Miniature light emitting diode device and manufacturing method thereof

Abstract

The invention relates to the field of semiconductor device manufacturing. The invention particularly relates to a miniature light-emitting diode device and a manufacturing method thereof. The micro light emitting diode device comprises a substrate; the N-type GaN layer is positioned on the substrate; the surface of the N-type GaN layer is divided into a P-type electrode region and an N-type electrode region; the light-emitting layer is located on the N-type GaN layer; the P-type GaN layer is located on the light-emitting layer; the insulated isolation groove is positioned between the P-type electrode region and the N-type electrode region, and is used for isolating the parts, positioned in the P-type electrode region, of the light-emitting layer and the P-type GaN layer from the parts, positioned in the N-type electrode region, of the light-emitting layer and the P-type GaN layer; an insulating spacer layer; the insulating spacer layer coats the light-emitting layer and the P-type GaN layer; wherein the part, located in the P-type electrode region, of the insulating spacer layer is as high as the part, located in the N-type electrode region. The miniature light-emitting diode device can effectively solve the problems that in the process of transferring from the manufacturing substrate to the driving substrate, the transferred device is prone to breakage and damage, and the yield is not ideal.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor device manufacturing, and in particular to a micro light emitting diode device and a manufacturing method thereof. Background Art

[0002] Micro light-emitting diode (Micro LED) display technology is a technology that miniaturizes and integrates light-emitting diodes (LEDs), that is, micron-scale LED devices are connected to a drive substrate to achieve precise control of the brightness of each device, thereby realizing image display. Currently, a major issue is that in the process of transferring devices from the manufacturing substrate to the drive substrate, the transferred devices are prone to cracking and damage, and the yield rate is not ideal.

[0003] Therefore, a solution is needed to reduce the damage that occurs during the transfer process, improve the yield of the product after transfer, and ensure product integrity. Summary of the invention

[0004] Therefore, the present invention provides a micro light emitting diode device and a manufacturing method thereof to solve the problem that the micro light emitting diode device is easily broken and damaged and has an unsatisfactory yield during the process of transferring the micro light emitting diode device from a manufacturing substrate to a driving substrate.

[0005] The present invention provides a micro light-emitting diode device, comprising: a substrate; an N-type GaN layer located on the substrate; the surface of the N-type GaN layer is divided into a P-type electrode area and an N-type electrode area; a light-emitting layer located on the N-type GaN layer; the light-emitting layer includes a portion located in the P-type electrode area and a portion located in the N-type electrode area; a P-type GaN layer located on the light-emitting layer; the P-type GaN layer includes a portion located in the P-type electrode area and a portion located in the N-type electrode area; an insulating isolation groove; the insulating isolation groove is located between the P-type electrode area and the N-type electrode area, separating the portion of the light-emitting layer located in the P-type electrode area and the N-type electrode area. The portion located in the N-type electrode area is isolated, and the portion of the P-type GaN layer located in the P-type electrode area is isolated from the portion located in the N-type electrode area; an insulating spacer layer; the insulating spacer layer covers the portion of the light-emitting layer located in the P-type electrode area and the portion of the P-type GaN layer located in the P-type electrode area, and at the same time covers the portion of the light-emitting layer located in the N-type electrode area and the portion of the P-type GaN layer located in the N-type electrode area; wherein the surface of the portion of the insulating spacer layer located in the P-type electrode area facing away from the substrate is equal in height to the surface of the portion located in the N-type electrode area facing away from the substrate.

[0006] Optionally, a projection of the light-emitting layer on the N-type GaN layer completely overlaps with a projection of the P-type GaN layer on the N-type GaN layer.

[0007] Optionally, the surface of the P-type GaN layer located in the P-type electrode region facing away from the substrate is at an equal height to the surface of the N-type electrode region facing away from the substrate; and the surface of the light-emitting layer located in the P-type electrode region facing away from the substrate is at an equal height to the surface of the N-type electrode region facing away from the substrate.

[0008] Optionally, the insulating isolation trench is in a straight line shape; or, the insulating isolation trench has a fold line shape with a bending portion toward the P-type electrode region; or, the insulating isolation trench has a fold line shape with a bending portion toward the N-type electrode region.

[0009] Optionally, the micro-light emitting diode device of the present invention further includes: a P-type electrode; the P-type electrode penetrates the insulating spacer layer to electrically connect to the P-type GaN layer; an N-type electrode; the N-type electrode penetrates the insulating spacer layer, the P-type GaN layer and the light-emitting layer to electrically connect to the N-type GaN layer; the surface of the P-type electrode facing away from the substrate is equal in height to the surface of the N-type electrode facing away from the substrate.

[0010] Optionally, the micro-light emitting diode device of the present invention further includes: a current spreading layer located on the P-type GaN layer; the current spreading layer is only located in the P-type electrode region; the projection of the current spreading layer on the N-type GaN layer is smaller than the projection of the P-type GaN layer on the N-type GaN layer; the portion of the insulating spacer layer located in the P-type electrode region also covers the current spreading layer; the P-type electrode passes through the insulating spacer layer and is in electrical contact with the current spreading layer.

[0011] The present invention also provides a method for manufacturing a micro light-emitting diode device, comprising the following steps: providing a substrate; forming an N-type GaN layer on the substrate; the surface of the N-type GaN layer is divided into a P-type electrode area and an N-type electrode area; forming a light-emitting layer on the N-type GaN layer; the light-emitting layer includes a portion located in the P-type electrode area and a portion located in the N-type electrode area; forming a P-type GaN layer on the light-emitting layer; the P-type GaN layer includes a portion located in the P-type electrode area and a portion located in the N-type electrode area; forming an insulating isolation groove; the insulating isolation groove is located between the P-type electrode area and the N-type electrode area, and the light-emitting layer is located in the P-type electrode area. The insulating spacer layer is formed by isolating the portion of the light-emitting layer located in the P-type electrode region and the portion of the P-type GaN layer located in the P-type electrode region, and isolating the portion of the P-type GaN layer located in the P-type electrode region and the portion of the N-type electrode region; and forming an insulating spacer layer; the insulating spacer layer covers the portion of the light-emitting layer located in the P-type electrode region and the portion of the P-type GaN layer located in the P-type electrode region, and at the same time covers the portion of the light-emitting layer located in the N-type electrode region and the portion of the P-type GaN layer located in the N-type electrode region; wherein the surface of the portion of the insulating spacer layer located in the P-type electrode region facing away from the substrate is at the same height as the surface of the portion located in the N-type electrode region facing away from the substrate.

