Light emitting device and method for manufacturing the same

Abstract

The present application relates to the field of semiconductor technology, and specifically discloses a light-emitting device and a manufacturing method thereof, wherein the light-emitting device comprises a substrate and a plurality of epitaxial layers formed on the substrate by epitaxial growth, wherein a plurality of artificial micro-pits are arranged in the light-emitting device, wherein the artificial micro-pits use at least one epitaxial layer in the substrate and / or the plurality of epitaxial layers as a stop layer, and extend to a subsequent epitaxial layer subsequently formed on the stop layer, wherein the first cross-sectional shape of the artificial micro-pit on a first reference plane parallel to the substrate is a non-regular hexagon or a regular hexagon. By the above method, the shape and size of the artificial micro-pits are flexibly controllable, thereby achieving the optimization of the hole injection effect of the artificial micro-pits.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, in particular to a light emitting device and a method for manufacturing the same. Background Art

[0002] Light-emitting diode (LED) is a photoelectric device that converts electrical energy into light energy and is widely used in lighting, backlighting and display. At present, the third-generation semiconductor nitride LED has a dislocation density of 10 9 / cm 2 The mainstream explanation for this phenomenon is that the multi-quantum well (MQW) in the V-shaped pits is thinner and has a lower In content than the MQW in the terrace area, so it has a wider bandgap and can form a potential barrier near the dislocation to prevent carriers from being captured.

[0003] The inventors of the present application have discovered in the long-term research and development process that the principle of naturally formed V-shaped pits is that the temperature of the superlattice growth layer is low, and the lateral epitaxy ability of nitrides (such as GaN) is poor, and at this time, penetrating dislocations will form V-shaped pits. The growth position of the above-mentioned naturally formed V-shaped pits is limited, and the growth mode of each V-shaped pit is also limited to growing around the dislocation. Therefore, the spatial position of the V-shaped pits is determined by the dislocations and is basically randomly distributed, resulting in the inability to optimize the hole injection effect of the V-shaped pits under the influence of dislocations, and the control of the shape and size of the V-shaped pits is difficult, and the risk of leakage current is increased, affecting the reliability of the light-emitting device.

[0004] Therefore, it is necessary to design an artificial micro-pit with flexible and controllable shape and size. Summary of the invention

[0005] The technical problem to be solved by the present application is to provide a light-emitting device and a method for manufacturing the same, so that the shape and size of the artificial micro-pits can be flexibly controlled, thereby optimizing the hole injection effect of the artificial micro-pits.

[0006] On the one hand, the present application provides a light-emitting device, which includes a substrate and a plurality of epitaxial layers stacked on the substrate by epitaxial growth. A plurality of artificial micro-pits are arranged in the light-emitting device. The artificial micro-pits use the substrate and / or at least one epitaxial layer in the plurality of epitaxial layers as a termination layer and extend into a subsequent epitaxial layer subsequently formed on the termination layer, wherein a first cross-sectional shape of the artificial micro-pits on a first reference plane parallel to the substrate is a non-regular hexagon or a regular hexagon.

[0007] On the other hand, the present application provides a method for manufacturing a light-emitting device, the method comprising: providing a substrate; using the substrate and / or at least one epitaxial layer on the substrate as a stop layer, and forming a starting micro-pit in the stop layer; continuing to grow subsequent epitaxial layers on the stop layer, so that under the induction of the starting micro-pit, an induced micro-pit is formed in the subsequent epitaxial layer as the subsequent epitaxial layer grows epitaxially, wherein the starting micro-pit forms an opening on the surface of the stop layer on one side facing the subsequent epitaxial layer, and the first cross-sectional shape of the opening on a first reference plane parallel to the substrate is a non-regular hexagon or a regular hexagon, and the size of the opening is set so that the cross-sectional shape of the induced micro-pit on the first reference plane parallel to the substrate is consistent with the cross-sectional shape of the opening on the first reference plane parallel to the substrate.

[0008] On the other hand, the present application provides a method for manufacturing a light-emitting device, the method comprising: providing a substrate; forming a plurality of epitaxial layers by stacking them on the substrate in an epitaxial growth manner; using the substrate and / or at least one of the plurality of epitaxial layers as a stop layer; etching a subsequent epitaxial layer subsequently formed on the stop layer from a side of the subsequent epitaxial layer facing away from the substrate to form a plurality of artificial micro-pits, wherein a first cross-sectional shape of the artificial micro-pits on a first reference plane parallel to the substrate is a non-regular hexagon or a regular hexagon.

