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 in an epitaxial generation manner, 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 artificial micro-pits have two side walls opposite to each other in a first cross-sectional shape on a first reference plane perpendicular to the substrate, and the light-emitting device has a platform region at the periphery of the artificial micro-pits, wherein the subsequent epitaxial layer is at least located in the platform region, and the film composition of the side wall on the side of the stop layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the platform region. By the above method, the sidewall band structure of the artificial micro-pits is made flexible and controllable, and the hole injection effect of the artificial micro-pits is optimized.

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] During the long-term research and development process, the inventors of the present application discovered that the principle of the naturally formed V-shaped pits is that the temperature of the superlattice growth layer is low and the lateral epitaxial ability of the nitride (such as GaN) is poor. At this time, penetrating dislocations will form V-shaped pits. The existing "artificial V-shaped pits" are formed by artificially intervening in the dislocation distribution based on the above principle. Therefore, they can only optimize the side wall thickness and In content of the V-shaped pits, and do not change the band structure of the side wall of the V-shaped pit.

[0004] Therefore, it is necessary to design an artificial micropit with flexible and controllable sidewall band structure. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a light-emitting device and a method for manufacturing the same, so that the sidewall band structure of the artificial micro-pit in the first cross-sectional shape on the first reference plane perpendicular to the substrate is flexibly controllable, thereby optimizing the hole injection effect of the artificial micro-pit.

[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 in an epitaxial generation manner, 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 in the plurality of 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 two side walls opposite to each other in a first cross-sectional shape on a first reference plane perpendicular to the substrate, and the light-emitting device has a platform region at the periphery of the artificial micro-pits, and the subsequent epitaxial layer is at least located in the platform region, wherein the film layer composition of the side wall on the side of the stop layer facing the subsequent epitaxial layer is different from the film layer composition of the subsequent epitaxial layer in the platform region.

[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; performing differentiated epitaxial growth on the stop layer in the area where the starting micro-pit is located and the peripheral area of ​​the starting micro-pit, so that under the induction of the starting micro-pit, an induced micro-pit is formed in a subsequent epitaxial layer subsequently grown on the stop layer, wherein the starting micro-pit and the induced micro-pit cooperate to form an artificial micro-pit, wherein the artificial micro-pit has two side walls opposite to each other in a first cross-sectional shape on a first reference plane perpendicular to the substrate, and a platform area is formed on the periphery of the artificial micro-pit, and the film layer composition of the side wall on the side of the stop layer facing the subsequent epitaxial layer is different from the film layer composition of the subsequent epitaxial layer in the platform area.

[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 the 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, and forming a platform area around the artificial micro-pits, wherein the artificial micro-pits have two side walls opposite to each other in a first cross-sectional shape on a first reference plane perpendicular to the substrate; performing subsequent epitaxial growth on at least the area where the artificial micro-pits are located so that the film composition of the side wall on the side of the stop layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the platform area.

[0009] Different from the prior art, the artificial micro-pits of the present application use a substrate 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", select any substrate and / or epitaxial layer as the stop layer of the artificial micro-pits, and the film composition of the side wall on the side of the stop layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the platform area, thereby achieving the purpose of regulating the side wall band structure, optimizing the hole injection path, and further reducing the hole injection barrier height, increasing the efficiency and uniformity of side wall lateral current injection, and improving the luminescence efficiency. 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 1It is a structural schematic diagram corresponding to the manufacturing process of the light-emitting device provided in the first embodiment of the present application;

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

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

[0014] Figure 4 is a structural schematic diagram corresponding to the manufacturing process of the light-emitting device provided in the 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 structural diagram of a light-emitting device provided in a sixth embodiment of the present application;

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

[0018] Figure 8 It is a schematic flow chart of a method for manufacturing a light-emitting device provided in the eighth embodiment of the present application. DETAILED DESCRIPTION

[0019] 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.

[0020] like Figures 1 to 6 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.

[0021] A plurality of artificial micro-pits are arranged in the light emitting device 100 . The artificial micro-pits use the substrate 101 and / or at least one epitaxial layer in the multiple epitaxial layers as a stop layer and extend into a subsequent epitaxial layer subsequently formed on the stop layer.

