Structure with micro device

This application claims the priority benefits of U.S. provisional application Ser. No. 62/607,325, filed on Dec. 19, 2017 and Taiwan application serial no. 107119258, filed on Jun. 5, 2018. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.

The invention relates to a semiconductor structure, and more particularly, to a structure with micro device.

At present, transferring micro light-emitting diodes (LEDs) from a carrier to a receiving substrate is mainly done via an electrostatic force or a magnetic force. In general, micro LEDs are held by holding structures, so that it is easier for the micro LEDs to be picked up from the substrate, transported and transferred to be placed on the receiving substrate, and the micro LEDs are secured by the holding structures to prevent the quality of the micro LEDs from being affected by external factors during the substrate-transfer process. However, positions where the holding structures are disposed on the micro LEDs may influence a transportation and transfer yield of the micro LEDs. Therefore, how to allow the holding structures to temporarily hold the micro LEDs for the micro LEDs to be transported and transferred between the substrate and the receiving substrate more easily and efficiently has become an important subject in the industry.

The invention provides a structure with micro device capable of effectively improving a transportation and transfer yield of micro devices.

A structure with micro device of the invention includes a substrate, a plurality of micro devices, and a plurality of holding structures. The micro devices are disposed on the substrate and arranged in a plurality of rows. Each of the micro devices has a top surface. The holding structures are respectively disposed on the top surface of each of the micro devices and extend to the substrate. Distances between the holding structure on the micro devices on any one of the rows and the holding structures on the micro devices on two adjacent rows are different.

In an embodiment of the invention, each of the micro devices includes a first-type electrode and a second-type electrode, the first-type electrode or the second-type electrode is located on the top surface, and the holding structures are away from the first-type electrodes or the second-type electrodes.

In an embodiment of the invention, orthographic projections of the holding structures on the substrate overlap an orthographic projection of a gravity center of each of the micro devices on the substrate.

In an embodiment of the invention, there is a distance between the holding structures and a center of the top surface of each of the micro devices.

In an embodiment of the invention, wherein the holding structures overlaps the center of the top surface of each of the micro devices.

In an embodiment of the invention, wherein there is a distance between the orthographic projection of each of the holding structures on the substrate and the orthographic projection of a center of each of the micro devices on the substrate.

In an embodiment of the invention, the first-type electrodes or the second-type electrodes of the micro devices on two adjacent rows are adjacent to each other, and a ratio of a first distance between the adjacent holding structures corresponding to the second-type electrodes on two adjacent rows to a second distance between the adjacent holding structures corresponding to the first-type electrodes on two adjacent rows is less than 1 and greater than or equal to 0.6.

In an embodiment of the invention, each of the holding structures includes at least one holding portion, the holding portion is located on an edge of each of the micro devices, and a ratio of a width of the holding portion on the edge to a side length of the edge is between 0.01 and 0.6.

In an embodiment of the invention, the at least one holding portion includes a plurality of holding portions and the holding portions are separated from each other.

In an embodiment of the invention, a minimal distance between an orthographic projection of each of the holding portions on the substrate and the orthographic projection of the center of each of the micro devices on the substrate is the same.

In an embodiment of the invention, a minimal distance between each of the holding portions and a center of the top surface of each of the micro devices is the same.

In an embodiment of the invention, the minimal distance between the center of the top surface of each of the micro devices and each of the holding structures is less than or equal to ½ of a minimal side length of the top surface.

In an embodiment of the invention, there is a maximal distance between the holding portion and the corresponding edge of the top surface, and a ratio of the maximal distance to the side length of the corresponding edge of the micro device is less than or equal to 0.2.

In an embodiment of the invention, the structure with micro device further includes a plurality of buffer structures. The bufferstructures are disposed between the holding structures and the substrate. The holding structures are connected to the substrate through the buffer structures, and the material of the buffer structures is different from the material of the holding structures.

In an embodiment of the invention, within a unit area, a ratio of an orthographic projection area of the buffer structures on the substrate to an orthographic projection area of the holding structure on the substrate is between 0.2 and 0.9.

In an embodiment of the invention, the buffer structures are away from each of the micro devices.

In an embodiment of the invention, orthographic projections of the buffer structures on the substrate are separated from the orthographic projection of each of the micro devices on the substrate by a minimal distance, and the minimal distance is less than or equal to 10 μm.

In an embodiment of the invention, intervals between the micro devices on any one of the rows and the micro devices on two adjacent rows are the same.

In an embodiment of the invention, the holding structure on the micro devices on each of the rows has a symmetric centerline, and distances between the symmetric centerline on any one of the rows and the symmetric centerlines on two adjacent rows are different.