[0009] The beneficial effect of the present application is that, different from the prior art, the artificial micro-pits of the present application use a substrate and / or at least one epitaxial layer in the multiple epitaxial layers as a stop layer, and extend to a subsequent epitaxial layer subsequently formed on the stop layer, that is, the present application can break through the limiting factors of the existing "artificial V-shaped pits" and select any substrate and / or epitaxial layer as the stop layer of the artificial micro-pits. Therefore, the spatial position of the artificial micro-pits of the present application is no longer simply determined by dislocations, but the artificial micro-pits extending to the subsequent epitaxial layer subsequently formed on the stop layer have a first cross-sectional shape on a first reference plane parallel to the substrate that is a non-regular hexagon or a regular hexagon, that is, the shape of the artificial micro-pits is no longer limited to a hexagonal pyramid, and the shape and size of the artificial micro-pits are flexibly controllable, thereby optimizing the hole injection effect of the artificial micro-pits. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0011] Figure 1 is a schematic structural diagram of a light-emitting device provided in the first embodiment of the present application;

[0012] Figure 2is a schematic structural diagram of a light-emitting device provided in a second embodiment of the present application;

[0013] Figure 3 is a schematic structural diagram of a light-emitting device provided in the third embodiment of the present application;

[0014] Figure 4 is a schematic structural diagram of a light-emitting device provided in a fourth embodiment of the present application;

[0015] Figure 5 is a schematic structural diagram of a light-emitting device provided in a fifth embodiment of the present application;

[0016] Figure 6 is a schematic flow chart of a method for manufacturing a light-emitting device provided in a sixth embodiment of the present application;

[0017] Figure 7 It is a schematic flow chart of a method for manufacturing a light-emitting device provided in the seventh embodiment of the present application. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0019] like Figures 1 to 5 As shown, the embodiment of the present application provides a light emitting device 100, which includes: a substrate 101 and multiple epitaxial layers. The multiple epitaxial layers are stacked on the substrate 101 by epitaxial growth.

[0020] A plurality of artificial micro-pits are arranged in the light-emitting device 100, wherein the artificial micro-pits use the substrate 101 and / or at least one of the multiple epitaxial layers as a stop layer and extend into a subsequent epitaxial layer subsequently formed on the stop layer, wherein the artificial micro-pits have a first cross-sectional shape on a first reference plane parallel to the substrate 101 that is a non-regular hexagon or a regular hexagon.

[0021] Specifically, the material of the substrate 101 includes, but is not limited to, at least one of sapphire, Si, SiC, GaN, ZnO, InP, and GaAs.

[0022] The multilayer epitaxial layer may include a first conductive type semiconductor layer 103 (e.g., an N-type GaN layer 103), a quantum well active layer 105 (e.g., a multi-quantum well active (MQW) layer 105 or a superlattice quantum well active layer) and a second conductive type semiconductor layer 107 (e.g., a P-type GaN layer 107) stacked in sequence on a substrate 101.

[0023] Furthermore, the material system of the quantum well active layer 105 includes: Al x1 In y1 Ga z1 N x2 P y2 As z2 , where 0≤x1 or y1 or z1 or x2 or y2 or z2≤1, optionally, x1+y1+z1=1, x2+y2+z2=1.

[0024] Furthermore, the multi-layer epitaxial layer may include a buffer layer 102, a first conductive type semiconductor layer 103, a pre-well preparation layer 104, a quantum well active layer 105, an electron blocking layer 106, a second conductive type semiconductor layer 107 or a second conductive type heavily doped semiconductor layer stacked in sequence on the substrate 101.

[0025] The artificial micro-pits may use at least one of the first conductive type semiconductor layer 103, the quantum well active layer 105 and the second conductive type semiconductor layer 107 and / or the substrate 101 as a stop layer, and extend into a subsequent epitaxial layer subsequently formed on the stop layer.

[0026] For example, the artificial micro-pits use the first conductive type semiconductor layer 103 as a stop layer and extend into the quantum well active layer 105 and the second conductive type semiconductor layer 107 subsequently formed on the first conductive type semiconductor layer 103 .

[0027] For another example, the artificial micro-pits use the first conductive type semiconductor layer 103 as a stop layer and extend into the quantum well active layer 105 subsequently formed on the first conductive type semiconductor layer 103. At this time, the quantum well active layer 105 is used as a stop layer again and extends into the second conductive type semiconductor layer 107 subsequently formed on the quantum well active layer 105.

[0028] For another example, the artificial micro-pits use the substrate 101 as a stop layer and extend into the first conductive type semiconductor layer 103 , the quantum well active layer 105 , and the second conductive type semiconductor layer 107 that are subsequently formed on the substrate 101 .

[0029] For another example, the artificial micro-pits use the substrate 101 as a stop layer and extend into a first conductive type semiconductor layer 103 subsequently formed on the substrate 101, and then use the first conductive type semiconductor layer 103 as a stop layer and extend into a quantum well active layer 105 and a second conductive type semiconductor layer 107 subsequently formed on the first conductive type semiconductor layer 103.

[0030] For another example, the artificial micro-pits use the substrate 101 as a stop layer and extend into a first conductive type semiconductor layer 103 subsequently formed on the substrate 101, and then use the first conductive type semiconductor layer 103 as a stop layer and extend into a quantum well active layer 105 subsequently formed on the first conductive type semiconductor layer 103, and then use the quantum well active layer 105 as a stop layer and extend into a second conductive type semiconductor layer 107 subsequently formed on the quantum well active layer 105.