[0022] The artificial micro-pit of the embodiment of the present application has two side walls opposite to each other in the first cross-sectional shape on the first reference plane perpendicular to the substrate 101, 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 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, wherein the first cross-sectional shape can be a non-isosceles triangle.

[0023] The second cross-sectional shape of the artificial micro-pit in the embodiment of the present application on the second reference plane parallel to the substrate 101 is a closed ring, which can be a circle, an ellipse or a polygon, and the second cross-sectional shape is asymmetric or symmetric relative to the central axis. In other embodiments, the second cross-sectional shape of the artificial micro-pit on the second reference plane parallel to the substrate 101 can also be other custom patterns.

[0024] 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.

[0025] 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 or a second conductive type heavily doped semiconductor layer) stacked in sequence on a substrate 101.

[0026] Furthermore, the material system of the MQW 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.

[0027] 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 , an MQW layer 105 , an electron blocking layer 106 , and a second conductive type semiconductor layer 107 sequentially stacked on the substrate 101 .

[0028] The artificial micro-pits may use at least one of the first conductive type semiconductor layer 103 , the MQW 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.

[0029] For example, the artificial micro-pits use the first conductive type semiconductor layer 103 as a stop layer and extend into the MQW layer 105 and the second conductive type semiconductor layer 107 that are subsequently formed on the first conductive type semiconductor layer 103 .

[0030] For another example, the artificial micro-pits use the first conductive type semiconductor layer 103 as a stop layer and extend to the MQW layer 105 subsequently formed on the first conductive type semiconductor layer 103. At this time, the MQW layer 105 is used as a stop layer again and extends to the second conductive type semiconductor layer 107 subsequently formed on the MQW layer 105.

[0031] 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 MQW layer 105 , and the second conductive type semiconductor layer 107 that are subsequently formed on the substrate 101 .

[0032] 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 subsequently formed on the substrate 101, and then use the first conductive type semiconductor layer 103 as a stop layer and extend into the MQW layer 105 and the second conductive type semiconductor layer 107 subsequently formed on the first conductive type semiconductor layer 103.

[0033] 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 MQW layer 105 subsequently formed on the first conductive type semiconductor layer 103, and then use the MQW layer 105 as a stop layer and extend into a second conductive type semiconductor layer 107 subsequently formed on the MQW layer 105.

[0034] Among them, the first cross-sectional shape of the artificial micro-pit on the first reference plane perpendicular to the substrate 101 has two side walls opposite to each other, and the light-emitting device 100 has a platform area outside the artificial micro-pit, and the subsequent epitaxial layer is at least located in the platform area. Therefore, in the embodiment of the present application, the holes injected from the side wall can be transmitted to the subsequent epitaxial layer located in the platform area outside the artificial micro-pit.

[0035] In addition, the film composition of the sidewall on the side of the stop layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the platform region. It should be noted that the "film composition of the sidewall on the side of the stop layer facing the subsequent epitaxial layer" in the embodiment of the present application may include materials for realizing lateral hole transport.

[0036] Different from the prior art, the artificial micro-pit of the present application uses the substrate 101 and / or at least one of 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 pits", select any substrate 101 and / or epitaxial layer as the stop layer of the artificial micro-pit, and the film composition of the side wall on the side of the stop layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the platform area, thereby achieving the purpose of regulating the side wall band structure, optimizing the hole injection path, and further reducing the hole injection barrier height, increasing the efficiency and uniformity of side wall lateral current injection, and improving the luminescence efficiency.

[0037] In one embodiment, the number of film layers of the sidewall on the side of the stop layer facing the subsequent epitaxial layer is less than or greater than the number of film layers of the subsequent epitaxial layer in the terrace region.

[0038] In one embodiment, the film composition of the sidewall on the side of the stop layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the terrace region.

[0039] In one embodiment, the film layer of the sidewall on the side of the stop layer facing the subsequent epitaxial layer includes at least one custom epitaxial layer 108 different from the subsequent epitaxial layer in the terrace region.

