process gas had to flow pass the edge of the susceptor to the exhaust ports located in the bottom of the semiconductor processing reactor, the deposited layer was generally thicker near the edge of the susceptor and thinner near the center of the susceptor.

In accordance with one embodiment of the present invention, a gas ring includes at least one gas injector port and at least one gas exhaust port. The at least one gas injector port is opposite the at least one gas exhaust port.

A process gas to a reactor volume of a semiconductor processing reactor is provided through the at least one gas injector port of the gas ring. The process gas flows horizontally from the at least one gas injector port across a principal surface of a rotating susceptor to the at least one exhaust port. The spent process gas is removed from the reactor volume through the at least one exhaust port.

In one embodiment, the process gas flows horizontally with a laminar or non-turbulent flow, i.e., in a sheet-like flow. This results in the formation of layers on substrates having excellent thickness uniformity.

Further, by reducing or eliminating turbulence in the flow of the process gas through the reactor volume, dislodgement of particulates and the associated substrate contamination is minimized.

In addition, use of the gas ring allows realization of an abrupt transition between layers formed on the substrates.

Embodiment in accordance with the present invention will be more readily apparent from the detailed description set forth below taken in conjunction with the accompanying drawings.

FIG. 1 is a side cross-sectional view of a pancake reactor in accordance with one embodiment of the present invention;

FIG. 2 is a top cross-sectional view of the pancake reactor of FIG. 1 ;

FIGS. 3 and 4 are perspective views from the inlet and outlet side, respectively, of a chassis of a gas ring of FIGS. 1 and 2 in accordance with one embodiment of the present invention;

FIG. 5 is a top plan view, partially cutaway, of the chassis of FIGS. 3 and 4 in accordance with one embodiment of the present invention;

FIG. 6 is a cross-sectional view of the chassis along the line VI-VI of FIG. 5 in accordance with one embodiment of the present invention;

FIG. 7 is a cross-sectional view of the chassis along the line VII-VII of FIG. 5 in accordance with one embodiment of the present invention;

FIG. 8 is a cross-sectional view of the chassis along the line VIII-VIII of FIG. 5 in accordance with one embodiment of the present invention;

FIG. 9 is a side plan view of the chassis of FIG. 5 in accordance with one embodiment of the present invention;

FIG. 10 is a cross-sectional view of the chassis along the line X-X of FIG. 9 in accordance with one embodiment of the present invention;

FIG. 11 is a cross-sectional view of the chassis along the line XI-XI of FIG. 10 in accordance with one embodiment of the present invention;

FIG. 12 is an enlarged cross-sectional view of the region XII of the chassis of FIG. 11 in accordance with one embodiment of the present invention;

FIG. 13 is an exploded perspective partial view of a gas ring illustrating the mounting of a gas injector head in a gas injector head port in accordance with one embodiment of the present invention;

FIG. 14 is a partial cross-sectional view of a gas injector head in accordance with another embodiment of the present invention;

FIG. 15 is a front plan view of the gas injector head along the line XV of FIG. 14 in accordance with one embodiment of the present invention;

FIGS. 16 , 17 , 18 , 19 and 20 are cross-sectional views of the gas injector head taken along the lines XVI-XVI, XVII-XVII, XVIII-XVIII, XIX-XIX, XX-XX of FIG. 14 , respectively, in accordance with various embodiments of the present invention;

FIG. 21 is a partial top cross-sectional view of a pancake reactor in accordance with one embodiment of the present invention;

FIG. 22 is a partial top cross-sectional view of a gas injector head of FIG. 21 in accordance with one embodiment of the present invention;

FIG. 23 is a front plan view of the gas injector head along the line XXIII of the pancake reactor of FIG. 22 in accordance with one embodiment of the present invention;

FIG. 24 is a partial top cross-sectional view of a gas injector head of the pancake reactor of FIG. 21 in accordance with another embodiment of the present invention; and

FIG. 25 is a front plan view of the gas injector head along the line XXV of FIG. 24 in accordance with one embodiment of the present invention.

In the following description, the same or similar elements are labeled with the same or similar reference numbers.

Referring to FIG. 1 , a process gas to a reactor volume 118 of a semiconductor processing reactor 100 is provided through gas injector ports 120 of a gas ring 106 . The process gas flows horizontally as indicated by arrows 128 from gas injector ports 120 across a principal surface 108 P of a rotating susceptor 108 to gas exhaust ports 122 of gas ring 106 . The spent process gas is removed from reactor volume 118 through gas exhaust ports 122 .

In one embodiment, the process gas flows horizontally with a laminar or non-turbulent flow, i.e., in a sheet-like flow. This results in the formation of layers on substrates having excellent thickness uniformity.