To sum up, in the design of the structure with micro device of the invention, the micro devices are disposed on the substrate and arranged in multiple rows, and the holding structures are respectively disposed on the top surface of each of the micro devices, wherein the distances between the holding structure on any one of the micro devices and the holding structures on the micro devices on two adjacent rows are different. With this design, not only the process margin can be increased, but also the micro devices, when being transported and transferred between different substrates to be applied to a display with micro device, can be provided with preferable fixing, supporting and connection via the holding structures, so as to average the force when the micro devices are grabbed.

To make the above features and advantages of the invention more comprehensible, embodiments accompanied with drawings are described in detail below.

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

FIG. 1A is a schematic top view of a structure with micro device according to an embodiment of the invention.

FIG. 1B is a schematic cross-sectional view of the structure with micro device depicted in FIG. 1A .

FIG. 1C is a schematic top view of a structure with micro device according to another embodiment of the invention.

FIG. 2A and FIG. 2B are schematic top views of a structure with micro device according to several embodiments of the invention.

FIG. 2C is a magnified schematic view of an area R of FIG. 2B .

FIG. 2D is a schematic top view of a structure with micro device according to an embodiment of the invention.

FIG. 3A and FIG. 3G are schematic cross-sectional views of a structure with micro device according to several embodiments of the invention.

FIG. 4A and FIG. 4B are schematic cross-sectional views of a structure with micro device according to a plurality of embodiments of the invention.

The embodiments of the invention describe a structure of micro devices (e.g., micro light emitting diodes (LEDs) and microchips) which are ready to be picked up and transferred to a circuit substrate. For example, a receiving substrate may be a display substrate, a light-emitting substrate, a substrate having functional devices, such as transistors or integrated circuits (ICs) or a substrate having metal redistribution lines, which is not limited in the invention. Even though some of the embodiments of the invention are specific to describe micro LEDs including p-n diodes, it should be understood that the embodiments of the invention are not limited thereto, and some of the embodiments may also be applied to other micro semiconductor devices. Those devices may be designed according to such manner to control execution of a predetermined electron function (e.g., diode, transistor, integrated circuit) or photon function (e.g., LED, laser). FIG. 1A is a schematic top view of a structure with micro device according to an embodiment of the invention. FIG. 1B is a schematic cross-sectional view of the structure with micro device depicted in FIG. 1A . It should be mentioned that FIG. 1B is illustrated along a line I-I′ in FIG. 1A . Referring to FIG. 1A and FIG. 1B simultaneously, a structure with micro device 100 a provided in the present embodiment includes a substrate 120 , a plurality of micro devices 140 a (schematically illustrated as multiple micro devices in FIG. 1A ) and a plurality of holding structures 160 a 1 , 160 a 2 and 160 a 3 (which are schematically illustrated as three holding structures in FIG. 1A ). The micro devices 140 a are disposed on the substrate 120 and arranged in a plurality of rows C 1 , C 2 and C 3 (which are schematically illustrated as three rows in FIG. 1A ). Each of the micro devices 140 a has a top surface 141 a . In this case, each of the rows C 1 , C 2 and C 3 is arranged along an X-axial direction, but the invention is not limited thereto, and in other embodiments, is may be applicable in the same way as if each of the rows C 1 , C 2 and C 3 is arranged along the same direction. The holding structures 160 a 1 , 160 a 2 and 160 a 3 are disposed on the substrate 120 . The holding structures 160 a 1 , 160 a 2 and 160 a 3 are respectively disposed on the top surface 141 a of each of the micro devices 140 a and extend to the substrate 120 . Specially, distances between one of the holding structures 160 a 1 , 160 a 2 and 160 a 3 on the micro devices 140 a on any one of the rows and the others of the holding structures 160 a 1 , 160 a 2 and 160 a 3 on the micro devices 140 a on two adjacent rows are different.