[0040] It can be understood that the embodiments of the present application can make the light-emitting device emit two or more colors of light or white light by regulating the film layer composition of the side wall on the side of the stop layer facing the subsequent epitaxial layer and / or the film layer composition of the subsequent epitaxial layer in the platform area. For example, the film layer of the side wall on the side of the stop layer facing the subsequent epitaxial layer and the film layer of the subsequent epitaxial layer in the platform area can use different color light-emitting materials.

[0041] In one embodiment, the custom epitaxial layer 108 is a carrier injection layer.

[0042] The material of the carrier injection layer may include but is not limited to: indium gallium nitride, aluminum gallium nitride, aluminum indium gallium, zinc oxynitride, and the conductivity type of the carrier injection layer is: N-type, P-type or intrinsic.

[0043] In one embodiment, the artificial micropits are further divided into starting micropits artificially formed in the stop layer and induced micropits formed in the subsequent epitaxial layer as the subsequent epitaxial layer is epitaxially generated under the induction of the starting micropits, wherein the starting micropit forms an opening on the surface of the stop layer on one side facing the subsequent epitaxial layer, and the size of the opening is set so that the cross-sectional shape of the induced micropit formed in the epitaxial generation process of the subsequent epitaxial layer on the second reference plane parallel to the substrate 101 is consistent with the cross-sectional shape of the opening on the second reference plane parallel to the substrate 101.

[0044] 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 .

[0045] Specifically, the subsequent epitaxial layer subsequently formed on the stop layer is etched from the side facing away from the substrate 101 to form the starting micro-pit, and an induced micro-pit surrounding the starting micro-pit is continuously epitaxially grown under the induction of the starting micro-pit.

[0046] like Figure 1 As 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.

[0047] 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.

[0048] 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.

[0049] like Figure 4 As shown, in one embodiment, the intersection angle between at least one side wall 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 ranges from 15° to 90°.

[0050] 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.

[0051] 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 first cross-sectional shape of the artificial micro-pit on the first reference plane perpendicular to the substrate 101 and the substrate 101 is flexibly controllable, thereby obtaining first cross-sectional shapes of different shapes. Furthermore, 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.

[0052] It should be noted that the first cross-sectional shape of the artificial micro-pit in the embodiment of the present application on the first reference plane perpendicular to the substrate 101 may also have a bottom wall, which is located in the stop layer and connects the two side walls, wherein the bottom wall may be in a step shape.

[0053] 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:

[0054] S101: providing a substrate 101.

[0055] 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.

[0056] 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.

[0057] S103: Performing differentiated epitaxial growth on the stop layer in the area where the starting micro-pit is located and in the peripheral area of ​​the starting micro-pit, so that an induced micro-pit is formed in the subsequent epitaxial layer subsequently grown on the stop layer under the induction effect of the starting micro-pit, wherein the starting micro-pit and the induced micro-pit cooperate to form an artificial micro-pit, wherein the artificial micro-pit has two side walls opposite to each other in a first cross-sectional shape on a first reference plane perpendicular to the substrate 101, and a platform area is formed at the periphery of the artificial micro-pit, and the film layer composition of the side wall on the side of the stop layer facing the subsequent epitaxial layer is different from the film layer composition of the subsequent epitaxial layer in the platform area.

[0058] 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 differentiated epitaxial growth is performed on the substrate 101 in the area where the starting micro-pit is located and the peripheral area of ​​the starting micro-pit, so that under the induction of the starting micro-pit, an induced micro-pit is formed in a subsequent epitaxial layer (for example, the first conductive type semiconductor layer 103, the MQW layer 105 and the second conductive type semiconductor layer 107) subsequently grown on the substrate 101, wherein the starting micro-pit and the induced micro-pit cooperate to form an artificial micro-pit, and a platform area is formed at the periphery of the artificial micro-pit, and the film layer composition of the side wall of the artificial micro-pit in the first cross-sectional shape on the first reference plane perpendicular to the substrate 101 on the side of the substrate 101 facing the subsequent epitaxial layer is different from the film layer composition of the subsequent epitaxial layer in the platform area.