Further, by reducing or eliminating turbulence in the flow of the process gas through reactor volume 118 , dislodgement of particulates and the associated substrate contamination is minimized.

In addition, use of gas ring 106 allows realization of an abrupt transition between layers formed on the substrates.

More particularly, FIG. 1 is a side cross-sectional view of a pancake reactor 100 , sometimes called a semiconductor processing reactor, in accordance with one embodiment of the present invention. FIG. 2 is a top cross-sectional view of pancake reactor 100 of FIG. 1 .

Referring now to FIGS. 1 and 2 together, pancake reactor 100 includes a base 102 , a dome 104 , e.g., a quartz bell jar or dome, and a gas ring 106 between base 102 and dome 104 . Located within base 102 is a rotating susceptor 108 .

Rotating susceptor 108 rotates around an axis 110 of rotating susceptor 108 . Rotating susceptor 108 includes substrate holders 112 . Substrate holders 112 support substrates (not shown), e.g., silicon wafers, although other substrates are used in other embodiments. Thus, rotation of rotating susceptor 108 also rotates the substrates to optimize the thickness uniformity of layer(s) formed on the substrates. However, in another embodiment, rotating susceptor 108 and thus the substrates are not rotated.

Although five substrate holders 112 are illustrated in FIG. 2 , it is understood that more or less than five substrate holders 112 , e.g., three, are used in other embodiments.

O-rings 114 are located within circular O-ring grooves 115 of base 102 and form a seal between base 102 and a lower, e.g., first, surface 106 L of gas ring 106 . Similarly, O-rings 116 are located within circular O-ring grooves 117 of gas ring 106 and form a seal between an upper, e.g., second, surface 106 U of gas ring 106 and dome 104 .

Accordingly, base 102 , gas ring 106 , and dome 104 define a reactor volume 118 , sometimes called a processing region or space.

Gas ring 106 includes at least one gas injector port 120 , hereinafter referred to as gas injector ports 120 , and at least one gas exhaust port 122 , hereinafter referred to as gas exhaust ports 122 . In accordance with this embodiment, gas injector ports 120 and gas exhaust ports 122 lie in a common horizontal plane H parallel to a principal surface 108 P of rotating susceptor 108 and are opposite one another. In one embodiment, principal surface 108 P lies in a horizontal plane. As used herein, horizontal and similar terms mean in a first direction and vertical and similar terms mean in a second direction perpendicular to the first direction.

During use, process gas is provided to gas ring 106 through at least one gas inlet port 124 , hereinafter referred to as gas inlet ports 124 , coupled to gas injector ports 120 . The process gas exits gas ring 106 through gas injector ports 120 and enters into reactor volume 118 .

The process gas flows horizontally from gas injector ports 122 across principal surface 108 P of rotating susceptor 108 to exhaust ports 122 . The process gas is removed from reactor volume 118 through exhaust ports 122 and enters gas ring 106 . The process gas is exhausted from gas ring 106 through at least one gas outlet port 126 , hereinafter gas outlet ports 126 , coupled to exhaust ports 122 .

By locating gas injector ports 120 and gas exhaust ports 122 horizontally opposite one another, the process gas flows horizontally across principal surface 108 P of rotating susceptor 108 and thus across the substrates uniformly as indicated by the arrows 128 . In one embodiment, the process gas flows horizontally with a laminar or non-turbulent flow, i.e., in a sheet-like flow. This results in the formation of layers on substrates having excellent thickness uniformity.

Further, by reducing or eliminating turbulence in the flow of the process gas through reactor volume 118 , dislodgement of particulates and the associated substrate contamination is minimized.

In addition, use of gas ring 106 allows realization of an abrupt transition between layers formed on the substrates. This is because when the process gas is changed to have a new composition, e.g., from a high dopant concentration process gas to a low dopant concentration process gas, the new process gas travels in a uniform horizontal flow through pancake reactor 100 as indicated by the arrows 128 .

Accordingly, the composition of the process gas contacting the substrates abruptly changes when the process gas is changed. As a result, an abrupt transition occurs between the layer formed from the process gas having the original gas composition and the new layer formed from the process gas having the new gas composition. Thus, use of gas ring 106 enables formation of substrates having abrupt transitions between layers using a relatively simple, reliable and cost effective pancake reactor 100 .

See Moore et al., U.S. Pat. No. 6,475,284, issued Nov. 5, 2002, entitled “GAS DISPERSION HEAD”, which is herein incorporated by reference in its entirety, regarding achievement of abrupt transitions between layers on a substrate using uniform gas flow.

FIGS. 3 and 4 are perspective views from the inlet and outlet side, respectively, of a chassis 130 , sometimes called a main weldment, of gas ring 106 of FIGS. 1 and 2 in accordance with one embodiment of the present invention.