Specifically, the substrate 120 is a temporary substrate which is capable of being fixed and has a flat surface, for example, a plastic substrate, a glass substrate or a sapphire substrate, but the invention is not limited thereto. Referring to again to FIG. 1A , by viewing from the top, the micro devices 140 a are arranged with an interval L 1 on the rows C 1 , C 2 and C 3 , an interval L 2 is between the micro devices 140 a arranged on the row C 1 and the micro devices 140 a arranged on the row C 2 , and the interval L 2 is between the micro devices 140 a arranged on the row C 2 and the the micro devices 140 a arranged on the row C 3 , wherein the intervals L 1 and L 2 may be the same to achieve a preferable process yield. In embodiments that are not shown, the intervals L 1 and L 2 may be different, which is not particularly limited in invention. It should be specially noted that in the present embodiment, the intervals L 2 between the micro devices 140 a on any one of the rows C 1 , C 2 and C 3 and the micro device on adjacent two of the rows C 1 , C 2 and C 3 are the same, and the intervals L 1 between two adjacent micro devices 140 a on any one of the rows C 1 , C 2 and C 3 are the same. In this case, the micro devices 140 a are, for example, micro light emitting diodes (LEDs), and a maximum size of each of the micro devices 140 a is less than or equal to 100 μm, such that the micro devices 140 a may be subsequently transferred, integrated and assembled to a heterogeneous integration system which includes displays having substrates in various sizes. In other embodiments, the micro devices may also be micro integrated circuits (ICs), micro laser diodes (LDs) or micro sensors, which are not particularly limited in invention. In the present embodiment, the micro devices 140 a are embodied as horizontal-type micro devices, for example, horizontal-type micro LEDs. Each of the micro devices 140 a includes a first-type electrode 144 a and a second-type electrode 145 a , wherein the first-type electrodes 144 a are located on the top surfaces 141 a , and the holding structures 160 a 1 , 160 a 2 and 160 a 3 are far away from the first-type electrodes 144 . In other words, the first-type electrodes 144 a are located on the top surfaces 141 a , and the holding structures 160 a 1 , 160 a 2 and 160 a 3 do not directly contact the first-type electrodes 144 , but the invention is not limited thereto. In other embodiments that are not shown, it may also be the second-type electrodes being located on the top surfaces, and the holding structures do not directly contact the second-type electrodes. The first-type electrodes 144 a and the second-type electrode 145 a have opposite electrical properties. In the present embodiment, the first-type electrodes 144 a are, for example, P-type electrodes, and the second-type electrodes 145 a are, for example, N-type electrodes. However, in other embodiments, the first-type electrodes 144 a may also be N-type electrodes, and the second-type electrodes 145 a may also be P-type electrodes, which is not particularly limited in invention. It should be noted that the top surface 141 a of each of the micro devices 140 a refers to a surface corresponding to a position of a light-emitting layer 146 a of each of the micro devices 140 a.

Referring again to FIG. 1A , the top surface 141 a of each of the micro devices 140 a has four edges SD 1 , SD 2 , SD 3 and SD 4 , wherein the edges SD 1 and SD 2 are disposed opposite to each other, and the edges SD 3 and SD 4 are disposed opposite to each other. It should be mentioned that a contour of each of the micro devices 140 a of the present embodiment is embodied as a rectangular shape in the top view, but the invention is not limited thereto. In other embodiments that are not shown, the contour of each of the micro devices in the top view may be other adaptive shapes, such as a square shape, a circular shape or a trapezoidal shape.

Furthermore, as illustrated in FIG. 1A and FIG. 1B , each of the holding structures 160 a 1 , 160 a 2 and 160 a 3 of the present embodiment directly and continuously covers the top surface 141 a of each of the micro devices 140 a on the rows C 1 , C 2 and C 3 . In other embodiments, each of the holding structures 160 a 1 , 160 a 2 and 160 a 3 may also discontinuously cover the top surface 141 a of each of the micro devices 140 a on the rows C 1 , C 2 and C 3 . Specially, the holding structure 160 a 1 on the row C 1 , the holding structure 160 a 2 on the row C 2 and the holding structure 160 a 3 on the row C 3 are separated from one another, but the invention is not limited thereto. In addition, a part of the holding structure 160 a 2 is disposed on the substrate 120 , and another part of the holding structure 160 a 2 is disposed on the micro devices 140 a . Within a unit area U, an orthographic projection area of the holding structure 160 a 2 on the substrate 120 is greater than an orthographic projection area of the micro devices 140 a on the substrate 120 , thereby achieving a more preferable holding effect.