[0059] Alternatively, when the MQW layer 105 is used as the stop layer, after the first conductive type semiconductor layer 103 and the MQW layer 105 are epitaxially grown on the substrate 101, the epitaxy is interrupted, a starting micro-pit is prepared on the MQW layer 105 by an etching process, and differentiated epitaxial growth is performed on the substrate 101 in the area where the starting micro-pit is located and the peripheral area of ​​the starting micro-pit, so that under the induction of the starting micro-pit, an induced micro-pit is formed in a subsequent epitaxial layer (for example, the second conductive type semiconductor layer 107) subsequently grown on the MQW layer 105, wherein the starting micro-pit and the induced micro-pit cooperate to form an artificial micro-pit, and a platform area is formed on the periphery of the artificial micro-pit, and the film layer composition of the side wall of the artificial micro-pit in the first cross-sectional shape on the first reference plane perpendicular to the substrate 101 on the side of the substrate 101 facing the subsequent epitaxial layer is different from the film layer composition of the subsequent epitaxial layer in the platform area.

[0060] Alternatively, when the electron blocking layer 106 is used as the stop layer, after the buffer layer 102, the first conductive type semiconductor layer 103, the pre-well preparation layer 104, the MQW layer 105 and the electron blocking layer 106 are epitaxially grown in sequence on the substrate 101, the epitaxy is interrupted, a starting micro-pit is prepared on the electron blocking layer 106 by an etching process, and differentiated epitaxial growth is performed on the electron blocking layer 106 in the area where the starting micro-pit is located and the peripheral area of ​​the starting micro-pit, so that under the induction of the starting micro-pit, an induced micro-pit is formed in a subsequent epitaxial layer (for example, the second conductive type semiconductor layer 107 or the second conductive type heavily doped semiconductor layer) subsequently grown on the electron blocking layer 106, wherein the starting micro-pit and the induced micro-pit cooperate to form an artificial micro-pit, and a platform area is formed at the periphery of the artificial micro-pit, and the film layer composition of the sidewall of the artificial micro-pit in the first cross-sectional shape on the first reference plane perpendicular to the substrate 101 on the side of the substrate 101 facing the subsequent epitaxial layer is different from the film layer composition of the subsequent epitaxial layer in the platform area.

[0061] 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, epitaxy is interrupted, a starting micropit is prepared on the substrate 101 and the first conductive type semiconductor layer 103 by an etching process, and differential epitaxial growth is performed on the area where the starting micropit is located and the peripheral area of ​​the starting micropit on the side of the first conductive type semiconductor layer 103 away from the substrate 101, so that an induced micropit is formed in a subsequent epitaxial layer (such as the MQW layer 105 and the second conductive type semiconductor layer 107) subsequently grown on the first conductive type semiconductor layer 103 under the induction of the starting micropit, wherein the starting micropit and the induced micropit cooperate to form an artificial micropit, and a platform area is formed at the periphery of the artificial micropit, and the film layer composition of the sidewall of the artificial micropit in the first cross-sectional shape on the first reference plane perpendicular to the substrate 101 on the side of the first conductive type semiconductor layer 103 facing the subsequent epitaxial layer is different from the film layer composition of the subsequent epitaxial layer in the platform area. .

[0062] Different from the prior art, the artificial micro-pits obtained 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", select any substrate 101 and / or epitaxial layer as the stop layer of the artificial micro-pit, and the film composition of the side wall on the side of the stop layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the platform area, thereby achieving the purpose of regulating the side wall band structure, optimizing the hole injection path, and further reducing the hole injection barrier height, increasing the efficiency and uniformity of the side wall lateral current injection, and improving the luminescence efficiency.

[0063] like Figure 8 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:

[0064] S201: providing a substrate 101.

[0065] 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.

[0066] S202: Form a plurality of epitaxial layers on the substrate 101 by epitaxial growth.

[0067] A first conductive type semiconductor layer 103 and an MQW layer 105 are stacked on the substrate 101 by epitaxial growth, or a first conductive type semiconductor layer 103 , an MQW layer 105 and a second conductive type semiconductor layer 107 are stacked on the substrate 101 by epitaxial growth.