[0031] Different from the prior art, the artificial micro-pit of the present application uses the substrate 101 and / or at least one epitaxial layer in the multiple epitaxial layers as a stop layer, and extends to the subsequent epitaxial layer subsequently formed on the stop layer, that is, the present application can break through the limiting factors of the existing "artificial V-shaped pit" and select any substrate 101 and / or epitaxial layer as the stop layer of the artificial micro-pit. Therefore, the spatial position of the artificial micro-pit of the present application is no longer simply determined by the dislocation, but extends to the artificial micro-pit in the subsequent epitaxial layer subsequently formed on the stop layer. The first cross-sectional shape of the artificial micro-pit on the first reference plane parallel to the substrate 101 is a non-regular hexagon or a regular hexagon, that is, the shape of the artificial micro-pit is no longer limited to the hexagonal pyramid, and the shape and size of the artificial micro-pit are flexible and controllable, thereby optimizing the hole injection effect of the artificial micro-pit. The first cross-sectional shape of the artificial micro-pit in the embodiment of the present application on the first reference plane parallel to the substrate 101 is annular, specifically circular, elliptical or polygonal, and the first cross-sectional shape is asymmetric or symmetric relative to the central axis. In other embodiments, the first cross-sectional shape of the artificial micro-pit on the first reference plane parallel to the substrate 101 may also be other custom patterns.

[0032] Further, the second cross-sectional shape of the artificial micro-pit of the embodiment of the present application on the second reference plane perpendicular to the substrate 101 may include two side walls 12, 13 and a bottom wall 11, the two side walls 12, 13 are arranged opposite to each other and the bottom wall 11 connects the two side walls 12, 13, and the second cross-sectional shape may be non-conical. It should be noted that the bottom wall 11 is located in the stop layer, and the subsequent epitaxial layer further covers the two side walls 12, 13 and the bottom wall 11. The holes injected by the two side walls 12, 13 can not only be transmitted to the quantum well active layer 105 grown in the platform area outside the artificial micro-pit, but also can be transmitted to the quantum well active layer 105 grown at the bottom wall 11, thereby realizing the electron-hole recombination luminescence of the quantum well active layer 105 at the bottom wall 11, and the function of the lateral current injection of the two side walls 12, 13 is brought into play to a greater extent, reducing the loss of the luminous area and enhancing the light output.

[0033] It should be noted that since the adsorption capacity of the side walls 12 and 13 for reactants is weaker than that of the bottom wall 11, the width of the bottom wall 11 is set so that the total film thickness of the subsequent epitaxial layer on the bottom wall 11 is greater than the total film thickness of the subsequent epitaxial layer on the side walls 12 and 13.

[0034] Furthermore, the width of the bottom wall 11 is further set so that the ratio between the total film thickness of the subsequent epitaxial layer on the bottom wall 11 and the total film thickness of the subsequent epitaxial layer on the platform area outside the artificial micro-pit is 0.8 to 1. It can be understood that by controlling the ratio relationship between the two, a light-emitting device can be obtained in which the total film thickness of the subsequent epitaxial layer on the bottom wall 11 is consistent with or inconsistent with the total film thickness of the subsequent epitaxial layer on the platform area outside the artificial micro-pit.

[0035] In one embodiment, the artificial micropits are further divided into starting micropits and induced micropits. The starting micropits are artificially formed in the stop layer, and the induced micropits are formed in the subsequent epitaxial layer under the induction of the starting micropits as the subsequent epitaxial layer grows epitaxially. The starting micropit forms an opening on the surface of the stop layer facing the subsequent epitaxial layer, and the cross-sectional shape of the opening of the starting micropit on the first reference plane parallel to the substrate 101 is a non-regular hexagon or a regular hexagon, and the size of the opening of the starting micropit is set so that the cross-sectional shape of the induced micropit formed in the subsequent epitaxial layer during the epitaxial growth process on the first reference plane parallel to the substrate 101 is consistent with the cross-sectional shape of the opening on the first reference plane parallel to the substrate 101.

[0036] In one embodiment, the artificial micro-pits are formed by etching the subsequent epitaxial layer from a side of the subsequent epitaxial layer facing away from the substrate 101 .

[0037] Specifically, the subsequent epitaxial layer formed on the stop layer is etched from the side of the subsequent epitaxial layer away from the substrate 101 to form the starting micro-pit, and an induced micro-pit surrounding the starting micro-pit continues to be epitaxially grown under the induction of the starting micro-pit. Different from the V-shaped pit defined as an inverted hexagonal pyramid in the prior art, the shape and size of the artificial micro-pit in the embodiment of the present application are flexible and controllable. Specifically, the cross-sectional shape of the induced micro-pit on the first reference plane parallel to the substrate 101 and the cross-sectional shape of the opening on the first reference plane parallel to the substrate 101 can be a non-regular hexagon or a regular hexagon, and the cross-sectional shape of the induced micro-pit on the first reference plane parallel to the substrate 101 is consistent with the cross-sectional shape of the opening on the first reference plane parallel to the substrate 101.

[0038] like Figure 1As shown, the opening width w of the starting micropit is the maximum distance between any two points on the edge of the cross-sectional shape of the opening of the starting micropit. Wherein, the opening width w of the starting micropit is defined in the present application as 1nm to 10μm, and optionally, the opening width w of the starting micropit can be 1nm to 15nm, 15nm to 100nm, 100nm to 500nm, 500nm to 1000nm, 1μm to 5μm, 5μm to 10μm, for example, the opening width w of the starting micropit can be 1nm, 15nm, 20nm, 100nm, 500nm, 600nm, 750nm, 1000nm, 2μm, 5μm, 10μm.