Referring now to FIGS. 1 , 2 , 3 and 4 together, chassis 130 , and more generally, gas ring 106 , includes upper surface 106 U, lower surface 106 L, an inner, e.g., third, surface 106 I, and an outer, e.g., forth, surface 1060 . In accordance with this embodiment, upper and lower surfaces 106 U, 106 L are annular and lie in horizontal planes. Inner surface 106 I and outer surface 1060 extend between upper and lower surfaces 106 U, 106 L and are generally cylindrical.

FIG. 5 is a top plan view, partially cutaway, of chassis 130 of FIGS. 3 and 4 in accordance with one embodiment of the present invention. FIG. 6 is a cross-sectional view of chassis 130 along the line VI-VI of FIG. 5 in accordance with one embodiment of the present invention.

Referring now to FIGS. 5 and 6 together, upper surface 106 U includes O-ring grooves 117 A, 117 B, collectively referred to as O-ring grooves 117 . O-ring grooves 117 are circular and concentric with upper surface 106 U.

Upper surface 106 U further includes a circular purge groove 502 , which is concentric with upper surface 106 U and O-ring grooves 117 . Purge groove 502 is located inwards closer to inner surface 106 I of chassis 130 than O-ring grooves 117 , i.e., purge groove 502 has a smaller diameter than either of O-ring grooves 117 .

Upper surface 106 U further includes upper purge ports 506 A, 506 B, collectively referred to as upper purge ports 506 . Upper purge ports 506 are located within purge groove 502 . Although two upper purge ports 506 are illustrated, in one embodiment, only a single purge port 506 is used.

Upper purge ports 506 A, 506 B are coupled to lower purge ports in 602 A, 602 B, lower surface 106 L by purge port channels 604 A, 604 B, respectively. Purge port channels 604 A, 604 B, collectively referred to as purge port channels 604 , extend between upper purge ports 506 and lower purge ports 602 A, 602 B, collectively referred to as lower purge ports 602 . In one embodiment, purge port channels 604 are ¼″ OD×0.035″ WALL 316 L SST tubes although other channels are used in other embodiments.

During use, a purge gas, e.g., an inert gas such as argon or nitrogen, is provided to lower purge ports 602 from base 102 . The purge gas passes through purge port channels 604 and exits upper purge ports 506 into purge groove 502 .

In one embodiment, the pressure of the purge gas in purge groove 502 is greater than the pressure of the process gas within reactor volume 118 such that any leakage of gas is leakage of inert gas into pancake reactor 100 and not leakage of process gas between gas ring 106 , base 102 and dome 104 .

FIG. 7 is a cross-sectional view of chassis 130 along the line VII-VII of FIG. 5 in accordance with one embodiment of the present invention. Referring now to FIGS. 5 and 7 together, upper surface 106 U further includes an upper vacuum port 508 . Upper vacuum port 508 is located between O-ring grooves 117 A and 117 B.

Upper vacuum port 508 is coupled to a lower vacuum port 706 in lower surface 106 L by a vacuum port channel 708 . Vacuum port channel 708 extends between upper vacuum port 508 and lower vacuum port 706 . In one embodiment, vacuum port channel 708 is a ⅛″ OD×0.025″ Wall 316 L SST tube although other channels are used in other embodiments.

During use, vacuum is provided to lower vacuum port 706 from base 102 . The vacuum passes through vacuum port channel 708 and exits upper vacuum port 508 .

By applying vacuum between O-ring grooves 117 A and 117 B, any leakage of gas past O-ring grooves 117 is leakage of the gas into upper vacuum port 508 and not vice versa. In this manner, leakage of process gas between gas ring 106 , base 102 and dome 104 is redundantly prevented.

Referring now to FIGS. 4 , 5 and 6 together, chassis 130 includes first and second cooling fluid couplings 410 A, 410 B, collectively referred to as cooling fluid couplings 410 . Chassis 130 further includes a first internal cooling channel 610 coupled to cooling fluid couplings 410 . Internal cooling channel 610 includes split upper and lower channels 612 A, 612 B as illustrated in FIG. 6 .

As shown in the cutaway view of FIG. 5 , a baffle 510 is located between cooling fluid couplings 410 A, 410 B.

During use, water or other cooling fluid, hereinafter referred to as water for simplicity of discussion, is provided to cooling fluid coupling 410 A (or 410 B). The water passes through cooling fluid coupling 410 A (or 410 B) and into internal cooling channel 610 . Baffle 510 causes the water to flow around the entire circumference of chassis 130 through internal cooling channel 610 and to fluid coupling 410 B (or 410 A). The water then exits through fluid coupling 410 B (or 410 A). In one embodiment, chilled water is used.