[0012] Optionally, the steps of forming the light-emitting layer, forming the P-type GaN layer and forming the insulating isolation groove include: forming a light-emitting layer covering the entire surface of the N-type GaN layer; forming a P-type GaN layer covering the entire surface of the light-emitting layer; forming a first photoresist layer covering the entire surface on the side of the P-type GaN layer facing away from the substrate; patterning the first photoresist layer to form a patterned first photoresist layer; using the patterned first photoresist layer as a mask, etching the P-type GaN layer and the light-emitting layer to form an initial insulating isolation groove, exposing the surface of the N-type GaN layer, separating the P-type GaN layer into a portion located in the P-type electrode region and a portion located in the N-type electrode region, and separating the light-emitting layer into a portion located in the P-type electrode region and a portion located in the N-type electrode region; simultaneously etching the P-type GaN layer and the light-emitting layer in the N-type electrode region, etching an N-type electrode hole, and exposing the surface of the N-type GaN layer.

[0013] Optionally, the manufacturing method of the micro-light-emitting diode device of the present invention also includes: forming a third photoresist layer, the second photoresist layer covers a portion of the surface of the P-type GaN layer; patterning the third photoresist layer to form a patterned second photoresist layer; using the patterned third photoresist layer as a mask, etching the P-type GaN layer, the light-emitting layer and the N-type GaN layer to form a patterned P-type GaN layer, a patterned light-emitting layer and a patterned N-type GaN layer.

[0014] Optionally, the manufacturing method of the micro-light-emitting diode device of the present invention also includes: forming an insulating spacer layer, the insulating spacer layer covering the surface of the P-type GaN layer, the inner wall of the insulating isolation groove and the exposed surface of the N-type GaN layer; forming a fourth photoresist layer on the surface of the insulating spacer layer; patterning the fourth photoresist layer to form a patterned fourth photoresist layer; using the patterned fourth photoresist layer as a mask, etching the insulating spacer layer, etching a P-type electrode hole penetrating the insulating spacer layer in the P-type electrode region, exposing the surface of the film layer under the insulating spacer layer; etching through the insulating spacer layer at a position in the N-type electrode region corresponding to the N-type electrode hole, exposing the surface of the N-type GaN layer in the N-type electrode hole; the insulating spacer layer still covers the inner wall of the N-type electrode hole.

[0015] Optionally, the manufacturing method of the micro-light emitting diode device of the present invention also includes: forming a fifth photoresist layer on the surface of the insulating spacer layer; patterning the fifth photoresist layer to form a patterned fifth photoresist layer; the patterned fifth photoresist layer at least exposes the P-type electrode hole and the N-type electrode hole whose inner wall is covered by the insulating spacer layer; using the fifth photoresist layer as a mask, forming a P-type electrode on the surface of the insulating spacer layer located in the P-type electrode area, the P-type electrode fills the P-type electrode hole and is electrically in contact with the film layer under the insulating spacer layer; using the fifth photoresist layer as a mask, forming an N-type electrode on the surface of the insulating spacer layer located in the N-type electrode area, the N-type electrode fills the N-type electrode hole and is electrically in contact with the N-type GaN layer.

[0016] Optionally, the manufacturing method of the micro-light-emitting diode device of the present invention also includes: forming a current spreading layer covering the surface of the P-type GaN layer on the surface of the P-type GaN layer located in the P-type electrode area; forming a second photoresist layer on the surface of the current spreading layer; patterning the second photoresist layer to form a patterned second photoresist layer; etching the current spreading layer using the patterned second photoresist layer as a mask to form a patterned current spreading layer; the insulating spacer layer covers the current spreading layer, and the patterned current spreading layer is only located in the P-type electrode area; the P-type electrode hole exposes the surface of the patterned current spreading layer, and the P-type electrode electrically contacts the patterned current spreading layer.

[0017] The beneficial effects of the present invention are:

[0018] In the micro-light-emitting diode device provided by the present invention, the surface of the part of the insulating spacer layer located in the P-type electrode area facing away from the substrate substrate is equal in height to the surface of the part of the N-type electrode area facing away from the substrate substrate. Compared with the design in which only the N-type electrode is provided in the N-type electrode area, the present invention widens and strengthens the structure of the N-type electrode area by increasing the structure of the N-type electrode area to surround the N-type electrode, so that it is close to the structural composition of the P-type electrode area and has the same height size, so that when transferring from the manufacturing substrate to the driving substrate, the forces of the P-type electrode area and the N-type electrode area are basically balanced, and the tilt angle is small when falling, which greatly reduces the possibility of device damage. And due to the increase and enhancement of the structure of the N-type electrode area, the stress distribution is more even, and it is not easy to concentrate between the P-type electrode area and the N-type electrode area, so the possibility of device breakage is greatly reduced. Thereby ensuring the integrity of the product after transfer. In addition, the main light-emitting layer area is not changed, and no additional structural shielding is performed on it, so that the light-emitting effect of the improved device can be guaranteed.