[0039] like Figure 1 As shown, the pit depth d of the starting micropit is the vertical distance from a point on the starting micropit that is shortest from the main surface of the side of the substrate 101 away from the epitaxial layer to the main surface of the side of the stop layer away from the substrate 101. The pit depth d of the starting micropit is defined as 1nm to 10μm in the present application. Optionally, the pit depth d of the starting micropit can be 1nm to 15nm, 15nm to 100nm, 100nm to 500nm, 500nm to 1000nm, 1μm to 5μm, 5μm to 10μm. For example, the pit depth d of the starting micropit can be 1nm, 15nm, 20nm, 100nm, 500nm, 600nm, 750nm, 1000nm, 2μm, 5μm, 10μm.

[0040] Based on the growth principle of naturally formed V-shaped pits, the greater the pit depth of the naturally formed V-shaped pit, the greater the opening width is required, that is, the pit depth of the naturally formed V-shaped pit is positively correlated with the opening width of the naturally formed V-shaped pit. Therefore, the pit depth of the naturally formed V-shaped pit is limited by the size of the light-emitting device 100. Different from the prior art, the pit depth d of the starting micro-pit in the embodiment of the present application depends on the position of the stop layer and has no correlation with the opening width w of the starting micro-pit. Optionally, the ratio between the pit depth d of the starting micro-pit of the present application and the opening width w of the starting micro-pit is 1:10 to 100:1, for example, 1:10, 1:5, 1:1, 5:1, 10:1, 50:1, 100:1.

[0041] In one embodiment, the second cross-sectional shape of the artificial micro-pit on the second reference plane perpendicular to the substrate 101 has two side walls 12 and 13 opposite to each other, and the light-emitting device 100 has a platform area on the periphery of the artificial micro-pit, and the subsequent epitaxial layer is formed at least in the platform area, wherein the film composition of the side walls 12 and 13 on the side of the termination layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the platform area. Since the film composition of the side walls 12 and 13 on the side of the termination layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the platform area, the purpose of flexibly regulating the band structure of the side walls 12 and 13 is achieved, the hole injection path is optimized, and the hole injection barrier height is further reduced, the efficiency and uniformity of the lateral current injection of the side walls 12 and 13 are increased, and the luminous efficiency is improved.

[0042] like Figure 1 As shown, in one embodiment, the second cross-sectional shape of the artificial micro-pit on the second reference plane perpendicular to the substrate 101 has two side walls 12 and 13 opposite to each other, and the intersection angle α between at least one side wall 12 and 13 and the substrate 101 is different from the intersection angle between the natural growth crystal plane of the subsequent epitaxial layer and the substrate 101. The intersection angle α ranges from 15° to 90°.

[0043] Among them, the natural growth habit of the naturally grown crystal plane is different from the growth habit of the subsequent epitaxial layer artificially grown in the embodiment of the present application. Therefore, the intersection angle α between the side walls 12 and 13 related to the subsequent epitaxial layer and the substrate 101 is different from the intersection angle between the naturally grown crystal plane of the subsequent epitaxial layer and the substrate 101.

[0044] Through the above-mentioned method, the present application changes the natural growth habit of the crystal, so that the intersection angle between the side walls 12 and 13 of the second cross-sectional shape of the artificial micro-pit on the second reference plane perpendicular to the substrate 101 and the substrate 101 is flexibly controllable, thereby obtaining a second cross-sectional shape of different shapes. By increasing the angle value of the intersection angle α, an artificial micro-pit with a smaller duty cycle can be obtained, thereby reducing the loss of the epitaxial layer light-emitting area caused by the formation of artificial micro-pits and increasing the light output.

[0045] like Figure 6 As shown, the embodiment of the present application also provides a method for manufacturing the light emitting device 100 of the above embodiment, the method comprising:

[0046] S101: providing a substrate 101.

[0047] Specifically, the material of the substrate 101 includes, but is not limited to, at least one of sapphire, Si, SiC, GaN, ZnO, InP, and GaAs.

[0048] S102: using the substrate 101 and / or at least one epitaxial layer on the substrate 101 as a stop layer, and forming a starting micro-pit in the stop layer.

[0049] S103: Continue to grow a subsequent epitaxial layer on the stop layer, so that an induced micropit is formed in the subsequent epitaxial layer as the subsequent epitaxial layer grows epitaxially under the induction of the starting micropit, wherein the starting micropit forms an opening on the surface of the stop layer on one side facing the subsequent epitaxial layer, and the first cross-sectional shape of the opening on the first reference plane parallel to the substrate 101 is a non-regular hexagon or a regular hexagon, and the size of the opening is set so that the cross-sectional shape of the induced micropit on the first reference plane parallel to the substrate 101 is consistent with the cross-sectional shape of the opening on the first reference plane parallel to the substrate 101.