By passing water through internal cooling channel 610 as discussed above, chassis 130 and thus gas ring 106 is kept cool and prevented from becoming heated. This prevents undesirable deposition on gas ring 106 from the process gas. To further avoid deposition on gas ring 106 , in one embodiment, inner surface 106 I is provided with a coating of quartz, silicon carbide or other infrared (IR) transparent material. This minimizes heating of inner surface 106 I and the associated deposition on inner surface 106 I.

FIG. 8 is a cross-sectional view of chassis 130 along the line VIII-VIII of FIG. 5 in accordance with one embodiment of the present invention. Referring now to FIGS. 3 , 4 , 5 and 8 together, inner surface 106 I includes an inner thermocouple port 412 and outer surface 1060 includes an outer thermocouple port 302 . Inner thermocouple port 412 is coupled to outer thermocouple port 302 by a thermocouple channel 802 , e.g., a tube. Thermocouple channel 802 extends between inner thermocouple port 412 and outer thermocouple port 302 .

In accordance with this embodiment, a flange 304 located at outer thermocouple port 302 is provided for mounting of a thermocouple (not shown) to gas ring 106 .

During use, a thermocouple is passed through outer thermocouple port 302 , through thermocouple channel 802 and into pancake reactor 100 through inner thermocouple port 412 . A gas tight seal with the thermocouple is formed using flange 304 .

Further, as shown in FIG. 8 , inner surface 106 I is provided with a coating of quartz, silicon carbide or other infrared (IR) transparent material 804 . Inner thermocouple port 412 extends through IR transparent material 804 .

As also shown in FIG. 8 , chassis 130 includes an upper gas ring plate 820 and a lower gas ring plate 822 . In this embodiment, upper and lower gas ring plates 820 , 822 are annular shaped plates.

An upper surface 820 U of upper gas ring plate 820 defines a portion of upper surface 106 U of gas ring 106 . Similarly, a lower surface 822 L of lower gas ring plate 822 defines a portion of lower surface 106 L of gas ring 106 .

In one embodiment, internal cooling channel 610 is machined into a main body 830 of chassis 130 . After formation of internal cooling channel 610 , upper and lower gas ring plates 820 , 822 are secured, e.g., by welding, to main body 830 of chassis 130 thus sealing internal cooling channel 610 . However, in another embodiment, chassis 130 is integral, i.e., is a single piece and not a plurality of separate pieces 820 , 822 and 830 coupled together.

FIG. 9 is a side plan view of chassis 130 of FIG. 5 in accordance with one embodiment of the present invention. FIG. 10 is a cross-sectional view of chassis 130 along the line X-X of FIG. 9 in accordance with one embodiment of the present invention. FIG. 11 is a cross-sectional view of chassis 130 along the line XI-XI of FIG. 10 in accordance with one embodiment of the present invention.

Referring now to FIGS. 2 , 9 , 10 , and 11 together, chassis 130 includes gas outlet ports 126 A, 126 B, collectively gas outlet ports 126 . Gas outlet ports 126 include flanges for coupling an exhaust line (not shown) to gas outlet ports 126 .

Gas outlet ports 126 A, 126 B are coupled to gas exhaust ports 122 A, 122 B, sometimes called first and second gas exhaust ports, by gas outlet channels 202 A, 202 B, respectively. In accordance with this embodiment, gas outlet channels 202 A, 202 B, collectively referred to as gas outlet channels 202 , are bent 90 degrees from gas exhaust ports 122 to gas outlet ports 126 . More particularly, gas outlet channels 202 are bent from the horizontal to the vertical.

Chassis 130 includes third and fourth cooling fluid couplings 902 A, 902 B, collectively referred to as cooling fluid couplings 902 . Chassis 130 further includes a second internal cooling channel 904 coupled to cooling fluid couplings 902 .

Internal cooling channel 904 includes a first jacket 1010 A around gas outlet channel 202 A, a second jacket 1010 B around gas outlet channel 202 B, and a jacket connector channel 910 , e.g., a tube, coupling jacket 1010 A with jacket 1010 B.

During use, water or other cooling fluid, hereinafter referred to as water for simplicity of discussion, is provided to cooling fluid coupling 902 A (or 902 B). The water passes through cooling fluid coupling 902 A (or 902 B) and into jacket 1010 A (or jacket 1010 B). The water flows from jacket 1010 A (or jacket 1010 B) to jacket 1010 B (or jacket 1010 A) through jacket connector channel 910 . The water then exits through cooling fluid coupling 902 B (or 902 A). In one embodiment, chilled water is used.

By passing water through internal cooling channel 904 as discussed above, gas outlet channels 202 are kept cool and prevented from becoming heated. This prevents undesirable deposition within gas outlet channels 202 from the spent process gas.