In the present embodiment, the second-type electrodes 145 a of the micro devices 140 a arranged on the row C 1 and the second-type electrodes 145 a of the micro devices 140 a arranged on the row C 2 are adjacent to each other, and the first-type electrodes 144 a of the micro devices 140 a arranged on the row C 2 and the first-type electrodes 144 a of the micro devices 140 a arranged on the row C 3 are adjacent to each other. The distance between the holding structure 160 a 1 on the row C 1 and the holding structure 160 a 2 on the row C 2 is greater than the distance between the holding structure 160 a 2 on the row C 2 and the holding structure 160 a 3 on the row C 3 . Furthermore, there is a first distance L 3 between the holding structure 160 a 1 on the row C 1 and the holding structure 160 a 2 on the row C 2 , there is a second distance L 4 between the holding structure 160 a 2 on the row C 2 and the holding structure 160 a 3 on the row C 3 , and the first distance L 3 is greater than the second distance L 4 . For instance, the holding structure 160 a 1 on the top surfaces 141 a of the micro devices 140 a on the row C 1 has a symmetric centerline S 1 , the holding structure 160 a 2 on the top surfaces 141 a of the micro devices 140 a on the row C 2 has a symmetric centerline S 2 , and the holding structure 160 a 3 on the top surfaces 141 a of the micro devices 140 a on the row C 3 has a symmetric centerline S 3 . The first distance L 3 is the distance between the symmetric centerline S 1 on the row C 1 and the symmetric centerline S 2 on the row C 2 , and the second distance L 4 is the distance between the symmetric centerline S 2 on the row C 2 and the symmetric centerline S 3 on the row C 3 . In other embodiments, the first distance L 3 and the second distance L 4 may also be defined by other identical comparison bases of the holding structures 160 a 1 , 160 a 2 and 160 a 3 on the top surfaces 141 a of the micro devices 140 a , which may be, for example, selected from distances between the centers on the edges SD 3 of the holding structures 160 a 1 , 160 a 2 and 160 a 3 on the top surfaces 141 a of the micro devices 140 a , or selected from minimal distances between the holding structures 160 a 1 , 160 a 2 and 160 a 3 of the micro devices 140 a by viewing from the top, but the invention is not limited thereto. Preferably, a ratio of the second distance L 4 to the first distance L 3 is, for example, less than 1 and greater than or equal to 0.6. It should be mentioned that in the present embodiment, the first-type electrodes 144 a and the second-type electrodes 145 a of the micro devices 140 a are disposed in different directions on the odd rows (i.e., the rows C 1 and C 3 ) and the even row (i.e., the row C 2 ), such that distances between gravity centers P of the micro devices 140 a on the odd rows (i.e., the rows C 1 and C 3 ) and a gravity center P of the micro devices 140 a on the even row (i.e., the row C 2 ) are also different. Through the distances between the holding structures 160 a 1 , 160 a 2 and 160 a 3 on the micro devices 140 a on the rows being different from each other, a transfer process may be more stable, thereby increasing a transfer yield. It should be specially mentioned that a width D 1 of each of the holding structures 160 a 1 , 160 a 2 and 160 a 3 is gradually reduced from the centers of the top surfaces 141 a toward the corresponding edges SD 3 and SD 4 of the top surfaces 141 a , such that the holding structures 160 a 1 , 160 a 2 and 160 a 3 may have maximal contact areas on the top surfaces 141 a and have minimal contract areas on the corresponding edges SD 3 and SD 4 . Thereby, the holding structures 160 a 1 , 160 a 2 and 160 a 3 may have preferable fixing strength for being easily picked up in the subsequent transfer process. In other embodiments, in a structure with micro device 100 b illustrated in FIG. 2A , a width D 2 of each of the holding structures 160 b 1 , 160 b 2 and 160 b 3 is gradually increased from the centers of the top surfaces 141 a toward the corresponding edges SD 3 and SD 4 of the top surfaces 141 a , thereby preventing the holding structures 160 a 1 , 160 a 2 and 160 a 3 from directly contacting the first-type electrodes 144 a or the second-type electrodes 145 a during a manufacturing process to increase a process margin.

In addition, the orthographic projections of the holding structures 160 a 1 , 160 a 2 and 160 a 3 on the substrate 120 overlap an orthographic projection of the gravity center P of each of the micro devices 140 a on the substrate 120 . It should be noted that the holding structures 160 a 1 , 160 a 2 and 160 a 3 being disposed on the gravity centers of the micro devices 140 a , the micro devices 140 a , when being transported and transferred between different transfer substrates, may be provided with not only preferable fixing, supporting and connection via the holding structures 160 a 1 , 160 a 2 and 160 a 3 , but also provided with an average force to grab the micro devices 140 a , thereby preventing an issue of an uneven grabbing force. It should be noted that there is a distance F between each of the holding structures 160 a 1 , 160 a 2 and 160 a 3 of the present embodiment and a center A of the top surface 141 a of each of the micro devices 140 a , namely, the two do not overlap with each other and an extension direction of each of the holding structures 160 a 1 , 160 a 2 and 160 a 3 does not pass through the center A of the top surface 141 a of each of the micro devices 140 a , such that the holding structures 160 a 1 , 160 a 2 and 160 a 3 may be disposed collectively on the gravity centers P of the micro devices 140 a . The center A in this case refers to a geometric center of each of the top surfaces 141 a.