[0019] The manufacturing method of the micro-light-emitting diode device provided by the present invention can manufacture the micro-light-emitting diode device of the present invention, and the surface of the part of the insulating spacer located in the P-type electrode area facing away from the substrate substrate is equal in height to the surface of the part of the N-type electrode area facing away from the substrate substrate. Compared with the design in which only the N-type electrode is provided in the N-type electrode area, the present invention widens and strengthens the structure of the N-type electrode area by increasing the structure of the N-type electrode area to surround the N-type electrode, so that it is close to the structural composition of the P-type electrode area, and the height size is the same, so that when transferring from the manufacturing substrate to the driving substrate, the forces of the P-type electrode area and the N-type electrode area are basically balanced, and the tilt angle is small when falling, which greatly reduces the possibility of device damage. And due to the increase and enhancement of the structure of the N-type electrode area, the stress distribution is more even, and it is not easy to concentrate between the P-type electrode area and the N-type electrode area, so the possibility of device breakage is greatly reduced. Thereby ensuring the integrity of the product after transfer. In addition, the main light-emitting layer area is not changed, and no additional structural shielding is performed on it, so that the light-emitting effect of the improved device can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a structural schematic diagram of a micro light emitting diode device;

[0022] Figure 2 A schematic diagram of a process of transferring a micro light emitting diode device from a manufacturing substrate to a driving substrate;

[0023] Figure 3 A schematic diagram of another process of transferring a micro light emitting diode device from a manufacturing substrate to a driving substrate;

[0024] Figure 4-Figure 16 A schematic diagram of various states in a preparation process of a micro-light emitting diode device according to an embodiment of the present invention;

[0025] Fig.16 A micro light emitting diode device according to an embodiment of the present invention;

[0026] Figure 17A-Figure 17C Schematic top views of the light-emitting layer and the P-type GaN layer of the micro-light-emitting diode device according to different embodiments of the present invention;

[0027] Fig.18 is a schematic structural diagram of a micro light emitting diode of a comparative example;

[0028] Fig.19 For a batch Figure 1 Optical microscope image of the micro-LED structure after transfer;

[0029] Fig. 20 For a batch Fig.16 Optical microscope image of the micro-LED structure after transfer.

[0030] Description of reference numerals:

[0031] 1-substrate substrate; 2-N-type GaN layer; 3-light-emitting layer; 4-P-type GaN layer; 5-current spreading layer; 6-P-type electrode; 7-N-type electrode; 8-insulating spacer layer; 9-first photoresist layer; 10-second photoresist layer; 11-third photoresist layer; 12-fourth photoresist layer; DETAILED DESCRIPTION

[0032] A structural reference for a micro light emitting diode device Figure 1, including: a substrate 1; an N-type GaN layer 2 located on the substrate; the surface of the N-type GaN layer 2 is divided into a P-type electrode area A and an N-type electrode area B; a light-emitting layer 3 located on the N-type GaN layer 2; the light-emitting layer 3 is only located in the P-type electrode area; a P-type GaN layer 4 located on the light-emitting layer 3; a current spreading layer 5 located on the P-type GaN layer; an insulating spacer layer 8 covering the above layers; a P-type electrode 6 that passes through the insulating spacer layer 8 and is in electrical contact with the current spreading layer, and an N-type electrode 7 that passes through the insulating spacer layer 8 and is in electrical contact with the N-type GaN layer. In such a structure, because the N-type electrode area only has an N-type electrode, and the insulating spacer layer is formed as a whole layer with the same thickness at any position, the height and width of the structure of the N-type electrode area except the electrode are much smaller than the P-type electrode area. Therefore, when using Figure 2 When laser ablation transfer is performed, the structure of the N-type electrode region B is much thinner than that of the P-type electrode region, so it will inevitably tilt more severely, which will easily cause damage. In addition, due to the protrusion of the P-type electrode and the N-type electrode, there is stress concentration between the P-type electrode region A and the N-type electrode region B, which is also prone to fracture.

[0033] Another transfer method in the prior art, such as Figure 3 As shown, during manufacturing, adhesive glue is first formed at the connection with the manufacturing substrate, and then the device structure is formed, that is, the device structure is inverted. Later, during transfer, the connecting glue is directly ablated, and the device is separated from the manufacturing substrate and transferred to the driving substrate. Although this method can make the device fall forward to the driving substrate, since the main structure is the same as the aforementioned structure, it is still easy to tilt when falling, and there is also the problem of stress concentration. It is also easy to break and fracture, but the location of the breakage is transferred to the bottom of the device, and the problem is still not solved.

[0034] In view of this, the present invention provides a micro light emitting diode device and a manufacturing method thereof to solve the problem that the micro light emitting diode device is easily broken and damaged and has an unsatisfactory yield during the process of transferring the micro light emitting diode device from a manufacturing substrate to a driving substrate.

[0035] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In the description of the present invention, it should be noted that the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0036] Example 1

[0037] refer to Fig.16, this embodiment provides a micro light emitting diode device, including:

[0038] Base substrate 1;

[0039] An N-type GaN layer 2 is located on a substrate 1; the surface of the N-type GaN layer 2 is divided into a P-type electrode region A and an N-type electrode region B;

[0040] A light emitting layer 3 located on the N-type GaN layer 2; the light emitting layer 3 includes a portion located in the P-type electrode region A and a portion located in the N-type electrode region B;

[0041] A P-type GaN layer 4 located on the light-emitting layer 3; the P-type GaN layer 4 includes a portion located in the P-type electrode region A and a portion located in the N-type electrode region B;

[0042] An insulating isolation groove (not numbered in the figure); the insulating isolation groove is located between the P-type electrode region A and the N-type electrode region B, isolating the portion of the light-emitting layer 3 located in the P-type electrode region A from the portion located in the N-type electrode region B, and isolating the portion of the P-type GaN layer 4 located in the P-type electrode region A from the portion located in the N-type electrode region B;

[0043] Insulating spacer layer 8; the insulating spacer layer 8 covers the portion of the light-emitting layer 3 located in the P-type electrode region A and the portion of the P-type GaN layer 4 located in the P-type electrode region A, and at the same time covers the portion of the light-emitting layer 3 located in the N-type electrode region B and the portion of the P-type GaN layer 4 located in the N-type electrode region B;

[0044] The surface of the insulating spacer layer 8 located in the P-type electrode region A facing away from the substrate 1 has the same height as the surface of the N-type electrode region B facing away from the substrate 1 .