Referring now to FIGS. 1 and 10 together, lower surface 106 L of gas ring 106 is planar, sometimes called smooth. This facilitates the formation of a gas tight seal with O-rings 114 .

In one embodiment, gas ring 106 is provided as a retrofit kit for pancake reactor 100 . In accordance with this embodiment, an upper seal surface 102 U of base 102 is designed to form a seal with a lower seal surface 104 L of dome 104 , i.e., pancake reactor 100 is designed to be used without gas ring 106 .

However, to facilitate use of gas ring 106 , upper surface 106 U of gas ring 106 is similar if not identical to upper seal surface 102 U of base 102 . Similarly, lower surface 106 L of gas ring 106 is similar if not identical to lower seal surface 104 L of dome 104 . Accordingly, pancake reactor is easily retrofit with gas ring 106 , and gas ring 106 is thus sometimes called a retrofit gas ring.

However, in another embodiment, gas ring 106 is integral with and forms a part of base 102 and/or dome 104 .

Referring now to FIGS. 2 , 3 and 4 together, chassis 130 includes a gas exhaust manifold 204 in inner surface 106 I. Gas exhaust ports 122 are located within gas exhaust manifold 204 .

Gas exhaust manifold 204 is a collector of spent process gas from reactor volume 118 . More particularly, gas exhaust manifold 204 includes one or more pockets in inner surface 106 I, which function to remove the process gas from reactor volume 118 in a uniform manner.

As shown in FIG. 2 , gas exhaust manifold 204 includes a first pocket 206 A and a second pocket 206 B. Gas exhaust ports 122 A, 122 B are located within pockets 206 A, 206 B, respectively.

Chassis 130 further includes four gas injector head ports 306 A, 306 B, 306 C, and 306 D, collectively referred to as gas injector head ports 306 . Gas injector head ports 306 extend through chassis 130 from outer surface 1060 to inner surface 106 I. As discussed further below, gas injector heads are mounted within gas injector head ports 306 .

FIG. 12 is an enlarged cross-sectional view of the region XII of chassis 130 of FIG. 11 in accordance with one embodiment of the present invention. FIG. 13 is an exploded perspective partial view of gas ring 106 illustrating the mounting of a gas injector head 208 B in gas injector head port 306 B in accordance with one embodiment of the present invention.

Referring now to FIGS. 2 , 12 and 13 together, gas injector head port 306 B includes a first narrow section 210 and a second wide section 212 . Narrow section 210 has a width in both the horizontal and vertical direction less than a width of wide section 212 . Accordingly, injector head port 306 includes a vertical stop 214 , i.e., a vertical surface, where narrow section 210 joins wide section 212 .

Gas injector head 208 B includes an inner body section 1304 , an outer body section 1306 , and a protruding lip 1308 , which corresponds with stop 214 . More particularly, lip 1308 is located between and protrudes from inner body section 1304 and outer body section 1306 . In one embodiment, gas injector head 208 B is an integral single piece of quartz, silicon carbide or other infrared (IR) transparent material. This minimizes heating of gas injector head 208 B and the associated deposition on gas injector head 208 B from the process gas.

To mount gas injector head 208 B within gas injector head port 306 B, gas injector head 208 B is slid into gas injector head port 306 B with inner body section 1304 being inserted first. Gas injector head 208 B is slid into gas injector head port 306 B until lip 1308 butts up against, sometimes called contacts, stop 214 . In this manner, gas injector head 208 B is precisely positioned within gas injector head port 306 B and, more generally, within chassis 130 .

Outer body section 1306 includes first and second mounting apertures 1310 A, 1310 B. A gas injector head mounting assembly 216 B includes a seal plate 218 B and a gas dispersion manifold 220 B. Gas dispersion manifold 220 B includes mounting apertures 1314 A, 1314 B, which correspond to mounting apertures 1310 A, 1310 B of outer body section 1306 .

To mount gas dispersion manifold 220 B to gas injector head 208 B, mounting apertures 1314 A, 1314 B of gas dispersion manifold 220 B are aligned with mounting apertures 1310 A, 1310 B of outer body section 1306 , respectively.

A pin 1316 A is passed through apertures 1314 A and 1310 A. Similarly, a pin 1316 B is passed through apertures 1314 B and 1310 B. Pins 1316 A, 1316 B thus mount gas dispersion manifold 220 B to gas injector head 208 B. Gas dispersion manifold 220 B is mounted within gas injector head port 306 B along with gas injector head 208 B.

As discussed further below, gas injector head 208 B includes a plurality of gas injection channels. Gas dispersion manifold 220 B is a hollow sleeve, which disperses the process gas to the gas injection channels.