It should be mentioned that the holding structures 160 a 1 , 160 a 2 and 160 a 3 of the structure with micro device 100 a of the present embodiment do not overlap the center A of the top surface 141 a of each of the micro devices 140 a . However, in another embodiment, referring to FIG. 1C , holding structures 160 a ′ 1 , 160 a ′ 2 and 160 a ′ 3 of a structure with micro device 100 a ′ may also overlap the center A of the top surface 141 a of each of the micro devices 140 a , and it still pertains to the scope sought for protection by the invention as long as the holding structures 160 a ′ 1 , 160 a ′ 2 and 160 a ′ 3 are disposed collectively on the gravity centers P of the micro devices 140 a . In addition, an orthographic projection of each of the holding structures 160 a ′ 1 , 160 a ′ 2 and 160 a ′ 3 on the substrate 120 and an orthographic projection of a center B of each of the micro devices 140 a on the substrate 120 do not overlap with each other and have a distance F 1 therebetween, such that the holding structures 160 a ′ 1 , 160 a ′ 2 and 160 a ′ 3 may be disposed more collectively on the gravity centers P of the micro devices 140 a.

Referring to FIG. 2B to FIG. 2C simultaneously, FIG. 2C is a magnified schematic view of an area R of FIG. 2B . In the present embodiment, a holding structure 160 c 1 includes a plurality of holding portions 162 c 1 , each of the holding portions 162 c 1 is disposed on the edges SD 3 and SD 4 , wherein a ratio of a width W 3 of each of the holding portions 162 c 1 on the edges SD 3 and SD 4 to a side length W 2 of the corresponding edges SD 3 and SD 4 may be, for example, between 0.01 and 0.6. When the ratio is less than 0.01, it represents an insufficient holding force, and when the ratio is greater than 0.6, it represents that the subsequent pick-up and transfer process may be affected. In this case, the holding portions 162 c 1 are separated from each other and respectively located on the edges SD 3 and SD 4 which are opposite to each other on each of the micro devices 140 a on the row C 1 . In other embodiments, the holding portions may also be continuously and simultaneously disposed on the edges SD 3 and SD 4 which are opposite to each other, but the invention is not limited thereto. In the same way, a holding structure 160 c 2 has a plurality of holding portions 162 c 2 , and the holding portions 162 c 2 are separated from each other and respectively located on the edges SD 3 and SD 4 which are opposite to each other on each of the micro devices 140 a on the row C 2 . A holding structure 160 c 3 has a plurality of holding portions 162 c 3 , and the holding portions 162 c 3 are separated from each other and respectively located on the edges SD 3 and SD 4 which are opposite to each other on each of the micro devices 140 a on the row C 3 . In this case, each of extension directions of the holding portions 162 c 1 , 162 c 2 and 162 c 3 of the holding structures 160 c 1 , 160 c 2 and 160 c 3 passes through a center of the two edges SD 3 and SD 4 on the top surface 141 a of each of the micro devices 140 a on the rows C 1 , C 2 and C 3 . Specially, orthographic projections of the holding portions 162 c 1 , 162 c 2 and 162 c 3 of the holding structures 160 c 1 , 160 c 2 and 160 c 3 on the substrate 120 do not overlap an orthographic projection of the center B of each of the micro devices 140 a on the substrate 120 .

Taking the holding portion 162 c 1 of the holding structure 160 c 1 as an example for description, the extension direction between the holding portions 162 c 1 passes the center of the two edges SD 3 and SD 4 of the top surface 141 a of each of the micro devices 140 a , i.e., passes through the center A of the top surface 141 a . Minimal distances L 5 and L 6 between orthographic projections of the holding portions 162 c 1 on the edges SD 3 and SD 4 which are opposite to each other on each of the micro devices 140 a on the substrate 120 and the orthographic projection of the center B of each of the micro devices 140 a on the substrate 120 are the same. Minimal distances L 7 and L 8 between the holding portions 162 c 1 on the edges SD 3 and SD 4 which are opposite to each other on each of the micro devices 140 a and the center A of the top surface 141 a of each of the micro devices 140 a are the same. The minimal distances L 7 and L 8 between the center A of the top surface 141 a of each of the micro devices 140 a and the holding portions 162 c 1 on the edges SD 3 and SD 4 which are opposite to each other on each of the micro devices 140 a are smaller than ½ of a minimal side length W 1 of the top surface 141 a . In this case, W 1 is, for example, less than or equal to 50 μm, and L 7 and L 8 are, for example, less than 20 μm, but the invention is not limited thereto. There are maximal distances L 9 and L 10 between the holding portions 162 c 1 and the edges SD 3 and SD 4 of the corresponding top surfaces 141 a , and a ratio of the maximal distances L 9 and 10 to the side length W 2 of the two edges SD 3 and SD 4 of the corresponding micro device 141 a is less than or equal to 0.2. The maximal distances L 9 and L 10 are, for example, less than or equal to 20 μm, and if the maximal distance is greater than 20 μm, it increases the difficulty in the pick-up process. It should be specially mentioned that the holding structures 160 c 1 , 160 c 2 and 160 c 3 illustrated in FIG. 2B are symmetrically disposed on the top surface 141 a of each of the micro devices 140 a , thereby providing a preferable subsequent transfer yield.