[0068] More specifically, a buffer layer 102, a first conductivity type semiconductor layer 103, a pre-well preparation layer 104, an MQW layer 105 and / or a superlattice MQW layer 105, an electron blocking layer 106, a second conductivity type semiconductor layer 107 and / or a second conductivity 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 conductivity type semiconductor layer 103, the pre-well preparation layer 104, the MQW layer 105, the superlattice MQW layer 105, the electron blocking layer 106, the second conductivity type semiconductor layer 107, and the second conductivity type heavily doped semiconductor layer.

[0069] S203: using the substrate 101 and / or at least one of the plurality of epitaxial layers as a stop layer.

[0070] S204: Etching the subsequent epitaxial layer subsequently formed on the stop layer from a side away from the substrate 101 to form a plurality of artificial micro-pits, and forming a platform area around the artificial micro-pits, wherein the artificial micro-pits have two side walls opposite to each other in a first cross-sectional shape on a first reference plane perpendicular to the substrate 101.

[0071] S205: performing subsequent epitaxial growth on at least the region where the artificial micro-pit is located, so that the film composition of the sidewall on the side of the stop layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the platform region.

[0072] Specifically, when the substrate 101 is used as a stop layer, the second conductive type semiconductor layer 107, the MQW 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, and a platform region is formed around the artificial micro-pits. Further, subsequent epitaxial growth is performed on at least the region where the artificial micro-pits are located, so that the film layer composition of the sidewall of the artificial micro-pit in the first cross-sectional shape on the first reference plane perpendicular to the substrate 101 on the side of the substrate 101 facing the subsequent epitaxial layer is different from the film layer composition of the subsequent epitaxial layer in the platform region.

[0073] Alternatively, when the MQW layer 105 is used as a stop layer, the second conductive type semiconductor layer 107 is etched from a side of the second conductive type semiconductor layer 107 away from the MQW layer 105 to form a plurality of artificial micro-pits, and a platform region is formed around the artificial micro-pits. Further, subsequent epitaxial growth is performed on at least the region where the artificial micro-pits are located, so that the film layer composition of the sidewall of the artificial micro-pit in the first cross-sectional shape on the first reference plane perpendicular to the substrate 101 on the side of the MQW layer 105 facing the subsequent epitaxial layer is different from the film layer composition of the subsequent epitaxial layer in the platform region.

[0074] Alternatively, when the electron blocking layer 106 is used as a stop layer, the second conductive type semiconductor layer 107 is etched from a side of the second conductive type semiconductor layer 107 away from the electron blocking layer 106 to form a plurality of artificial micro-pits, and a platform region is formed around the artificial micro-pits. Further, subsequent epitaxial growth is performed on at least the region where the artificial micro-pits are located, so that the film layer composition of the sidewall of the artificial micro-pit in the first cross-sectional shape on the first reference plane perpendicular to the substrate 101 on the side of the electron blocking layer 106 facing the subsequent epitaxial layer is different from the film layer composition of the subsequent epitaxial layer in the platform region.

[0075] Furthermore, a mask layer may be deposited on the stop layer and patterned to obtain a mask pattern. The mask layer may be an organic photoresist or a SiO 2 、Si 3 N 4 The non-metallic compound may be a metal layer, the deposition method includes but is not limited to chemical vapor deposition, physical vapor deposition, electrochemical deposition, and the patterning method includes but is not limited to dry etching, wet etching and stripping. The mask pattern is used to etch the non-mask area to form a plurality of artificial micro-pits. The etching rate, angle and anisotropy can be adjusted by changing the process parameters, and the depth, cross-sectional shape and sidewall angle of the artificial micro-pits can be controlled.

[0076] Different from the prior art, the artificial micro-pits obtained 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", select any substrate 101 and / or epitaxial layer as the stop layer of the artificial micro-pit, and the film composition of the side wall on the side of the stop layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the platform area, thereby achieving the purpose of regulating the side wall band structure, optimizing the hole injection path, and further reducing the hole injection barrier height, increasing the efficiency and uniformity of the side wall lateral current injection, and improving the luminescence efficiency.

[0077] The specific embodiments of the present application are described in detail below in combination with the technical solutions and drawings.