Gas injector head port 306 B is sealed at outer surface 1060 with seal plate 218 B. Seal plate 218 B includes an inner, e.g., first, surface 222 and an outer, e.g., second, surface 224 .

Inner surface 222 includes an O-ring groove 226 ( FIG. 2 ) in which an O-ring 228 is placed to form a seal between outer surface 1060 of chassis 130 and inner surface 222 of seal plate 218 B.

Seal plate 218 B is mounted to chassis 130 using screws 230 , which pass through mounting apertures 1320 of seal plate 218 B and into threaded mounting apertures 1322 of chassis 130 .

Seal plate 218 B further includes a gas inlet port 124 at outer surface 224 , coupled to a process gas line 1324 . Gas inlet port 124 is coupled to a gas outlet port 232 at inner surface 222 of seal plate 218 B by a gas channel 234 of seal plate 218 B.

During use, process gas is provided to process gas line 1324 . This process gas flows through gas inlet port 124 , through gas channel 234 and out of gas outlet port 232 into gas dispersion manifold 220 B to gas injector head 208 B. As stated above, gas dispersion manifold 220 B is a hollow sleeve and distributes the process gas from gas outlet port 232 , e.g., a single aperture, to the gas injection channels of gas injector head 208 B.

However, in another embodiment, instead of forming gas injector head mounting assembly 216 B from a separate seal plate 218 B and gas dispersion manifold 220 B, gas injector head mounting assembly 216 B is a single piece and not a plurality of separate pieces connected together.

To illustrate, referring now to FIG. 2 , a second gas injector head mounting assembly 216 A is used to mount a second gas injector head 208 A. Gas injector head mounting assembly 216 A includes an integral seal plate 218 A and gas dispersion manifold 220 A. Further, outer surface 1060 includes an O-ring groove 240 in which an O-ring 242 is placed to form a seal between outer surface 1060 of chassis 130 and an inner surface 222 of seal plate 218 A.

Gas injector head mounting assemblies 216 C, 216 D are similar to gas injector head mounting assembly 216 A and are used to mount gas injector heads 208 C, 208 D, respectively, in a similar manner.

Referring again to FIG. 2 , gas injector head 208 A includes an inner surface 250 and an outer surface 252 . Inner surface 250 is a concave vertical surface. More particularly, inner surface 250 is a segment of the cylindrical inner surface 106 I of chassis 130 . Outer surface 252 is a vertical plane in accordance with this embodiment.

Gas injector ports 120 of gas injector head 208 A are formed in inner surface 250 . Gas injector intake ports 254 are formed in outer surface 252 .

Gas injector head 208 A includes a plurality of gas injection channels 256 extending from and coupling gas injector intake ports 254 to gas injector ports 120 . In one embodiment, gas injection channels 256 are cylindrical apertures, sometimes called passageways, through gas injector head 208 A. Although four gas injection channels 256 are illustrated, more, e.g., five or ten, or less than four gas injection channels 256 are formed in other embodiments. For example, a gas injector head having five gas injection channels is illustrated in FIGS. 14-20 in accordance with one embodiment as discussed further below and gas injector head 208 B includes ten gas injection channels 256 as shown in FIG. 2 .

In one embodiment, referring now to FIGS. 1 and 2 together, gas injection channels 256 lie in a common horizontal plane parallel to a principal surface 108 P of rotating susceptor 108 (see FIG. 1 ). However, in other embodiments, one or more or all of gas injection channels 256 point up and/or down relative to principal surface 108 P of rotating susceptor 108 .

Further, gas injection channels 256 are angled, i.e., not perpendicular, relative to inner surface 250 and outer surface 252 of gas injector head 208 A.

More particularly, referring now to FIG. 2 , gas injector heads 208 include gas injection channels 256 . Gas injection channels 256 are parallel to one another in accordance with this embodiment. More generally, gas injection channels 256 point across pancake reactor towards gas exhaust ports 122 . In this manner, uniform flow of process gas through pancake reactor is achieved.

Since gas injection channels 256 are parallel to one another in accordance with this embodiment, the angle of gas injection channels 256 relative to inner surface 250 and outer surface 252 of gas injector heads 208 depends upon the position of the particular gas injector head 208 on the circumference of gas ring 106 .

More particularly, the closer a gas injector head 208 to gas exhaust ports 122 , the lesser the angle of gas injection channels 256 relative to inner surface 250 and outer surface 252 of the gas injector head.

To illustrate, an angle A between gas injection channels 256 and outer surface 252 of gas injector head 208 D is less than an angle B between gas injection channels 256 and outer surface 252 of gas injector head 208 C. Gas injector head 208 D is closer to gas exhaust ports 122 .

FIG. 14 is a partial cross-sectional view of a gas injector head 208 A- 1 in accordance with another embodiment of the present invention. Gas injector head 208 A- 1 is similar to gas injector head 208 A of FIG. 2 and only the significant differences are discussed below.