In brief, in a structure with micro device 100 c of the present embodiment, with the holding structures 160 c 1 , 160 c 2 and 160 C 3 disposed on the top surfaces 141 a of the micro devices 140 a and the extension directions of the holding structures 160 c 1 , 160 c 2 and 160 c 3 passing through the center A of the top surface 141 a of each of the micro devices 140 a , the micro devices 140 a , when being transported and transferred between different transfer substrates, may be provided with not only preferable fixing, supporting and connection via the holding structures 160 c 1 , 160 c 2 and 160 c 3 , but also provided with an average force to grab the micro devices 140 a , thereby preventing an issue of an uneven grabbing force.

It should be noted that in the present embodiment, the holding structure 160 c 1 on the row C 1 , the holding structure 160 c 2 on the row C 2 and the holding structure 160 c 3 on the row C 3 are separated from one another, but the invention is not limited thereto. However, in another embodiment, referring to FIG. 2D , in a structure with micro device 100 d , a holding structure 160 d 1 on the row C 1 , a holding structure 160 d 2 on the row C 2 and a holding structure 160 d 3 on the row C 3 may also be connected together, which still falls within the scope sought for protection by the invention.

In addition, referring again to FIG. 1B , each of the micro devices 140 a further includes a bottom surface 142 a opposite to the top surface 141 a and a peripheral surface 143 a connected with the top surface 141 a and the bottom surface 142 a . In the present embodiment, the structure with micro device 100 a may further selectively include a plurality of buffer structures 180 a 1 and 180 a 2 , wherein the buffer structures 180 a 1 and 180 a 2 are disposed between the holding structure 160 a 1 (or the holding structure 160 a 2 or 160 a 3 ) and the substrate 120 and directly contact the holding structure 160 a 1 (or the holding structure 160 a 2 or 160 a 3 ). Namely, the holding structure 160 a 1 (or the holding structure 160 a 2 or 160 a 3 ) of the present embodiment does not directly contact the substrate 120 and is connected to the substrate 120 through the buffer structures 180 a 1 and 180 a 2 . In this case, referring to FIG. 1A , an orthographic projection of the holding structure 160 a 1 (or the holding structure 160 a 2 or 160 a 3 ) on the substrate 120 overlaps orthographic projections of the buffer structures 180 a 1 and 180 a 2 on the substrate 120 .

In the present embodiment, the holding structure 160 a 1 (or the holding structure 160 a 2 or 160 a 3 ) is made of a material different from a material of the buffer structures 180 a 1 and 180 a 2 , and a Young's modulus of the holding structure 160 a 1 (or the holding structure 160 a 2 or 160 a 3 ) is greater than that of the buffer structures 180 a 1 and 180 a 2 . Thus, the buffer structures 180 a 1 and 180 a 2 are capable of buffering. In this case, the holding structure 160 a 1 (or the holding structure 160 a 2 or 160 a 3 ) is made of, for example, an inorganic material, and the buffer structures 180 a 1 and 180 a 2 are made of, for example, an organic material. In this case, the buffer structures 180 a 1 and 180 a 2 are far away from the micro devices 140 a , i.e., the buffer structures 180 a 1 and 180 a 2 do not directly contact the micro devices 140 a . Referring to FIG. 1A , the orthographic projections of the buffer structures 180 a 1 and 180 a 2 on the substrate 120 may not overlap the orthographic projections of the micro devices 140 a on the substrate 120 . Within the unit area U, a ratio of an orthographic projection area of the buffer structures 180 a 1 and 180 a 2 on the substrate 120 to an orthographic projection area of the holding structure 160 a 1 (or the holding structure 160 a 2 or 160 a 3 ) on the substrate 120 is between 0.2 and 0.9. In brief, the buffer structures 180 a 1 and 180 a 2 of the present embodiment does not directly contact the micro devices 140 a , and thus, the buffer structures 180 a 1 and 180 a 2 may not only absorb affection by external forces during the process of transporting and transferring the micro devices 140 a held by the holding structure 160 a 1 (or the holding structure 160 a 2 or 160 a 3 ) to improve the transportation and transfer yield, but also not affect the pick-up yield of the micro devices 140 a.