[0045] In the micro-light-emitting diode device provided in this embodiment, the surface of the insulating spacer layer 8 located in the P-type electrode area A facing away from the substrate 1 is equal in height to the surface of the N-type electrode area B facing away from the substrate 1. Compared with the design in which only the N-type electrode 7 is provided in the N-type electrode area B, the present invention widens and strengthens the structure of the N-type electrode area B by increasing the structure of the N-type electrode area B to surround the N-type electrode 7, so that it is close to the structural composition of the P-type electrode area A, and the height size is the same, so that when transferring from the manufacturing substrate to the driving substrate, the forces of the P-type electrode area A and the N-type electrode area B are basically balanced, and the tilt angle is small when falling, which greatly reduces the possibility of device damage. And due to the increase and enhancement of the structure of the N-type electrode area, the stress distribution is more even, and it is not easy to concentrate between the P-type electrode area and the N-type electrode area, so the possibility of device breakage is greatly reduced. Thereby ensuring the integrity of the product after transfer.

[0046] In addition, the area of ​​the main light-emitting layer (i.e., the portion of the light-emitting layer 3 located in the P-type electrode region A) has not been changed, nor has it been shielded by additional structures, thereby ensuring the light-emitting effect of the improved device. Specifically, the portion of the light-emitting layer 3 and the P-type GaN layer 4 located in the N-type electrode region only serves to enhance the structure and does not emit light. The resistance between the N-type electrode 7 and the N-type GaN layer 2 is very small, and its effect on light emission is negligible; the resistance between the P-type electrode 6 and the P-type GaN layer 4 is very large, so a current expansion layer 5 is added between the P-type electrode 6 and the P-type GaN layer, and the resistance between the current expansion layer 5 and the two is very small, so the effect of electrode contact on resistance is reduced; at the same time, the light-emitting effect is more related to the area size of the light-emitting layer 3 and the P-type GaN layer 4, because the resistance of the light-emitting layer and the P-type GaN layer 4 is much larger than that of these two layers, so the change in the contact area between the current expansion layer 5 and the N-type electrode 7 has little effect on the overall resistance. In summary, the light-emitting area and the light-emitting effect are compared to Figure 1 The structure remains basically unchanged and will not be reduced.

[0047] Furthermore, the projection of the light emitting layer 3 on the N-type GaN layer 2 completely overlaps with the projection of the P-type GaN layer 4 on the N-type GaN layer 2 .

[0048] By setting the projections of the light-emitting layer 3 and the P-type GaN layer 4 on the N-type GaN layer 2 to completely overlap, the upper and lower structures are completely consistent, which is conducive to the uniform distribution of stress; and the overall strength of the structure is stronger than the different projections of the upper and lower structures, so that the overall strength of the device can be increased and the possibility of damage can be reduced.

[0049] Furthermore, the surface of the P-type GaN layer 4 located in the P-type electrode region A on the side facing away from the substrate 1 is equal in height to the surface of the P-type electrode region B on the side facing away from the substrate 1; and the surface of the light-emitting layer 3 located in the P-type electrode region A on the side facing away from the substrate 1 is equal in height to the surface of the N-type electrode region B on the side facing away from the substrate 1.

[0050] By setting the P-type GaN layer 4 and the light-emitting layer 3 in the P-type electrode area A and the N-type electrode area B to have equal heights respectively, the film layers in the P-type electrode area A and the N-type electrode area B are made equal, thereby improving the consistency of the structure in the two electrode areas, making the stress distribution more uniform, and further reducing the possibility of damage and fracture.

[0051] Further, in different embodiments, the insulating isolation groove is a straight line (refer to Fig. 17C ); or, the insulating isolation groove has a folded line shape toward the bending portion of the P-type electrode region (reference Fig.17A ); or, the insulating isolation groove has a folded line shape toward the bending portion of the N-type electrode region (reference Fig. 17B ). Through the design of different insulating isolation grooves, the structural ratio of the P-type electrode region A and the N-type electrode region B can be adjusted, thereby adjusting the stress distribution to reduce the stress concentration and the fracture of the inverted device.

[0052] Furthermore, the micro light emitting diode device of this embodiment further includes:

[0053] P-type electrode 6; the P-type electrode 6 penetrates the insulating spacer layer 8 and is electrically connected to the P-type GaN layer 4;

[0054] N-type electrode 7; the N-type electrode 7 penetrates the insulating spacer layer 8, the P-type GaN layer 4 and the light-emitting layer 3 and is electrically connected to the N-type GaN layer 2;

[0055] The surface of the P-type electrode 6 facing away from the substrate 1 is at the same height as the surface of the N-type electrode 7 facing away from the substrate 1 .

[0056] Setting the top surface heights of the P-type electrode 6 and the N-type electrode 7 to be equal can reduce the degree of tilt when the device is transferred and separated from the substrate, and the contact with the driving substrate is generally in a horizontal state, reducing the possibility of damage and increasing the uniformity of stress distribution.

[0057] Furthermore, the micro-light-emitting diode device of this embodiment also includes: a current spreading layer 5 located on the P-type GaN layer 4; the current spreading layer 5 is only located in the P-type electrode area A; the projection of the current spreading layer 5 on the N-type GaN layer 2 is smaller than the projection of the P-type GaN layer 4 on the N-type GaN layer 2; the insulating spacer layer 8 located in the P-type electrode area A also covers the current spreading layer 5; the P-type electrode 6 passes through the insulating spacer layer 8 and is in electrical contact with the current spreading layer 5.

[0058] By providing the current spreading layer 5 , the contact resistance between the P-type electrode 6 and the P-type GaN layer 4 can be reduced, thereby reducing the voltage of the light-emitting diode.