Gas injector head 208 A- 1 includes inner and outer body sections 1304 , 1306 , lip 1308 and mounting apertures 1310 as discussed above in reference to FIG. 13 .

Further, gas injector head 208 A- 1 includes an inner surface 250 and an outer surface 252 . Inner surface 250 is a concave vertical surface. Outer surface 252 is a vertical plane in accordance with this embodiment.

Gas injector ports 120 of gas injector head 208 A- 1 are formed in inner surface 250 . Gas injector intake ports 254 are formed in outer surface 252 .

Gas injector head 208 A- 1 includes gas injection channels 256 extending from and coupling gas injector intake ports 254 to gas injector ports 120 . In this embodiment, gas injection channels 256 are cylindrical apertures, sometimes called passageways, through gas injector head 208 A- 1 . Specifically, gas injector head 208 A- 1 includes five gas injection channels 256 , which lie in a common horizontal plane parallel to a principal surface 108 P of rotating susceptor 108 (see FIG. 1 ) and perpendicular outer surface 252 . Further, gas injection channels 256 are parallel to one another and are angled relative to inner surface 250 and outer surface 252 of gas injector head 208 A- 1 .

FIG. 15 is a front plan view of gas injector head 208 A- 1 along the line XV of FIG. 14 in accordance with one embodiment of the present invention. As shown in FIG. 15 , lip 1308 protrudes from inner body section 1304 .

FIGS. 16 , 17 , 18 , 19 and 20 are partial cross-sectional views of gas injector head 208 A- 1 taken along the lines XVI-XVI, XVII-XVII, XVIII-XVIII, XIX-XIX, XX-XX of FIG. 14 , respectively, in accordance with various embodiments of the present invention. Exemplary specifications for the various characteristics illustrated in FIGS. 16 , 17 , 18 , 19 , and 20 are set forth below in tables 11, 12, 13, 14, and 15, respectively.

FIG. 21 is a partial top cross-sectional view of a pancake reactor 2100 in accordance with one embodiment of the present invention. Pancake reactor 2100 of FIG. 21 is similar to pancake reactor of FIG. 1 and only the significant differences are discussed below and illustrated in FIG. 21 .

Referring now to FIG. 21 , pancake reactor 2100 includes gas injector heads 2108 A, 2108 B, 2108 C and 2108 D, collectively referred to as gas injector heads 2108 . In accordance with this embodiment, gas injector heads 2108 A, 2108 B, 2108 C and 2108 D each include a single gas injection channel 2156 A, 2156 B, 2156 C, and 2156 D, respectively. Gas injection channel 2156 A, 2156 B, 2156 C, 2156 D are slots extending through gas injector heads 2108 A, 2108 B, 2108 C and 2108 D.

To illustrate, gas injector head 2108 A includes an inner surface 2150 and an outer surface 2152 . Inner surface 2150 is a concave vertical surface. More particularly, inner surface 2150 is a segment of the cylindrical inner surface 106 I of chassis 130 (chassis 130 is shown in FIG. 1 ). Outer surface 2152 is a vertical plane in accordance with this embodiment.

A gas injector port 2120 of gas injector head 2108 A is formed in inner surface 2150 . A gas injector intake port 2154 is formed in outer surface 2152 .

Gas injector head 2108 A includes a single gas injection channel 2156 A extending from and coupling gas injector intake port 2154 to gas injector port 2120 . In this embodiment, gas injection channel 2156 A is a slot, sometimes called passageway, through gas injector head 2108 A. Although a single gas injection channel 2156 A is illustrated, more than one gas injection channel, i.e., a plurality of slots, is formed in gas injector head 2108 A in other embodiments.

The other gas injector heads 2108 B, 2108 C, 2108 D are similar to gas injector head 2108 A and so are not discussed in detail to avoid detracting from the principles of the invention.

In one embodiment, gas injection channels 2156 lie in a common horizontal plane parallel to a principal surface 108 P of rotating susceptor 108 and perpendicular to outer surface 2152 . However, in other embodiments, one or more or all of gas injection channels 2156 point up and/or down relative to principal surface 108 P of rotating susceptor 108 .

Generally, gas injection channels 2156 point across pancake reactor 2100 towards gas exhaust ports 122 . In a manner similar to that discussed above with regards to gas injector heads 208 , uniform flow of process gas through pancake reactor 2100 is achieved using gas injector heads 2108 .

In a manner similar to that discussed above with regards to gas injector head 208 B of FIG. 13 , gas injector heads 2108 includes inner body sections 1304 , outer body sections 1306 , and protruding lips 1308 . Further, outer body sections 1306 includes first and second mounting apertures 1310 A, 1310 B, collectively referred to as mounting apertures 1310 .