[0050] Specifically, when the substrate 101 is used as a stop layer, a starting micro-pit is prepared by an etching process on the substrate 101 that has not undergone epitaxial growth, and the subsequent first conductive type semiconductor layer 103, quantum well active layer 105 and second conductive type semiconductor layer 107 are continued to grow on the substrate 101 formed with the starting micro-pit. At this time, under the induction of the starting micro-pit, an induced micro-pit is formed in the above-mentioned epitaxial layer along with the epitaxial growth of the above-mentioned epitaxial layer, and the opening of the starting micro-pit and the cross-sectional shape of the induced micro-pit on the first reference plane parallel to the substrate 101 are both non-regular hexagons or both are regular hexagons.

[0051] Alternatively, when the first conductive type semiconductor layer 103 is used as the stop layer, after the first conductive type semiconductor layer 103 is epitaxially grown on the substrate 101, the epitaxy is interrupted, a starting micro-pit is prepared on the first conductive type semiconductor layer 103 by an etching process, and the subsequent quantum well active layer 105 and the second conductive type semiconductor layer 107 are continuously grown on the first conductive type semiconductor layer 103 with the starting micro-pit formed. At this time, under the induction of the starting micro-pit, induced micro-pits are formed in the quantum well active layer 105 and the second conductive type semiconductor layer 107 along with the epitaxial growth of the above-mentioned epitaxial layer, and the opening of the starting micro-pit and the cross-sectional shape of the induced micro-pit on the first reference plane parallel to the substrate 101 are both non-regular hexagons or both are regular hexagons.

[0052] Alternatively, when the quantum well active layer 105 is used as the stop layer, after the first conductive type semiconductor layer 103 and the quantum well active layer 105 are epitaxially grown in sequence on the substrate 101, the epitaxy is interrupted, and a starting micro-pit is prepared on the quantum well active layer 105 by an etching process, and the subsequent second conductive type semiconductor layer 107 is continued to grow on the quantum well active layer 105 with the starting micro-pit. At this time, under the induction of the starting micro-pit, an induced micro-pit is formed in the second conductive type semiconductor layer 107 along with the epitaxial growth of the above-mentioned epitaxial layer, and the opening of the starting micro-pit and the cross-sectional shape of the induced micro-pit on the first reference plane parallel to the substrate 101 are both non-regular hexagons or both are regular hexagons.

[0053] Alternatively, when the substrate 101 and the first conductive type semiconductor layer 103 are used as stop layers, after the first conductive type semiconductor layer 103 is epitaxially grown on the substrate 101, the epitaxy is interrupted, and starting micro-pits are prepared on the substrate 101 and the first conductive type semiconductor layer 103 by an etching process, and the subsequent quantum well active layer 105 and the second conductive type semiconductor layer 107 are continued to grow on the side of the first conductive type semiconductor layer 103 with the starting micro-pits away from the substrate 101. At this time, under the induction of the starting micro-pits, induced micro-pits are formed in the quantum well active layer 105 and the second conductive type semiconductor layer 107 along with the epitaxial growth of the above-mentioned epitaxial layers, and the opening of the starting micro-pit and the cross-sectional shape of the induced micro-pit on the first reference plane parallel to the substrate 101 are both non-regular hexagons or both are regular hexagons.

[0054] Different from the prior art, the artificial micro-pits produced by the manufacturing method provided by the present application use the substrate 101 and / or at least one of the multiple epitaxial layers as a stop layer, and extend to the subsequent epitaxial layer subsequently formed on the stop layer, that is, the present application can break through the limiting factors of the existing "artificial V-shaped pits" and select any substrate 101 and / or epitaxial layer as the stop layer of the artificial micro-pits. Therefore, the spatial position of the artificial micro-pits of the present application is no longer simply determined by dislocations, but the artificial micro-pits extending to the subsequent epitaxial layer subsequently formed on the stop layer have a first cross-sectional shape on a first reference plane parallel to the substrate 101 that is a non-regular hexagon or a regular hexagon, that is, the shape of the artificial micro-pits is no longer limited to a hexagonal pyramid, and the shape and size of the artificial micro-pits are flexibly controllable, thereby optimizing the hole injection effect of the artificial micro-pits.

[0055] like Figure 7 As shown, the embodiment of the present application also provides a method for manufacturing the light emitting device 100 of the above embodiment, the method comprising:

[0056] S201: providing a substrate 101.

[0057] Specifically, the material of the substrate 101 includes, but is not limited to, at least one of sapphire, Si, SiC, GaN, ZnO, InP, and GaAs.

[0058] S202: Form a plurality of epitaxial layers on the substrate 101 by epitaxial growth.

[0059] A first conductive type semiconductor layer 103 and a quantum well active layer 105 are formed on the substrate 101 by epitaxial growth, or a first conductive type semiconductor layer 103 , a quantum well active layer 105 and a second conductive type semiconductor layer 107 are formed on the substrate 101 by epitaxial growth.