[0059] Example 2

[0060] refer to Figure 4-Figure 16 This embodiment provides a method for manufacturing a micro light emitting diode device, comprising the following steps:

[0061] Providing a substrate 1;

[0062] Forming an N-type GaN layer 2 on the base substrate 1;

[0063] The surface of the N-type GaN layer 2 is divided into a P-type electrode region A and an N-type electrode region B;

[0064] forming a light-emitting layer 3 on the N-type GaN layer 2; the light-emitting layer 3 includes a portion located in the P-type electrode region A and a portion located in the N-type electrode region B;

[0065] A P-type GaN layer 4 is formed on the light-emitting layer 3; the P-type GaN layer 4 includes a portion located in the P-type electrode region A and a portion located in the N-type electrode region B;

[0066] An insulating isolation groove (not shown in the figure) is formed; the insulating isolation groove is located between the P-type electrode region A and the N-type electrode region B, isolating the portion of the light-emitting layer 3 located in the P-type electrode region A from the portion located in the N-type electrode region B, and isolating the portion of the P-type GaN layer 4 located in the P-type electrode region A from the portion located in the N-type electrode region B;

[0067] An insulating spacer layer 8 is formed; the insulating spacer layer 8 covers the portion of the light-emitting layer 3 located in the P-type electrode region A and the portion of the P-type GaN layer 4 located in the P-type electrode region A, and at the same time covers the portion of the light-emitting layer 3 located in the N-type electrode region B and the portion of the P-type GaN layer 4 located in the N-type electrode region B;

[0068] The surface of the insulating spacer layer 8 located in the P-type electrode region A facing away from the substrate 1 has the same height as the surface of the N-type electrode region B facing away from the substrate 1 .

[0069] The manufacturing method of the micro-light-emitting diode device provided in this embodiment is suitable for manufacturing the micro-light-emitting diode device of the above-mentioned embodiment 1. The surface of the part of the insulating spacer layer 8 located in the P-type electrode area A facing away from the substrate substrate 1 is equal in height to the surface of the part of the N-type electrode area B facing away from the substrate substrate 1. Compared with the design in which only the N-type electrode 7 is provided in the N-type electrode area B, the present invention widens and strengthens the structure of the N-type electrode area B by increasing the structure of the N-type electrode area B to surround the N-type electrode 7, so that it is close to the structural composition of the P-type electrode area A, and the height size is the same, so that when transferring from the manufacturing substrate to the driving substrate, the forces of the P-type electrode area A and the N-type electrode area B are basically balanced, and the tilt angle is small when falling, which greatly reduces the possibility of device damage. And due to the increase and enhancement of the structure of the N-type electrode area, the stress distribution is more even, and it is not easy to concentrate in the middle of the P-type electrode area and the N-type electrode area, so the possibility of device breakage is greatly reduced. Thereby ensuring the integrity of the product after transfer.

[0070] In addition, the area of ​​the main light-emitting layer (i.e., the portion of the light-emitting layer 3 located in the P-type electrode region A) has not been changed, nor has it been shielded by additional structures, thereby ensuring the light-emitting effect of the improved device. In other words, the portion of the light-emitting layer 3 and the P-type GaN layer 4 located in the N-type electrode region only serves to enhance the structure and does not emit light. The resistance between the N-type electrode 7 and the N-type GaN layer 2 is very small, and its effect on light emission is negligible; the resistance between the P-type electrode 6 and the P-type GaN layer 4 is very large, so a current expansion layer 5 is added between the P-type electrode 6 and the P-type GaN layer, and the resistance between the current expansion layer 5 and the two is very small, so the effect of electrode contact on resistance is reduced; at the same time, the light-emitting effect is more related to the area size of the light-emitting layer 3 and the P-type GaN layer 4, because the resistance of the light-emitting layer and the P-type GaN layer 4 is much larger than that of these two layers, so the change in the contact area between the current expansion layer 5 and the N-type electrode 7 has little effect on the overall resistance. In summary, the light-emitting area and the light-emitting effect are compared to Figure 1 The structure remains basically unchanged and will not be reduced.

[0071] Furthermore, the steps of forming the light emitting layer, forming the P-type GaN layer and forming the insulating isolation groove include:

[0072] refer to Figure 4 , forming a light-emitting layer 3 covering the entire surface of the N-type GaN layer 2;

[0073] Also refer to Figure 4 , forming a P-type GaN layer 4 covering the entire surface of the light-emitting layer 3;

[0074] refer to Figure 5 In some embodiments, the present invention further includes: forming a current spreading layer 5 covering the surface of the P-type GaN layer 4 on the surface of the P-type electrode region A;

[0075] For further reference, Figure 6 and Figure 7 , forming a first photoresist layer 9 covering the entire surface on the side of the P-type GaN layer 4 facing away from the base substrate 1; patterning the first photoresist layer 9 to form a patterned first photoresist layer 9; using the patterned first photoresist layer 9 as a mask, etching the P-type GaN layer 4 and the light-emitting layer 3 to form an initial insulating isolation groove, exposing the surface of the N-type GaN layer 2, separating the P-type GaN layer 4 into a portion located in the P-type electrode region A and a portion located in the N-type electrode region B, and separating the light-emitting layer 3 into a portion located in the P-type electrode region A and a portion located in the N-type electrode region B; at the same time, etching the P-type GaN layer 4 and the light-emitting layer 3 in the N-type electrode region B, etching an N-type electrode hole, and exposing the surface of the N-type GaN layer 2.

[0076] When there is a current spreading layer 5 covering the P-type GaN layer 4 , the first photoresist layer 9 is formed on the surface of the current spreading layer 5 ; and the initial insulating isolation groove and the N-type electrode hole also penetrate the current spreading layer 5 during etching.

[0077] In this way, the light-emitting layer 3 and the P-type GaN layer in the P-type electrode region A and the N-type electrode region B are formed simultaneously in the same step, which can ensure that the corresponding film layer structures in the two regions are of equal height, thereby facilitating uniform stress dispersion and improving structural strength.

[0078] In a specific embodiment, the above steps include:

[0079] An epitaxial layer structure including an n-type GaN layer 2, a light-emitting layer 3, a p-type GaN layer 4, etc. is grown on a sapphire substrate by using MOCVD (metal organic chemical vapor deposition) or other epitaxial layer growth methods.

