Preparation method of gallium nitride-based resonant cavity light-emitting diode and product thereof

Abstract

The invention discloses a preparation method of a gallium nitride-based resonant cavity light-emitting diode and a product of the gallium nitride-based resonant cavity light-emitting diode. The method sequentially comprises the following steps: epitaxially growing a gallium nitride-based epitaxial layer on an original substrate, and preparing a plurality of curved surface structures on one surface of the gallium nitride-based epitaxial layer; sequentially depositing a current expansion layer, a curved surface reflector and a transition layer on the curved surface structure along a first direction, and preparing a regional metal substrate corresponding to the size of the transition layer on the surface of the transition layer of each curved surface structure; placing one side of the regional metal substrate on a temporary substrate, removing the original substrate, and polishing, thinning and planarizing the other surface of the gallium nitride-based epitaxial layer; depositing a plane mirror on the other surface of the gallium nitride-based epitaxial layer, and preparing an electrode; and removing the temporary substrate to obtain the single independent gallium nitride-based resonant cavity light-emitting diode. According to the invention, metal curled edges and side wall damages during obtaining of an independent device can be improved, an experimental process is optimized, and performances of light output power and the like of the device are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gallium nitride-based resonant cavity light emitting diodes, and in particular to a method for preparing a gallium nitride-based resonant cavity light emitting diode. Background Art

[0002] Gallium nitride (GaN) material is an excellent direct bandgap semiconductor material with good thermal stability, high electron migration rate, strong corrosion and radiation resistance, excellent optical and electrical properties, stable chemical and physical properties, etc. In addition, the composite material composed of other gallium nitride-based semiconductor materials, such as aluminum nitride (AlN) and indium nitride (InN), has a continuously adjustable bandgap width between 0.7 and 6.2 eV, and the spectrum covers the infrared to ultraviolet light band. Therefore, it is widely used in semiconductor lighting, high-brightness display, visible light communication, biomedicine, aerospace, microwave radio frequency devices, power devices and other fields.

[0003] At present, resonant cavity light emitting diodes are mostly used to prepare array structures for large-scale integration, but there is a problem that it is difficult to obtain independent devices first and then prepare array structures, such as the previous applications of this research group, such as CN117498146A, a gallium nitride-based vertical cavity surface emitting laser and its preparation method, and CN118137289A, a gallium nitride-based vertical cavity surface emitting laser and its preparation method. Among them, CN117498146A, a gallium nitride-based vertical cavity surface emitting laser and its preparation method, in the curved surface VCSEL preparation method mentioned in the case, its process flow is to first prepare the p-face planar structure, and then prepare the n-face curved surface light emitting surface. The device structure is an n-face curved surface structure emitting light, so when using ICP etching technology to separate the device, it is necessary to etch from N-GaN to P-GaN. Taking the GaN substrate commonly used for preparing curved surfaces as an example, the thickness of N-GaN is generally tens of microns, and the etching thickness is large, which increases the complexity of the process and is easy to damage the device due to long-term etching. At the same time, this case prepared a whole-surface planar supporting substrate. Even if ICP etching technology is used to separate and realize independent testing of single devices, a complete single device structure cannot be realized. All devices are supported by the whole substrate. If mechanical cutting or laser cutting is used to obtain a single independent device, the device will be further damaged, greatly reducing the yield rate.

[0004] CN118137289A is a gallium nitride-based vertical cavity surface emitting laser and its preparation method. The case proposes a method for preparing a curved VCSSEL with p-side light emission. First, a planar light-emitting surface of the p-side is prepared, then a curved surface structure of the n-side is prepared, and finally a planar substrate is prepared on the n-side to support the device. Although the case solves the problem of the difficulty of etching from N-GaN to P-GaN in the previous case, the device is still supported by a whole planar substrate. Only etching technology is used to separate the active areas of different devices to achieve light emission of a single device. All devices share a planar substrate to support the substrate. If a single independent device test or a different array form test is required, mechanical cutting or laser cutting methods are still required. If a planar substrate of different materials is used, it is also necessary to consider whether the substrate can be completely cut from various aspects. The substrate cutting is difficult and it is inevitable to damage the device.