[0078] Example 1

[0079] like Figure 1 As shown, a substrate 101 is provided, and a buffer layer 102, an N-type GaN layer 103, a pre-well preparation layer 104, and an MQW layer 105 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, and the pit depth of the initial micro-pit is less than the thickness of the MQW layer 105.

[0080] Differential epitaxial growth is performed on the MQW layer 105 in the region where the starting micropit is located and in the peripheral region of the starting micropit. The electron blocking layer 106 and the first P-type semiconductor layer 1071 are sequentially grown in the region where the starting micropit is located, and the electron blocking layer 106 and the second P-type semiconductor layer 1072 are sequentially grown in the peripheral region of the starting micropit. Under the induction of the starting micropit, the electron blocking layer 106 and the first P-type semiconductor layer 1071 grown in the region where the starting micropit are located form induced micropits, and the electron blocking layer 106 and the second P-type semiconductor layer 1072 grown in the peripheral region of the starting micropit form a platform region.

[0081] The starting micropit and the induced micropit cooperate to form an artificial micropit, and the sidewall of the artificial micropit having a first cross-sectional shape on a first reference plane perpendicular to the substrate 101 includes at least the first P-type semiconductor layer 1071 in the film layer on the side of the MQW layer 105 facing the electron blocking layer 106 and the first P-type semiconductor layer 1071, and the first P-type semiconductor layer 1071 at the sidewall is different from the second P-type semiconductor layer 1072 in the platform area.

[0082] Example 2

[0083] like Figure 2 As shown, a substrate 101 is provided, and a buffer layer 102, an N-type GaN layer 103, a pre-well preparation layer 104, and an MQW layer 105 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, and the pit depth of the initial micro-pit is less than the thickness of the MQW layer 105.

[0084] Differential epitaxial growth is performed on the MQW layer 105 in the region where the starting micropit is located and in the peripheral region of the starting micropit, and the custom epitaxial layer 108, the electron blocking layer 106 and the P-type semiconductor layer 107 are sequentially grown in the region where the starting micropit is located, and the electron blocking layer 106 and the P-type semiconductor layer 107 are sequentially grown in the peripheral region of the starting micropit. Under the induction of the starting micropit, the custom epitaxial layer 108, the electron blocking layer 106 and the P-type semiconductor layer 107 grown in the region where the starting micropit are located form induced micropits, and the electron blocking layer 106 and the P-type semiconductor layer 107 grown in the peripheral region of the starting micropit form a platform region.

[0085] The starting micropit and the induced micropit cooperate to form an artificial micropit. The sidewall of the artificial micropit having a first cross-sectional shape on a first reference plane perpendicular to the substrate 101 includes at least a custom epitaxial layer 108 on the film layer on the side of the MQW layer 105 facing the electron blocking layer 106 and the P-type semiconductor layer 107. The custom epitaxial layer 108 at the sidewall is different from the electron blocking layer 106 and the P-type semiconductor layer 107 in the platform area.

[0086] Example 3

[0087] like Figure 3 As shown, a substrate 101 is provided, and a buffer layer 102, an N-type GaN layer 103, a pre-well preparation layer 104, an MQW layer 105, and an electron blocking layer 106 are sequentially stacked on the substrate 101 by epitaxial growth. The electron blocking layer 106 is used as a stop layer, and a portion of the electron blocking layer 106 is removed by an etching process, and a starting micro-pit is formed on the MQW layer 105, and the pit depth of the starting micro-pit is less than the thickness of the MQW layer 105.

[0088] Differential epitaxial growth is performed on the MQW layer 105 in the region where the starting micropit is located and on the electron blocking layer 106 in the peripheral region of the starting micropit, and a P-type semiconductor layer 107 is grown in the region where the starting micropit is located and in the peripheral region of the starting micropit. Under the induction of the starting micropit, an induced micropit is formed in the P-type semiconductor layer 107 grown in the region where the starting micropit is located, and a platform region is formed in the electron blocking layer 106 and the P-type semiconductor layer 107 grown in the peripheral region of the starting micropit.