[0080] A current spreading layer 5 (usually a doped metal oxide such as ITO / GZO, etc., with a thickness of about 100 nm) is deposited on the p-type GaN layer 4 by magnetron sputtering, electron beam evaporation or other coating methods, and a rapid annealing device is used to form an ohmic contact with the p-type GaN.

[0081] Use fully automatic coating and developing equipment or other coating and display equipment to coat 2-3μm photoresist on the current spreading layer, and use a photolithography machine to expose the designated position; then use automatic coating and developing equipment to remove the unexposed photoresist to form a photolithography pattern; then use ICP etching equipment to etch (usually the etching depth is about 1.0μm) to form the corresponding structure, and then use a stripper to remove the residual photoresist.

[0082] In some embodiments, reference Figure 8 and Fig. 9 , and also includes: forming a second photoresist layer 10 on the surface of the current spreading layer 5; patterning the second photoresist layer 10 to form a patterned second photoresist layer 10; using the patterned second photoresist layer 10 as a mask, etching the current spreading layer 5 to form a patterned current spreading layer 5; the patterned current spreading layer 5 is only located in the P-type electrode area A.

[0083] In a specific embodiment, the above steps include:

[0084] Use fully automatic coating and developing equipment or other coating and display equipment to coat 2-3μm photoresist on the current spreading layer, and use a photolithography machine to expose the designated position; then use automatic coating and developing equipment to remove the unexposed photoresist to form a photolithography pattern; then use ICP etching equipment or chemical solution immersion to etch (usually the etching depth is the thickness of the current spreading layer) to form the corresponding structure, and then use a stripper to remove the residual photoresist.

[0085] For further reference, Fig.10 and Fig.11 , forming a third photoresist layer 11, wherein the third photoresist layer 11 covers a portion of the surface of the P-type GaN layer 4; patterning the third photoresist layer 11 to form a patterned third photoresist layer 11; using the patterned third photoresist layer 11 as a mask, etching the P-type GaN layer 4, the light-emitting layer 3 and the N-type GaN layer 2 to form a patterned P-type GaN layer, a patterned light-emitting layer and a patterned N-type GaN layer.

[0086] In a specific embodiment, the above steps include: using a fully automatic coating and developing device or other coating and display equipment to coat 7-9 μm photoresist on the current spreading layer, and using a photolithography machine to expose the designated position; then using an automatic coating and developing device to remove the unexposed photoresist to form a photolithography pattern, such as Figure 5 ; Then, ICP etching equipment is used (usually the etching depth is 5μm, that is, the thickness of the epitaxial layer) to form the corresponding structure, and then a stripper is used to remove the residual photoresist.

[0087] For further reference, Figure 12-14 , and also includes: forming an insulating spacer layer 8, wherein the insulating spacer layer 8 covers the surface of the P-type GaN layer 4, the inner wall of the insulating isolation groove and the exposed surface of the N-type GaN layer 2; when there is a patterned current spreading layer 5, the insulating spacer layer 8 also covers the patterned current spreading layer 5.

[0088] A fourth photoresist layer 12 is formed on the surface of the insulating spacer layer 8; the fourth photoresist layer 12 is patterned to form a patterned fourth photoresist layer 12; the insulating spacer layer 8 is etched using the patterned fourth photoresist layer 12 as a mask, and a P-type electrode hole penetrating the insulating spacer layer 8 is etched in the P-type electrode region A to expose the surface of the film layer under the insulating spacer layer 8 (when the current spreading layer 5 is present, the surface of the current spreading layer 5 is exposed; when the current spreading layer 5 is not present, the surface of the P-type GaN layer 4 is exposed); at a position in the N-type electrode region B corresponding to the N-type electrode hole, etching is performed to penetrate the insulating spacer layer 8 to expose the surface of the N-type GaN layer 2 in the N-type electrode hole; the insulating spacer layer 8 still covers the inner wall of the N-type electrode hole.

[0089] In a specific embodiment, the above steps include:

[0090] Use PECVD (plasma enhanced chemical vapor deposition equipment) or other deposition equipment (atomic layer deposition equipment) to deposit an insulating layer (usually silicon oxide, silicon nitride, aluminum oxide, etc., with a thickness of usually 200 to 250 nm).

[0091] Use fully automatic coating and developing equipment or other coating and display equipment to coat 1-2μm photoresist on the current spreading layer, and use a photolithography machine to expose the designated position; then use automatic coating and developing equipment to remove the unexposed photoresist to form a photolithography pattern; then use dry etching equipment (usually the etching depth is the thickness of the insulating layer) to form the corresponding structure, and then use a stripper to remove the residual photoresist.

[0092] For further reference, Fig.15 , Fig.16 , further comprising: forming a fifth photoresist layer 13 on the surface of the insulating spacer layer 8; patterning the fifth photoresist layer 13 to form a patterned fifth photoresist layer 13; the patterned fifth photoresist layer 13 at least exposes the P-type electrode hole and the N-type electrode hole whose inner wall is covered by the insulating spacer layer 8; using the fifth photoresist layer 13 as a mask, forming a P-type electrode 6 on the surface of the insulating spacer layer 8 located in the P-type electrode area A, the P-type electrode 6 filling the P-type electrode hole and electrically contacting the film layer under the insulating spacer layer 8 (when the current spreading layer 5 is present, the surface of the current spreading layer 5 is in contact; when the current spreading layer 5 is not present, the surface of the P-type GaN layer 4 is in contact); using the fifth photoresist layer 13 as a mask, forming an N-type electrode 7 on the surface of the insulating spacer layer 8 located in the N-type electrode area B, the N-type electrode 7 filling the N-type electrode hole and electrically contacting the N-type GaN layer 2.

[0093] In a specific embodiment, the above steps include:

[0094] Use fully automatic coating and developing equipment or other coating and display equipment to coat 3-4.5μm photoresist on the current spreading layer, and use a photolithography machine to expose the designated position; then use automatic coating and developing equipment to remove the unexposed photoresist to form a photolithography pattern; then use electron beam evaporation or thermal evaporation coating or magnetron sputtering to plate p / n-type electrodes (usually materials such as Cr, Ti, Pt, Au and other multi-layer structures, with a total thickness of about 0.7μm); finally, use metal stripping and de-bonding processes to remove the photoresist and the metal on the photoresist to form the corresponding structure.