[0005] Therefore, the existing process technology requires mechanical cutting or laser cutting to cut the substrate when obtaining independent devices, which is prone to problems such as metal substrate curling or metal melt spraying onto the device sidewall during multiple slicing. These methods of obtaining independent devices are prone to damage the prepared devices, causing increased device leakage current and reduced yield. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a method for preparing a gallium nitride-based resonant cavity light-emitting diode and its products, which can improve the metal curling and sidewall damage when obtaining an independent device, optimize the experimental process, and improve the device's light output power and other performance.

[0007] According to one aspect of the present invention, a method for preparing a gallium nitride-based resonant cavity light emitting diode is provided, the method comprising the following steps in sequence:

[0008] Epitaxially growing a gallium nitride-based epitaxial layer on an original substrate, preparing a plurality of curved surface structures on a surface of the gallium nitride-based epitaxial layer; sequentially depositing a current spreading layer, a curved surface reflector, and a transition layer along a first direction on the curved surface structure, and preparing a regional metal substrate corresponding to the size of the transition layer on the surface of the transition layer of each curved surface structure;

[0009] Placing one side of the regional metal substrate on a temporary substrate, removing the original substrate and polishing, thinning and flattening the other surface of the gallium nitride-based epitaxial layer; depositing a plane reflector on the other surface of the gallium nitride-based epitaxial layer, and preparing an electrode;

[0010] The temporary substrate is removed to obtain a single independent GaN-based resonant cavity light emitting diode.

[0011] In the above technical solution, a regional metal substrate is prepared, which solves the problem that the whole supporting substrate is difficult to separate to obtain a single independent device in the previous process preparation. By preparing the regional metal substrate, the regional metal substrate does not need to be mechanically cut or laser cut to obtain an independent device after the device is prepared, avoiding the problems of metal substrate curling, device sidewall damage, active area damage, etc. caused by the cutting process, while simplifying the experimental process. The patterned substrate and temporary substrate transfer technology are introduced to achieve self-splitting of the device table and channel after laser stripping. After the device is prepared, the temporary substrate is removed to obtain an independent device. The regional metal substrate not only solves the damage caused by substrate cutting and ICP device separation, but also serves as a substrate support to increase the stability of the overall device structure. It can also be used as a P-side electrode of the device to realize a vertical current injection structure, alleviating current congestion and heat dissipation problems under high current.

[0012] In some embodiments, the reflector is made of metal.

[0013] In the above technical solution, a metal reflector is deposited on the surface of the curved structure, which solves the problem that the DBR is used as a lower reflector, and the poor heat dissipation and conductivity of the device lead to poor overall heat dissipation and difficulty in bearing large current injection. By preparing a curved metal reflector, compared with nitride DBR, dielectric film DBR and hybrid DBR, the metal reflector has good heat dissipation and conductivity. While having a high reflectivity, it can also be used as an electrode conductive layer and improve the ohmic contact characteristics, which is very suitable as a bottom reflector. The preparation process of the metal reflector is simple, the production cost is low, and it has high reflectivity in almost all spectral ranges. In addition, its heat dissipation performance is significantly improved compared to DBR, which is more suitable for the heat dissipation of high-power devices and reduces the impact of the internal temperature of the device on the active area gain and light output power. It should also be noted that the method provided in this case can also be used for nitride DBR, dielectric film DBR, and hybrid DBR, but the subsequent embodiments of this case are described using metal reflectors as an example.

[0014] In some embodiments, the thickness of the reflector is 80-300 nm.