[0060] More specifically, a buffer layer 102, a first conductive type semiconductor layer 103, a pre-well preparation layer 104, a quantum well active layer 105 and / or a superlattice quantum well active layer 105, an electron blocking layer 106, a second conductive type semiconductor layer 107 and / or a second conductive type heavily doped semiconductor layer are formed by epitaxial growth on the substrate 101. The stop layer may be at least two continuous stacks of the buffer layer 102, the first conductive type semiconductor layer 103, the pre-well preparation layer 104, the quantum well active layer 105, the superlattice quantum well active layer 105, the electron blocking layer 106, the second conductive type semiconductor layer 107, and the second conductive type heavily doped semiconductor layer.

[0061] S203: using the substrate 101 and / or at least one of the multiple epitaxial layers as a stop layer.

[0062] S204: etching the subsequent epitaxial layer subsequently formed on the stop layer from the side facing away from the substrate 101 to form a plurality of artificial micro-pits, wherein the first cross-sectional shape of the artificial micro-pits on a first reference plane parallel to the substrate 101 is a non-regular hexagon or a regular hexagon.

[0063] Specifically, when the substrate 101 is used as a stop layer, the second conductive type semiconductor layer 107, the quantum well active layer 105 and the first conductive type semiconductor layer 103 are etched from the side of the second conductive type semiconductor layer 107 away from the substrate 101 to form a plurality of artificial micro-pits, wherein the first cross-sectional shape of the artificial micro-pits on a first reference plane parallel to the substrate 101 is a non-regular hexagon or a regular hexagon.

[0064] Alternatively, when the first conductive type semiconductor layer 103 is used as a stop layer, the second conductive type semiconductor layer 107 and the quantum well active layer 105 are etched from the side of the second conductive type semiconductor layer 107 facing away from the substrate 101 to form a plurality of artificial micro-pits, wherein the first cross-sectional shape of the artificial micro-pits on a first reference plane parallel to the substrate 101 is a non-regular hexagon or a regular hexagon.

[0065] Alternatively, when the quantum well active layer 105 is used as a stop layer, the second conductive type semiconductor layer 107 is etched from the side of the second conductive type semiconductor layer 107 facing away from the substrate 101 to form a plurality of artificial micro-pits, wherein the first cross-sectional shape of the artificial micro-pits on a first reference plane parallel to the substrate 101 is a non-regular hexagon or a regular hexagon.

[0066] Furthermore, a mask layer can be deposited on the stop layer and patterned to obtain a mask pattern. The mask layer can be an organic photoresist, or a non-metallic compound such as SiO2, Si3N4, or a metal layer. The deposition method includes but is not limited to chemical vapor deposition, physical vapor deposition, and electrochemical deposition. The patterning method includes but is not limited to dry etching, wet etching, and stripping. The non-mask area is etched using the mask pattern to form a plurality of artificial micro-pits. The etching rate, angle, anisotropy, etc. can be adjusted by changing the process parameters, and the depth, cross-sectional shape, and angles of the sidewalls 12 and 13 of the artificial micro-pits can be controlled.

[0067] Different from the prior art, the artificial micro-pits produced by the manufacturing method provided by the present application use the substrate 101 and / or at least one of the multiple epitaxial layers as a stop layer, and extend to the subsequent epitaxial layer subsequently formed on the stop layer, that is, the present application can break through the limiting factors of the existing "artificial V-shaped pits" and select any substrate 101 and / or epitaxial layer as the stop layer of the artificial micro-pits. Therefore, the spatial position of the artificial micro-pits of the present application is no longer simply determined by dislocations, but the artificial micro-pits extending to the subsequent epitaxial layer subsequently formed on the stop layer have a first cross-sectional shape on a first reference plane parallel to the substrate 101 that is a non-regular hexagon or a regular hexagon, that is, the shape of the artificial micro-pits is no longer limited to a hexagonal pyramid, and the shape and size of the artificial micro-pits are flexibly controllable, thereby optimizing the hole injection effect of the artificial micro-pits.

[0068] The specific embodiments of the present application are described in detail below in combination with the technical solutions and drawings.

[0069] Example 1

[0070] like Figure 1 As shown, the light emitting device 100 includes a substrate 101, and a buffer layer 102 and an N-type GaN layer 103 sequentially stacked on the substrate 101 by epitaxial growth. With the N-type GaN layer 103 as a stop layer, an initial micro-pit is formed on the N-type GaN layer 103 by an etching process, and the subsequent pre-well preparation layer 104, the MQW layer 105, the electron blocking layer 106 and the P-type GaN layer 107 are sequentially grown on the N-type GaN layer 103 formed with the initial micro-pit. Under the induction of the initial micro-pit, an induced micro-pit is formed in the subsequent epitaxial layer with the epitaxial growth of the subsequent epitaxial layer. The cross-sectional shapes of the openings of the induced micro-pit and the initial micro-pit on the first reference plane parallel to the substrate 101 are consistent and may be non-regular hexagonal. The initial micropits and the induced micropits constitute artificial micropits of the light-emitting device 100 , wherein the bottom wall 11 of the artificial micropit is located in the N-type GaN layer 103 , and the bottom wall 11 of the artificial micropit is parallel to the main surface of the substrate 101 close to the buffer layer 102 .