[0095] In order to demonstrate the effect of the micro-LED provided by the present invention on reducing breakage and fracture, some embodiments and comparative examples are provided below for comparison. Specifically:

[0096] Example 3

[0097] The micro-LED device of the above embodiment 1 is manufactured by the manufacturing method of the above embodiment 2, wherein the insulating isolation groove has a folded line shape toward the bending portion of the P-type electrode region A (refer to Fig.17A ).

[0098] Example 4

[0099] The micro-LED device of the above embodiment 1 is manufactured by the manufacturing method of the above embodiment 2, wherein the insulating isolation groove has a folded line shape toward the bending portion of the N-type electrode region B (refer to Fig. 17B ).

[0100] Example 5

[0101] The micro-LED device of the above embodiment 1 is manufactured by the manufacturing method of the above embodiment 2, wherein the insulating isolation groove is a straight line (refer to Fig. 17C ).

[0102] Comparative Example 1

[0103] use Figure 1 The N-type electrode region B is not provided with a same-layer structure of the light-emitting layer 3 and the P-type GaN, and the portion of the insulating spacer layer 8 located in the N-type electrode region B is located on the surface of the N-type GaN layer 2.

[0104] Comparative Example 2

[0105] refer to Fig.18 , which is different from the device structure of Example 1 in that the light emitting layer 3, the P-type GaN layer 4 and the current spreading layer 5 extend to the N-type electrode region B, and no insulating isolation groove is provided to separate the two electrode regions.

[0106] For the micro-LED devices of the above-mentioned embodiments and comparative examples, a number of (>20) are selected after batch production and used Figure 2 The transfer from the manufacturing substrate (base substrate 1) to the driving substrate is carried out in the following manner. The results after the transfer are as follows:

[0107] Table 1 Comparison of results after transfer between different embodiments and comparative examples

[0108] project Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Broken crystal ratio 0 0 0.96％ 34％ 0

[0109] It can be seen from the above table that, by adopting the solution of this embodiment, the proportion of broken crystals after transfer is basically close to 0, and can be achieved to 0 by adjusting the insulating isolation groove. Figure 1 The structural scheme has a crystal fragmentation ratio of up to 34% and a very low yield. This shows that the scheme of the present invention can effectively improve the problem that in the process of transferring micro-light-emitting diode devices from the manufacturing substrate to the driving substrate, the transferred devices are prone to breakage and damage, and the yield is not ideal. For Comparative Example 2, although the effect of a crystal fragmentation rate of 0 can also be achieved, the areas of the P-type GaN layer 4 and the light-emitting layer 3 are both increased, and the current density per unit area is reduced at the same current, resulting in a decrease in luminous efficiency. Therefore, the provision of an insulating isolation groove is necessary.

[0110] In addition, reference Fig.19 and Fig. 20 ,contrast Figure 1 The structure and Fig.16 The optical microscope image after structure transfer also shows Figure 1 The structural damage rate is quite high, and some of them have poor luminous effect although the structure is basically intact. The yield rate is only close to 50%. Fig.16 The structure of the present invention is completely free of damage, and the luminous effect is good, with a yield of 100%. It can be seen that the solution of the present invention can effectively improve the problem that the micro-LED device is easily broken and damaged during the transfer from the manufacturing substrate to the driving substrate, and the yield is not ideal. Of course, in actual mass production, it is still inevitable that broken crystals will occur, but compared with Figure 1 The yield of the structure is close to 50%, which is a great improvement.

[0111] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A micro light emitting diode device, characterized in that: include: substrate substrate; An N-type GaN layer located on a substrate; a surface of the N-type GaN layer is divided into a P-type electrode region and an N-type electrode region; A light-emitting layer located on the N-type GaN layer; the light-emitting layer includes a portion located in the P-type electrode region and a portion located in the N-type electrode region; A P-type GaN layer located on the light-emitting layer; the P-type GaN layer includes a portion located in the P-type electrode region and a portion located in the N-type electrode region; Insulation isolation slot; The insulating isolation groove is located between the P-type electrode region and the N-type electrode region, isolating a portion of the light-emitting layer located in the P-type electrode region from a portion located in the N-type electrode region, and isolating a portion of the P-type GaN layer located in the P-type electrode region from a portion located in the N-type electrode region; Insulating spacer; The insulating spacer layer covers the portion of the light-emitting layer located in the P-type electrode region and the portion of the P-type GaN layer located in the P-type electrode region, and simultaneously covers the portion of the light-emitting layer located in the N-type electrode region and the portion of the P-type GaN layer located in the N-type electrode region; The surface of the insulating spacer layer located in the P-type electrode region facing away from the substrate has the same height as the surface of the insulating spacer layer located in the N-type electrode region facing away from the substrate.

2. The micro light emitting diode device according to claim 1, characterized in that: The projection of the light-emitting layer on the N-type GaN layer completely overlaps with the projection of the P-type GaN layer on the N-type GaN layer.

3. The micro light emitting diode device according to claim 2, characterized in that: The surface of the P-type GaN layer located in the P-type electrode region facing away from the substrate is at the same height as the surface of the N-type electrode region facing away from the substrate; and, The surface of the portion of the light emitting layer located in the P-type electrode region facing away from the substrate is at the same height as the surface of the portion of the light emitting layer located in the N-type electrode region facing away from the substrate.

4. The micro light emitting diode device according to claim 2, characterized in that: The insulating isolation groove is in a straight line shape; Alternatively, the insulating isolation groove has a zigzag shape with a bent portion toward the P-type electrode region; Alternatively, the insulating isolation trench has a zigzag shape with a bent portion toward the N-type electrode region.