[0015] In the above technical solution, the thickness of the metal reflector deposited on the surface of the curved structure has an optimal thickness range, within which most metal materials have the best reflectivity, which solves the problem that when depositing metal mirrors of different materials, the metal mirror is not dense enough due to the thin thickness or the metal mirror is roughened due to the thick thickness. The curved surface structure metal reflector 32 serves as the lower reflector of the device, which is the other direction of the plane light-emitting reflector. Common metal aluminum mirrors, metal silver mirrors or metal gold mirrors can be selected. The preparation process of the metal reflector is simple and the production cost is low, but each specific metal has its best reflection band. A certain metal reflector can be selected to be deposited according to the light-emitting band of the epitaxial wafer, or a material with a large work function, good conductivity and high reflectivity can be appropriately selected to prepare the metal mirror in combination. At the same time, the thickness of the reflector is different, and its reflectivity also has certain differences. The thickness range of 80-300nm is the optimal thickness for most metal mirrors. The metal material selected for the metal reflector has its optimal reflection band. Different metals need to be selected according to the light-emitting band of the light-emitting device to achieve high reflection in this band. The metal reflector has an optimal thickness range. If the deposited thickness is too thin, the metal mirror will not be dense enough, resulting in increased light transmittance and reduced reflectivity. If the deposited thickness is too thick, the problem of high roughness of the metal mirror will easily occur. It should be noted that the thickness of the metal reflector referred to in this case refers to the deposited thickness deposited on the curved surface structure. Since the reflectivity of metal mirrors of various materials is different in different bands, the Al mirror in the green light band is taken as an example here. When the thickness of the deposited Al mirror is below 80nm, the reflectivity increases significantly with increasing thickness; when the thickness is above 80nm, there is only a slight change in reflectivity with increasing thickness; when the thickness gradually increases, it will not cause a significant decrease in reflectivity, but the roughness of the metal mirror increases, affecting the light output performance of the device. Therefore, the above thickness range is obtained based on the performance of each material.

[0016] In some embodiments, the regional metal substrate is placed on one side on a temporary substrate, specifically:

[0017] The metal base of the region is placed on a temporary substrate by using an adhesive bonding method and / or a temporary substrate transfer method.

[0018] In the above technical solution, the adhesive bonding technology is used to flip the sample and bond it to the temporary substrate, which solves the problem of sample support in the subsequent steps and provides stable support for it without damaging the epitaxial wafer. The adhesive bonding technology used in this case uses an adhesive to bond the epitaxial wafer to the temporary substrate. The bonding and debonding operations are simple, applicable to a variety of materials and structures, and cause little damage to the epitaxial wafer. In addition to adhesive bonding, common technologies for transferring temporary substrates include electrostatic bonding, molecular bonding, thermoplastic polymer bonding, and temporary bonding layer bonding. Electrostatic bonding is to bond the epitaxial wafer and the substrate with electrostatic force. It has very high requirements for the surface flatness of both, and is only applicable to specific materials. It can only be completed under specific experimental conditions and the operation is complicated; molecular bonding is similar to electrostatic bonding, with high requirements for surface treatment and complex bonding and separation processes; thermoplastic polymer bonding uses thermoplastic polymers to soften when heated and form strong bonds when cooled. It is sensitive to temperature and requires precise control of the heating and cooling processes; the temporary bonding layer needs to select appropriate materials to ensure stability and removability in the process.

[0019] In some embodiments, a metal substrate having a region corresponding to the size of the transition layer is prepared on the surface of the transition layer of each curved structure, specifically:

[0020] The transition layer surface is regionalized by photolithography, and then the regional metal substrate is prepared by electroplating, metal bonding, or deposition.

[0021] In the above technical solution, the metal substrate is obtained by first photolithography to realize surface regionalization and then regional electroplating. This step realizes the subsequent epitaxial layer self-splitting, which solves the problems of difficulty in cutting and separation caused by the whole surface support substrate in the previous process preparation. In addition, regional electroplating has the advantages of low cost, high efficiency, high uniformity and strong adhesion, and can flexibly control the thickness of the metal substrate. In addition to electroplating, the metal substrate can also be obtained by metal bonding or metal deposition. However, metal bonding involves high temperature and high pressure equipment, the process is complex and the equipment requirements are high. There are many material restrictions for metal bonding, and strict requirements on the thermal expansion coefficient of the material; the deposition rate of metal deposition is slow, and it is difficult to achieve uniform deposition on complex shapes and large-area substrates.