To be more specific, the orthographic projections of the buffer structures 180 a 1 and 180 a 2 on the substrate 120 are separated from the orthographic projections of the micro devices 140 a on the substrate 120 by a minimal distance H, and preferably, the minimal distance H is less than or equal to 10 μm. Referring to FIG. 1B , there may be an air gap G 1 among the holding structure 160 a 1 (or the holding structure 160 a 2 or 160 a 3 ), the substrate 120 and the buffer structures 180 a 1 and 180 a 2 . In addition, a vertical distance between the micro devices 140 a and the substrate 120 is, for example, between 0.1 μm and 5 μm. In the present embodiment, an area of the buffer structures 180 a 1 and 180 a 2 contacting the holding structure 160 a 1 (or the holding structure 160 a 2 or 160 a 3 ) is greater than an area of the buffer structures 180 a 1 and 180 a 2 contacting the micro devices 140 a.

In brief, in the design of the structure with micro device 100 a of the present embodiment, the micro devices 140 a are arranged on the rows C 1 , C 2 and C 3 on the substrate 120 , and the holding structures 160 a 1 , 160 a 2 and 160 a 3 are respectively disposed on the top surface 141 a of each of the micro devices 140 a , and the distances L 3 and L 4 between one of the holding structures (e.g., the holding structure 160 a 2 ) on the micro devices 140 a on any one of the rows (e.g., the row C 2 ) and the other two of the holding structures (e.g., the holding structures 160 a 1 and 160 a 3 ) on the micro devices 140 a on two adjacent rows (e.g., the rows C 1 and C 3 ) are different. In this way, when the micro devices 140 a are transported and transferred between different transfer substrates, they may be provided with preferable fixing, supporting and connection via the holding structures 160 a 1 , 160 a 2 and 160 a 3 , so as to average the force when the micro devices 140 a are grabbed.

It should be noted that the reference numerals and a part of the contents in the previous embodiment are used in the following embodiments, in which identical reference numerals indicate identical or similar components, and repeated description of the same technical contents is omitted. The description related to the omitted parts can be found in the previous embodiment, and no repeated description is contained in the following embodiments.

FIG. 3A is a schematic cross-sectional view of a structure with micro device according to another embodiment of the invention. Referring to FIG. 1B and FIG. 3A simultaneously, a structure with micro device 100 e of the present embodiment is similar to the structure with micro device 100 a illustrated in FIG. 1B , and a difference therebetween lies in that: the structure with micro device 100 e of the present embodiment does not have any buffer structure, wherein a holding structure 160 e directly contacts the substrate 120 , and the holding structure 160 e directly contacts a peripheral surface 143 e of a micro device 140 e . In this case, there is an air gap G among the micro device 140 e , the holding structure 160 e and the substrate 120 . In addition, a cross-sectional shape of the micro device 140 e of the present embodiment is, for example, a rectangular shape, but the invention is not limited thereto.

FIG. 3B is a schematic cross-sectional view of a structure with micro device according to another embodiment of the invention. Referring to FIG. 3A and FIG. 3B simultaneously, a structure with micro device 100 f of the present embodiment is similar to the structure with micro device 100 e illustrated in FIG. 3A , and a difference therebetween lies in that: a holding structure 160 f of the structure with micro device 100 f of the present embodiment does not directly contact the peripheral surface 143 e of the micro device 140 e.

FIG. 3C is a schematic cross-sectional view of a structure with micro device according to another embodiment of the invention. Referring to FIG. 3A and FIG. 3C simultaneously, a structure with micro device 100 g of the present embodiment is similar to the structure with micro device 100 e illustrated in FIG. 3A , and a difference therebetween lies in that: a holding structure 160 g of the structure with micro device 100 g of the present embodiment further extends to cover a part of a bottom surface 142 e of the micro device 140 e . In addition, the structure with micro device 100 g of the present embodiment further includes a buffer layer 190 , wherein the buffer layer 190 is disposed between the bottom surface 142 e of the micro device 140 e and the substrate 120 and directly contacts the holding structure 160 g and the micro device 140 e . In other words, there is no air gap among the micro device 140 e , the holding structure 160 g and the substrate 120 in the present embodiment. In this case, the buffer layer 190 may absorb a stress generated when the micro device 140 e is bonded to the substrate 120 , thereby increasing a bonding yield. In other words, the buffer layer 190 may provide a stress buffering effect between the micro device 140 e and the substrate 120 . Preferably, a Young's modulus of the buffer layer 190 is less than that of the holding structure 160 g . In this case, the buffer layer 190 is made of a foaming material or an organic polymer material, such that the buffer layer 190 has a plurality of irregular air holes, wherein a porosity rate of the buffer layer 190 made of the foaming material may be greater than or equal to 50%, thereby providing a preferable buffering effect.