5. The micro light emitting diode device according to claim 1, characterized in that: Also includes: A P-type electrode; the P-type electrode penetrates the insulating spacer layer and is electrically connected to the P-type GaN layer; N-type electrode; The N-type electrode penetrates the insulating spacer layer, the P-type GaN layer and the light-emitting layer and is electrically connected to the N-type GaN layer; The surface of the P-type electrode facing away from the substrate is at the same height as the surface of the N-type electrode facing away from the substrate.

6. The micro light emitting diode device according to claim 5, characterized in that: Also includes: A current spreading layer located on the P-type GaN layer; The current spreading layer is only located in the P-type electrode region; The projection of the current spreading layer on the N-type GaN layer is smaller than the projection of the P-type GaN layer on the N-type GaN layer; The portion of the insulating spacer layer located in the P-type electrode region also covers the current spreading layer; The P-type electrode penetrates the insulating spacer layer and is in electrical contact with the current spreading layer.

7. A method for manufacturing a micro light emitting diode device, characterized in that: The following steps are involved: providing a substrate base plate; An N-type GaN layer is formed on the substrate; the surface of the N-type GaN layer is divided into a P-type electrode area and an N-type electrode area; forming a light-emitting layer on the N-type GaN layer; the light-emitting layer includes a portion located in the P-type electrode region and a portion located in the N-type electrode region; forming a P-type GaN layer on the light-emitting layer; the P-type GaN layer includes a portion located in the P-type electrode region and a portion located in the N-type electrode region; An insulating isolation groove is formed; the insulating isolation groove is located between the P-type electrode region and the N-type electrode region, isolating a portion of the light-emitting layer located in the P-type electrode region from a portion located in the N-type electrode region, and isolating a portion of the P-type GaN layer located in the P-type electrode region from a portion located in the N-type electrode region; forming an insulating spacer layer; The insulating spacer layer covers the portion of the light-emitting layer located in the P-type electrode region and the portion of the P-type GaN layer located in the P-type electrode region, and simultaneously covers the portion of the light-emitting layer located in the N-type electrode region and the portion of the P-type GaN layer located in the N-type electrode region; The surface of the insulating spacer layer located in the P-type electrode region facing away from the substrate has the same height as the surface of the insulating spacer layer located in the N-type electrode region facing away from the substrate.

8. The method for manufacturing a micro light emitting diode device according to claim 7, characterized in that: The steps of forming the light emitting layer, forming the P-type GaN layer and forming the insulating isolation groove include: forming a light-emitting layer covering the entire surface of the N-type GaN layer; Forming a P-type GaN layer covering the entire surface of the light-emitting layer; Forming a first photoresist layer covering the entire surface of the P-type GaN layer on the side facing away from the substrate; patterning the first photoresist layer to form a patterned first photoresist layer; Using the patterned first photoresist layer as a mask, etching the P-type GaN layer and the light-emitting layer to form an initial insulating isolation groove, exposing the surface of the N-type GaN layer, separating the P-type GaN layer into a portion located in a P-type electrode region and a portion located in an N-type electrode region, and separating the light-emitting layer into a portion located in a P-type electrode region and a portion located in an N-type electrode region; At the same time, the P-type GaN layer and the light-emitting layer are etched in the N-type electrode region to form an N-type electrode hole, thereby exposing the surface of the N-type GaN layer.

9. The method for manufacturing a micro light emitting diode device according to claim 8, characterized in that: Also includes: forming a third photoresist layer, wherein the third photoresist layer covers a portion of the surface of the P-type GaN layer; Patterning the third photoresist layer to form a patterned third photoresist layer; The P-type GaN layer, the light-emitting layer and the N-type GaN layer are etched using the patterned third photoresist layer as a mask to form a patterned P-type GaN layer, a patterned light-emitting layer and a patterned N-type GaN layer.

10. The method for manufacturing a micro light emitting diode device according to claim 8, characterized in that: Also includes: forming an insulating spacer layer, wherein the insulating spacer layer covers the surface of the P-type GaN layer, the inner wall of the insulating isolation groove and the exposed surface of the N-type GaN layer; forming a fourth photoresist layer on the surface of the insulating spacer layer; patterning the fourth photoresist layer to form a patterned fourth photoresist layer; Using the patterned fourth photoresist layer as a mask, the insulating spacer layer is etched, and a P-type electrode hole penetrating the insulating spacer layer is etched in the P-type electrode region to expose the surface of the film layer under the insulating spacer layer; at a position in the N-type electrode region corresponding to the N-type electrode hole, the insulating spacer layer is etched to expose the surface of the N-type GaN layer in the N-type electrode hole; the insulating spacer layer still covers the inner wall of the N-type electrode hole.

11. The method for manufacturing a micro light emitting diode device according to claim 10, characterized in that: Also includes: forming a fifth photoresist layer on the surface of the insulating spacer layer; patterning the fifth photoresist layer to form a patterned fifth photoresist layer; The patterned fifth photoresist layer at least exposes the P-type electrode hole and the N-type electrode hole whose inner wall is covered by the insulating spacer layer; Using the fifth photoresist layer as a mask, forming a P-type electrode on the surface of the insulating spacer layer located in the P-type electrode region, wherein the P-type electrode fills the P-type electrode hole and is in electrical contact with the film layer below the insulating spacer layer; Using the fifth photoresist layer as a mask, an N-type electrode is formed on the surface of the insulating spacer layer located in the N-type electrode region, and the N-type electrode fills the N-type electrode hole and electrically contacts the N-type GaN layer.

12. The method for manufacturing a micro light emitting diode device according to claim 11, characterized in that: Also includes: On the surface of the P-type GaN layer located in the P-type electrode region, a current spreading layer is formed covering the surface of the P-type GaN layer; forming a second photoresist layer on the surface of the current spreading layer; Patterning the second photoresist layer to form a patterned second photoresist layer; Using the patterned second photoresist layer as a mask, etching the current spreading layer to form a patterned current spreading layer, wherein the patterned current spreading layer is only located in the P-type electrode region; The insulating spacer layer covers the patterned current spreading layer; The P-type electrode hole exposes the surface of the current spreading layer, and the P-type electrode electrically contacts the patterned current spreading layer.

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