[0022] According to another aspect of the present invention, a product is provided, which is prepared by the above-mentioned method for preparing a gallium nitride-based resonant cavity light emitting diode.

[0023] In the above technical solution, the regional metal substrate is obtained by using the technology of graphic lithography and regional electroplating, so that the epitaxial wafer can be self-splitting when the substrate is removed later. The metal substrate obtained by electroplating technology has the advantages of good uniformity, fast electroplating rate, high adhesion, etc., and the regionalized metal substrate makes it possible to produce a single independent device without the need to use mechanical cutting or laser cutting and other technologies, avoiding problems such as metal curling or device damage caused by cutting, and greatly improving the yield rate. The use of a metal reflector as a lower reflector not only has a high reflectivity, but can also be used as an electrode conductive layer to improve the ohmic contact characteristics and heat dissipation performance. At the same time, the thickness range of the metal reflector is limited to 80-300nm, providing an optimal thickness range, avoiding problems such as the decline of the metal mirror reflector and the increase of roughness due to too thin or too thick thickness. At the same time, the process preparation flow of this case is to prepare the curved surface structure first and then prepare the related processes of the planar structure. Preparing the curved surface structure first can timely measure the relevant parameters of the curved surface structure, and perform performance testing on the half cavity of the curved surface structure. The performance test results of the curved half cavity can be compared and analyzed with the subsequent complete resonant cavity structure to further improve the device performance characterization. In addition, the preparation of the curved surface structure is much more complicated than the planar structure process. Preparing the complex process first can reduce the risk of failure of the subsequent simple process, thereby reducing the overall preparation cost and improving the controllability of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic structural cross-sectional view of a gallium nitride-based resonant cavity light emitting diode independent device according to a specific embodiment of the present invention;

[0026] Figure 2 is a flow chart of the preparation process of a specific embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of the structure of an epitaxial wafer according to a specific embodiment of the present invention;

[0028] Figure 4 It is a schematic structural diagram of a sample after a curved surface structure is prepared on the surface of P-type gallium nitride in a specific embodiment of the present invention;

[0029] Figure 5 It is a schematic structural diagram of a sample after a current spreading layer and a metal reflector are deposited on a curved gallium nitride surface in a specific embodiment of the present invention;

[0030] Figure 6 is a schematic structural diagram of a sample after depositing a metal substrate seed layer or a bonding layer according to a specific embodiment of the present invention;

[0031] Figure 7 is a schematic structural diagram of a sample after preparing a metal substrate having a region with high thermal conductivity according to a specific embodiment of the present invention;

[0032] Figure 8 It is a schematic diagram of the structure of a specific embodiment of the present invention after the regional metal substrate sample is first reversely bonded to a temporary substrate, the original substrate is removed, and finally the N-type gallium nitride is polished, thinned and flattened;

[0033] Fig. 9 is a schematic structural diagram of a planar reflector 71 prepared on an N-type gallium nitride 12 according to a specific embodiment of the present invention;

[0034] Fig.10 is a schematic structural diagram of a sample after a plane reflector is deposited on the surface of N-type gallium nitride according to a specific embodiment of the present invention; Fig.11 is a schematic diagram of the structure of a sample after preparing an N-side electrode according to a specific embodiment of the present invention; DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below in conjunction with the accompanying drawings and examples. It is particularly noted that the following examples are only used to illustrate the present invention, but are not intended to limit the scope of the present invention. Similarly, the following examples are only partial embodiments of the present invention rather than all embodiments, and all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0036] The present invention provides a method for preparing a gallium nitride-based resonant cavity light-emitting diode and a product thereof, which can improve metal curling and side wall damage when obtaining an independent device, optimize the experimental process, and improve the performance of the device such as the light output power.