[0089] The starting micropit and the induced micropit cooperate to form an artificial micropit, and the sidewall of the artificial micropit in the first cross-sectional shape on the first reference plane perpendicular to the substrate 101 only includes the P-type semiconductor layer 107 in the film layer on the side of the MQW layer 105 facing the electron blocking layer 106 and the P-type semiconductor layer 107, and the P-type semiconductor layer 107 at the sidewall is different from the composite layer of the electron blocking layer 106 and the P-type semiconductor layer 107 in the platform area.

[0090] Example 4

[0091] like Figure 4 As shown, a substrate 101 is provided, and a buffer layer 102, an N-type GaN layer 103, a pre-well preparation layer 104, an MQW layer 105, and an electron blocking layer 106 are sequentially stacked on the substrate 101 by epitaxial growth. The electron blocking layer 106 is used as a stop layer, and a portion of the electron blocking layer 106 is removed by an etching process, and a starting micro-pit is formed on the MQW layer 105, and the pit depth of the starting micro-pit is less than the thickness of the MQW layer 105.

[0092] Differential epitaxial growth is performed on the MQW layer 105 in the region where the starting micropit is located and on the electron blocking layer 106 in the peripheral region of the starting micropit, and a custom epitaxial layer 108 and a P-type semiconductor layer 107 are grown in the region where the starting micropit is located, and a P-type semiconductor layer 107 is grown in the peripheral region of the starting micropit. Under the induction of the starting micropit, an induced micropit is formed in the custom epitaxial layer 108 and the P-type semiconductor layer 107 grown in the region where the starting micropit is located, and a platform region is formed in the electron blocking layer 106 and the P-type semiconductor layer 107 grown in the peripheral region of the starting micropit.

[0093] The starting micropit and the induced micropit cooperate to form an artificial micropit, and the sidewall of the artificial micropit having a first cross-sectional shape on a first reference plane perpendicular to the substrate 101 includes a custom epitaxial layer 108 and a P-type semiconductor layer 107 on the side of the MQW layer 105 facing the electron blocking layer 106 and the P-type semiconductor layer 107, and the P-type semiconductor layer 107 at the sidewall is different from the composite layer of the electron blocking layer 106 and the P-type semiconductor layer 107 in the platform area.

[0094] Example 5

[0095] like Figure 5 As shown, a substrate 101 is provided, and a buffer layer 102, an N-type GaN layer 103, a pre-well preparation layer 104, and an MQW layer 105 are sequentially stacked on the substrate 101 by epitaxial growth. The MQW layer 105 is used as a stop layer, and the mask pattern is used to etch the non-mask area to form a plurality of starting micro-pits with different pit depths on the MQW layer 105, and the pit depth of the starting micro-pit is less than the thickness of the MQW layer 105.

[0096] Differentiated epitaxial growth is performed on the MQW layer 105 in the regions where the multiple starting micropits are located and in the peripheral regions of the starting micropits, and the electron blocking layer 106 and the first P-type semiconductor layer 1071 are sequentially grown in the regions where the starting micropits are located, and the electron blocking layer 106 and the second P-type semiconductor layer 1072 are sequentially grown in the peripheral regions of the starting micropits. Under the induction of the starting micropits, the electron blocking layer 106 and the first P-type semiconductor layer 1071 grown in the regions where the starting micropits are located form induced micropits, and the electron blocking layer 106 and the second P-type semiconductor layer 1072 grown in the peripheral regions of the starting micropits form platform regions.

[0097] The starting micropit and the induced micropit cooperate to form an artificial micropit, and the sidewall of the artificial micropit having a first cross-sectional shape on a first reference plane perpendicular to the substrate 101 includes at least the first P-type semiconductor layer 1071 in the film layer on the side of the MQW layer 105 facing the electron blocking layer 106 and the first P-type semiconductor layer 1071, and the first P-type semiconductor layer 1071 at the sidewall is different from the second P-type semiconductor layer 1072 in the platform area.

[0098] Example 6

[0099] like Figure 6 As shown, a substrate 101 is provided, and a buffer layer 102, an N-type GaN layer 103, a pre-well preparation layer 104, and an MQW layer 105 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. The pit depth of the initial micro-pit is greater than the thickness of the MQW layer 105, and an insulating layer 109 is deposited at the bottom of the initial micro-pit to insulate the subsequent epitaxial layer at the area where the initial micro-pit is located from the pre-well preparation layer 104.