[0071] Example 2

[0072] like Figure 2 As shown, the light emitting device 100 includes a substrate 101 and a buffer layer 102 and an N-type GaN layer 103 sequentially stacked on the substrate 101 by epitaxial growth. With the N-type GaN layer 103 as a stop layer, an initial micro-pit is formed on the N-type GaN layer 103 by an etching process, and the subsequent pre-well preparation layer 104, the MQW layer 105, the electron blocking layer 106 and the P-type GaN layer 107 are sequentially grown on the N-type GaN layer 103 formed with the initial micro-pit. Under the induction of the initial micro-pit, an induced micro-pit is formed in the subsequent epitaxial layer with the epitaxial growth of the subsequent epitaxial layer. The cross-sectional shapes of the induced micro-pit and the opening of the initial micro-pit on the first reference plane parallel to the substrate 101 are consistent and may be non-regular hexagonal. The initial micro-pit and the induced micro-pit constitute an artificial micro-pit of the light emitting device 100, wherein the bottom wall 11 of the artificial micro-pit is located in the N-type GaN layer 103, and the bottom wall 11 of the artificial micro-pit includes a first plane and a second plane that are angled with each other.

[0073] Example 3

[0074] like Figure 3 As shown, the light emitting device 100 includes a substrate 101 and a buffer layer 102 and an N-type GaN layer 103 sequentially stacked on the substrate 101 by epitaxial growth. With the N-type GaN layer 103 as a stop layer, an initial micro-pit is formed on the N-type GaN layer 103 by an etching process, and the subsequent pre-well preparation layer 104, the MQW layer 105, the electron blocking layer 106 and the P-type GaN layer 107 are sequentially grown on the N-type GaN layer 103 formed with the initial micro-pit. Under the induction of the initial micro-pit, an induced micro-pit is formed in the subsequent epitaxial layer with the epitaxial growth of the subsequent epitaxial layer. The cross-sectional shapes of the induced micro-pit and the opening of the initial micro-pit on the first reference plane parallel to the substrate 101 are consistent and may be non-regular hexagonal. The initial micro-pit and the induced micro-pit constitute an artificial micro-pit of the light emitting device 100, wherein the bottom wall 11 of the artificial micro-pit is located in the N-type GaN layer 103, and the bottom wall 11 of the artificial micro-pit is a curved surface.

[0075] Example 4

[0076] like Figure 4As shown, the light emitting device 100 includes a substrate 101 and a buffer layer 102, an N-type GaN layer 103 and a pre-well preparation layer 104 which are sequentially stacked on the substrate 101 by epitaxial growth. The pre-well preparation layer 104 is used as a stop layer, and an initial micro-pit is formed on the pre-well preparation layer 104 by an etching process, wherein a custom epitaxial layer 108 is formed on the side of the initial micro-pit away from the substrate 101, and the material of the custom epitaxial layer 108 is a material with carrier transmission capability. Further, the subsequent MQW layer 105, the electron blocking layer 106 and the P-type GaN layer 107 are sequentially grown on the side of the pre-well preparation layer 104 and the custom epitaxial layer 108 formed with the initial micro-pit away from the substrate 101, and the induced micro-pit is formed in the subsequent epitaxial layer with the epitaxial growth of the subsequent epitaxial layer under the induction of the initial micro-pit, and the cross-sectional shape of the opening of the induced micro-pit and the initial micro-pit on the first reference plane parallel to the substrate 101 is consistent and can be a non-regular hexagon. The starting micropits and the induced micropits constitute artificial micropits of the light emitting device 100 , wherein the bottom wall 11 of the artificial micropit is located in the pre-well preparation layer 104 , and the bottom wall 11 of the artificial micropit is parallel to the main surface of the substrate 101 close to the buffer layer 102 .

[0077] Example 5

[0078] like Figure 5 As shown, the light emitting device 100 includes a substrate 101 and a buffer layer 102, an N-type GaN layer 103, a pre-well preparation layer 104, and a multi-quantum well active (MQW) layer 105 composed of a plurality of potential wells, which are sequentially stacked on the substrate 101 by epitaxial growth. The MQW layer 105 is used as a stop layer, and an initial micro-pit is formed on the MQW layer 105 by an etching process, wherein a custom epitaxial layer 108 is formed on the side of the initial micro-pit away from the substrate 101, and the material of the custom epitaxial layer 108 is a material with electron transmission capability. Further, on the side of the MQW layer 105 and the custom epitaxial layer 108 away from the substrate 101 where the starting micropit is formed, the subsequent remaining MQW layer 105, the electron blocking layer 106 and the P-type GaN layer 107 are sequentially grown, and the induced micropits in the subsequent epitaxial layer are formed with the epitaxial growth of the subsequent epitaxial layer under the induction of the starting micropit, and the cross-sectional shapes of the openings of the induced micropits and the starting micropits on the first reference plane parallel to the substrate 101 are consistent and may be non-regular hexagonal. The starting micropits and the induced micropits constitute the artificial micropits of the light-emitting device 100, wherein the bottom wall 11 of the artificial micropit is located in the MQW layer 105, and the bottom wall 11 of the artificial micropit is parallel to the main surface of the substrate 101 close to the buffer layer 102.