FIG. 22 is a partial top cross-sectional view of gas injector head 2108 A of FIG. 21 in accordance with one embodiment of the present invention. FIG. 23 is a front plan view of gas injector head 2108 A along the line XXIII of FIG. 22 in accordance with one embodiment of the present invention.

Referring now to FIGS. 22 and 23 together, gas injection channel 2156 A of gas injector head 2108 A has a width WA, a height HA and a length LA. Width WA is greater than height HA such that gas injection channel 2156 A is a slot extending through gas injector head 2108 A.

Further, as shown in FIG. 22 , width WA is uniform across length LA of gas injection channel 2156 A. Further, gas injection channel 2156 A is angled relative to inner surface 2150 and outer surface 2152 of gas injector head 2108 A. More particularly, vertical sidewalls 2202 A, 2202 B, collectively referred to as vertical sidewalls 2202 , of gas injector head 2108 A define width WA of gas injection channel 2156 A. Vertical sidewalls 2202 are angled relative to inner surface 2150 and outer surface 2152 of gas injector head 2108 A.

FIG. 24 is a partial top cross-sectional view of gas injector head 2108 B of pancake reactor 2100 of FIG. 21 in accordance with another embodiment of the present invention. FIG. 25 is a front plan view of gas injector head 2108 B along the line XXV of FIG. 24 in accordance with one embodiment of the present invention.

Referring now to FIGS. 24 and 25 together, gas injection channel 2156 B of gas injector head 2108 B has a first width WB 1 at outer surface 2152 of gas injector head 2108 B, a second width WB 2 at inner surface 2150 of gas injector head 2108 B, a height HB and a length LB. Widths WB 1 , WB 2 are greater than height HB such that gas injection channel 2156 B is a slot extending through gas injector head 2108 B.

Further, as shown in FIG. 24 , first width WB 1 at outer surface 2152 of gas injector head 2108 B is less than second width WB 2 at inner surface 2150 . Accordingly, the width of gas injection channel 2156 B increases across length LB from outer surface 2152 to inner surface 2150 of gas injection channel 2156 B. Thus, gas injection channel 2156 B of gas injector head 2108 B is a flared slot extending through gas injector head 2108 B.

Further, gas injection channel 2156 B is partially angled relative to outer surface 2152 of gas injector head 2108 B. More particularly, vertical sidewalls 2402 A, 2402 B of gas injector head 2108 B define the width of gas injection channel 2156 B. Vertical sidewall 2402 A is angled relative to outer surface 2152 of gas injector head 2108 B. Further, vertical sidewall 2402 B is perpendicular relative to outer surface 2152 of gas injector head 2108 B.

In the following tables, all dimensions are in inches unless otherwise noted. Exemplary specifications for the various characteristics illustrated in FIG. 3 are set forth below in table 1.

Exemplary specifications for the various characteristics illustrated in FIG. 4 are set forth below in table 2.

Exemplary specifications for the various characteristics illustrated in FIG. 5 are set forth below in table 3.

Exemplary specifications for the various characteristics illustrated in FIG. 6 are set forth below in table 4.

Exemplary specifications for the various characteristics illustrated in FIG. 7 are set forth below in table 5.

Exemplary specifications for the various characteristics illustrated in FIG. 9 are set forth below in table 6.

Exemplary specifications for the various characteristics illustrated in FIG. 10 are set forth below in table 7.

Exemplary specifications for the various characteristics illustrated in FIG. 11 are set forth below in table 8.

Exemplary specifications for the various characteristics illustrated in FIG. 14 are set forth below in table 9.

Exemplary specifications for the various characteristics illustrated in FIG. 15 are set forth below in table 10.

Exemplary specifications for the various characteristics illustrated in FIG. 16 are set forth below in table 11.

Exemplary specifications for the various characteristics illustrated in FIG. 17 are set forth below in table 12.

Exemplary specifications for the various characteristics illustrated in FIG. 18 are set forth below in table 13.

Exemplary specifications for the various characteristics illustrated in FIG. 19 are set forth below in table 14.

Exemplary specifications for the various characteristics illustrated in FIG. 20 are set forth below in table 15.

Exemplary specifications for the various characteristics illustrated in FIG. 22 are set forth below in table 16.

Exemplary specifications for the various characteristics illustrated in FIG. 23 are set forth below in table 17.

Exemplary specifications for the various characteristics illustrated in FIG. 24 are set forth below in table 18.

Exemplary specifications for the various characteristics illustrated in FIG. 25 are set forth below in table 19.

The drawings and the forgoing description gave examples of the present invention. The scope of the present invention, however, is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of the invention is at least as broad as given by the following claims.