FIG. 3D is a schematic cross-sectional view of a structure with micro device according to another embodiment of the invention. Referring to FIG. 3A and FIG. 3D simultaneously, a structure with micro device 100 h of the present embodiment is similar to the structure with micro device 100 g illustrated in FIG. 3C , and a difference therebetween lies in that: the structure with micro device 100 h of the present embodiment is not provided with any buffer layer, and thus, there is an air gap G 1 among the micro device 140 e , a holding structure 160 h and the substrate 120 .

FIG. 3E is a schematic cross-sectional view of a structure with micro device according to another embodiment of the invention. Referring to FIG. 3A and FIG. 3E simultaneously, a structure with micro device 100 i of the present embodiment is similar to the structure with micro device 100 e illustrated in FIG. 3A , and a difference therebetween lies in that: a holding structure 160 i of the present embodiment totally covers the peripheral surface 143 e of the micro device 140 e , and there is an air gap G 2 among the micro device 140 e , the holding structure 160 i and the substrate 120 .

FIG. 3F is a schematic cross-sectional view of a structure with micro device according to another embodiment of the invention. Referring to FIG. 3A and FIG. 3F simultaneously, a structure with micro device 100 j of the present embodiment is similar to the structure with micro device 100 e illustrated in FIG. 3A , and a difference therebetween lies in that: a holding structure 160 j of the present embodiment does not totally cover the peripheral surface 143 e of the micro device 140 e . Namely, the holding structure 160 j merely covers a part of the peripheral surface 143 e of a micro device 140 e.

FIG. 3G is a schematic cross-sectional view of a structure with micro device according to another embodiment of the invention. Referring to FIG. 3A and FIG. 3G simultaneously, a structure with micro device 100 k of the present embodiment is similar to the structure with micro device 100 e illustrated in FIG. 3A , and a difference therebetween lies in that: holding portions 162 k of a holding structure 160 k of the present embodiment do not pass through a center of a width of a top surface 141 e of the micro device 140 e . Namely, only a part of the holding structure 160 k covers the top surface 141 e to cover the peripheral surface 143 e and extend to cover the substrate 120 .

FIG. 4A is a schematic cross-sectional view of a structure with micro device according to another embodiment of the invention. Referring to FIG. 3A and FIG. 4A simultaneously, a structure with micro device 100 m of the present embodiment is similar to the structure with micro device 100 e illustrated in FIG. 3A , and a difference therebetween lies in that: the structure with micro device 100 m includes a plurality of micro devices 140 m 1 and 140 m 2 , wherein the two adjacent micro devices 140 m 1 and 140 m 2 are connected to each other through a holding structure 160 m.

FIG. 4B is a schematic cross-sectional view of a structure with micro device according to another embodiment of the invention. Referring to FIG. 4A and FIG. 4B simultaneously, a structure with micro device 100 n of the present embodiment is similar to the structure with micro device 100 m illustrated in FIG. 4A , and a difference therebetween lies in that: the structure with micro device 100 n of the present embodiment further includes a plurality of buffer structures 180 n 1 and 180 n 2 , wherein holding portions 162 n of a holding structure 160 n are respectively connected to the substrate 120 through the buffer structures 180 n 1 and 180 n 2 , and two adjacent micro devices 140 n 1 and 140 n 2 are connected to each other through the holding portions 162 n of the holding structure 160 n . In this case, the holding portions 162 n do not pass through centers of widths of top surfaces 141 n 1 and 141 n 2 of the micro devices 140 n 1 and 140 n 2 , but the invention is not limited thereto.

Based on the above, in the design of the structure with micro device of the invention, the micro devices are disposed on the substrate and arranged in multiple rows, and the holding structures are respectively disposed on the top surface of each of the micro devices and extend to cover the substrate. The distances between the holding structure on any one of the micro devices and the holding structures on the micro devices on two adjacent rows are different. With this design, in addition to the process margin being increased, the micro devices, when being transported and transferred between different substrates, can be provided with preferable fixing, supporting and connection via the holding structures, so as to average the force when the micro devices are grabbed.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.