[0079] The artificial micro-pits of the present application use a substrate and / or at least one epitaxial layer in the multiple epitaxial layers as a stop layer, and extend to a subsequent epitaxial layer subsequently formed on the stop layer, that is, the present application can break through the limiting factors of the existing "artificial V-shaped pits" and select any substrate and / or epitaxial layer as the stop layer of the artificial micro-pits. Therefore, the spatial position of the artificial micro-pits of the present application is no longer simply determined by dislocations, but the artificial micro-pits extending to the subsequent epitaxial layers subsequently formed on the stop layer have a first cross-sectional shape on a first reference plane parallel to the substrate that is a non-regular hexagon or a regular hexagon, that is, the shape of the artificial micro-pits is no longer limited to a hexagonal pyramid, and the shape and size of the artificial micro-pits are flexibly controllable, thereby optimizing the hole injection effect of the artificial micro-pits.

[0080] The above are only implementation methods of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A light emitting device, characterized in that: The light emitting device comprises a substrate and a plurality of epitaxial layers formed on the substrate by epitaxial growth, wherein a plurality of artificial micro-pits are arranged in the light emitting device, wherein the artificial micro-pits use the substrate and / or at least one epitaxial layer of the plurality of epitaxial layers as a stop layer and extend to a subsequent epitaxial layer subsequently formed on the stop layer, wherein a first cross-sectional shape of the artificial micro-pits on a first reference plane parallel to the substrate is a non-regular hexagon or a regular hexagon; The artificial micro-pits are further divided into starting micro-pits artificially formed in the stop layer and induced micro-pits formed in the subsequent epitaxial layer as the subsequent epitaxial layer grows epitaxially under the induction of the starting micro-pits, wherein the starting micro-pits form an opening on the surface of the stop layer on one side facing the subsequent epitaxial layer, and the cross-sectional shape of the opening on a first reference plane parallel to the substrate is a non-regular hexagon or a regular hexagon, and the size of the opening is set so that the cross-sectional shape of the induced micro-pits formed in the epitaxial growth process of the subsequent epitaxial layer on the first reference plane parallel to the substrate is consistent with the cross-sectional shape of the opening on the first reference plane parallel to the substrate.

2. The light emitting device according to claim 1, characterized in that: The ratio of the width of the opening to the pit depth of the initial micro-pit is 1:10 to 100:

1.

3. The light emitting device according to claim 1, characterized in that: The width of the opening is 1 nm to 10 μm.

4. The light emitting device according to claim 1, characterized in that: The pit depth of the initial micropit is 1 nm to 10 μm.

5. The light emitting device according to claim 1, characterized in that: The density of the artificial micro-pits is 1×10 7 ~5×10 9 / cm 2 .

6. The light emitting device according to claim 1, characterized in that: The second cross-sectional shape of the artificial micro-pit on a second reference plane perpendicular to the substrate has two side walls and a bottom wall, wherein the two side walls are arranged opposite to each other, the bottom wall is located in the stop layer and connects the two side walls, and the subsequent epitaxial layer further covers the side walls and the bottom wall.

7. The light emitting device according to claim 6, characterized in that: The width of the bottom wall is set so that the total film thickness of the subsequent epitaxial layer on the bottom wall is greater than the total film thickness of the subsequent epitaxial layer on the side wall.

8. The light emitting device according to claim 7, characterized in that: The width of the bottom wall is further set so that the ratio between the total film thickness of the subsequent epitaxial layer on the bottom wall and the total film thickness of the subsequent epitaxial layer on the platform area outside the artificial micro-pit is 0.8-1.

9. The light emitting device according to claim 1, characterized in that: The artificial micro-pit has two side walls opposite to each other in a second cross-sectional shape on a second reference plane perpendicular to the substrate, and the light-emitting device has a platform area on the periphery of the artificial micro-pit, and the subsequent epitaxial layer is formed at least in the platform area, wherein the film layer composition of the side wall on the side of the stop layer toward the subsequent epitaxial layer is different from the film layer composition of the subsequent epitaxial layer in the platform area.

10. The light emitting device according to claim 1, characterized in that: The second cross-sectional shape of the artificial micropit on a second reference plane perpendicular to the substrate has two side walls opposite to each other, and the intersection angle between at least one of the side walls and the substrate is different from the intersection angle between the natural growth crystal plane of the subsequent epitaxial layer and the substrate.

11. A method for manufacturing a light emitting device, characterized in that: The method comprises: providing a substrate; Using the substrate and / or at least one epitaxial layer on the substrate as a stop layer, and forming a starting micro-pit in the stop layer; The subsequent epitaxial layer continues to grow on the stop layer, so that an induced micropit is formed in the subsequent epitaxial layer as the subsequent epitaxial layer grows epitaxially under the induction effect of the starting micropit, wherein the starting micropit forms an opening on the surface of the stop layer on one side facing the subsequent epitaxial layer, and the first cross-sectional shape of the opening on a first reference plane parallel to the substrate is a non-regular hexagon or a regular hexagon, and the size of the opening is set so that the cross-sectional shape of the induced micropit on the first reference plane parallel to the substrate is consistent with the cross-sectional shape of the opening on the first reference plane parallel to the substrate.

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