[0100] Differential epitaxial growth is performed on the MQW layer 105 in the region where the starting micropit is located and in the peripheral region of the starting micropit. The electron blocking layer 106 and the first P-type semiconductor layer 1071 are sequentially grown in the region where the starting micropit is located, and the electron blocking layer 106 and the second P-type semiconductor layer 1072 are sequentially grown in the peripheral region of the starting micropit. Under the induction of the starting micropit, the electron blocking layer 106 and the first P-type semiconductor layer 1071 grown in the region where the starting micropit are located form induced micropits, and the electron blocking layer 106 and the second P-type semiconductor layer 1072 grown in the peripheral region of the starting micropit form a platform region.

[0101] The starting micropit and the induced micropit cooperate to form an artificial micropit, and the sidewall of the artificial micropit having a first cross-sectional shape on a first reference plane perpendicular to the substrate 101 includes at least the first P-type semiconductor layer 1071 in the film layer on the side of the MQW layer 105 facing the electron blocking layer 106 and the first P-type semiconductor layer 1071, and the first P-type semiconductor layer 1071 at the sidewall is different from the second P-type semiconductor layer 1072 in the platform area.

[0102] Different from the prior art, the artificial micro-pit of the present application uses the substrate 101 and / or at least one of 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 pits", select any substrate 101 and / or epitaxial layer as the stop layer of the artificial micro-pit, and the film composition of the side wall on the side of the stop layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the platform area, thereby achieving the purpose of regulating the side wall band structure, optimizing the hole injection path, and further reducing the hole injection barrier height, increasing the efficiency and uniformity of side wall lateral current injection, and improving the luminescence efficiency.

[0103] 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 in an epitaxial generation manner, 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 into a subsequent epitaxial layer subsequently formed on the stop layer, wherein the artificial micro-pits have two side walls opposite to each other in a first cross-sectional shape on a first reference plane perpendicular to the substrate, and the light-emitting device has a platform region at the periphery of the artificial micro-pits, the subsequent epitaxial layer is at least located in the platform region, wherein the film composition of the sidewall on the side of the stop layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the platform region; 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 is epitaxially generated 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 size of the opening is set so that the cross-sectional shape of the induced micro-pits formed in the epitaxial generation process of the subsequent epitaxial layer on a second reference plane parallel to the substrate is consistent with the cross-sectional shape of the opening on the second reference plane parallel to the substrate.

2. The light emitting device according to claim 1, characterized in that: The number of film layers of the sidewall on the side of the stop layer facing the subsequent epitaxial layer is less than or greater than the number of film layers of the subsequent epitaxial layer in the terrace region.

3. The light emitting device according to claim 1, characterized in that: The film composition of the sidewall on the side of the stop layer facing the subsequent epitaxial layer is different from the film composition of the subsequent epitaxial layer in the terrace region.

4. The light emitting device according to claim 1, characterized in that: The film layer of the sidewall on the side of the stop layer facing the subsequent epitaxial layer includes at least one custom epitaxial layer different from the subsequent epitaxial layer in the terrace region.

5. The light emitting device according to claim 4, characterized in that: The custom epitaxial layer is a carrier injection layer.

6. 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.

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

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

9. 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 .

10. The light emitting device according to claim 1, characterized in that: An intersection angle between at least one of the sidewalls and the substrate is different from an intersection angle between a 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; Differentiated epitaxial growth is performed on the stop layer on the area where the starting micropit is located and the peripheral area of ​​the starting micropit, so that an induced micropit is formed in a subsequent epitaxial layer subsequently grown on the stop layer under the induction effect of the starting micropit, wherein the starting micropit and the induced micropit cooperate to form an artificial micropit, wherein the artificial micropit has two side walls opposite to each other in a first cross-sectional shape on a first reference plane perpendicular to the substrate, and a platform area is formed on the periphery of the artificial micropit, and the film layer composition of the sidewall on the side of the stop layer facing the subsequent epitaxial layer is different from the film layer composition of the subsequent epitaxial layer in the platform area.

Images