[0037] Embodiment 1

[0038] In the implementation part, in order to better understand the subsequent processing technology, this case first starts with the product structure prepared by the preparation method of the gallium nitride-based resonant cavity light-emitting diode, as follows:

[0039] See also Figure 1 The gallium nitride-based resonant cavity light-emitting diode independent device includes: a metal substrate 51, a metal substrate seed layer or bonding layer 41, a curved surface structure metal reflector 32, a current spreading layer 31, a P-type layer 14, an active region 13 and an N-type layer 12, and a plane reflector 71 and an N-electrode 81 arranged on the N-type layer.

[0040] Furthermore, the metal substrate 51 is used to support the gallium nitride-based resonant cavity light-emitting diode, has mechanical stability, and serves as the P-side electrode of the light-emitting device, and has high thermal conductivity and high electrical conductivity; the curved metal reflector 32, compared with the planar structure Bragg reflector, enhances light focusing, reduces diffraction loss and absorption loss in the resonant cavity, enhances heat dissipation, can be used as an electrode conductive layer and form an ohmic contact, etc.; the P-type layer 14, active area 13 and N-type layer 12 constitute a PIN structure, which serves as the light-emitting layer of the device for emitting light.

[0041] In this embodiment, the metal substrate 51 needs to be made of a material with high thermal conductivity and high electrical conductivity to improve the heat dissipation of the device and realize the vertical injection of current. Its thermal conductivity should be no less than 100 Wm / K and its electrical conductivity should be no less than 7×10 6 S / m, thickness range is 20-600μm, it is a flat shaped hard material to support the device and enhance the stability of the supported device;

[0042] Furthermore, in order to enhance the adhesion between the metal substrate and the epitaxial layer, the seed layer or bonding layer 41 of the metal substrate can be connected by magnetron sputtering a seed layer with better adhesion performance or by eutectic bonding, metal bonding, etc.

[0043] In this embodiment, the curved metal reflector 32 is used as the lower reflector of the device, which is the other direction of the plane light-emitting reflector. Common metal aluminum mirrors, metal silver mirrors or metal gold mirrors can be selected. The preparation process of the metal reflector is simple and the production cost is low, but each specific metal has its best reflection band. You can choose to deposit a certain metal reflector according to the light-emitting band of the epitaxial wafer, or appropriately select materials with large work function, good conductivity and high reflectivity to prepare the metal mirror. At the same time, the thickness of the reflector is different, and its reflectivity also has certain differences. The thickness range of 80-300μm is the optimal thickness for most metal mirrors.

[0044] In this embodiment, as a possible material selection scheme, the current spreading layer 31 can select any one of transparent conductive materials such as indium tin oxide, zinc oxide, graphene, etc.; the upper plane reflector 71 can select nitride DBR, dielectric film DBR or hybrid DBR; the N-side electrode 81 can select materials with excellent conductive properties such as Cr / Au, Ni / Au or Ti / Au.

[0045] Embodiment 2

[0046] The specific preparation method is described based on the structure described in one of the embodiments, as follows:

[0047] See also Figure 2, a process flow of a method for preparing a gallium nitride-based resonant cavity light-emitting diode is as follows:

[0048] S1, epitaxially growing a gallium nitride-based epitaxial layer on an original substrate;

[0049] Specifically, the step S1 includes: Figure 3 As shown, an epitaxial layer with a PIN structure is grown by metal organic chemical device deposition (MOCVD) or molecular beam epitaxy (MBE), and an N-type gallium nitride epitaxial layer 12, an active area 13, and a P-type gallium nitride epitaxial layer 14 are grown in sequence on an original substrate 11.

[0050] S2, preparing a curved surface structure on the surface of the P-type gallium nitride layer;

[0051] Specifically, the step S2 includes: Figure 4 As shown, a patterned curved mask is first prepared by a photolithography process, and then the P-GaN without the mask is corroded or etched away by a wet or dry etching process, so as to obtain a curved structure 21 with a specific curvature radius.

[0052] S3, depositing a current spreading layer and a metal reflector on the curved GaN surface;

[0053] Specifically, the step S3 includes: Figure 5 As shown, a current spreading layer 31 is first deposited on the surface of the P-type gallium nitride on which the curved structure 21 has been etched. It is generally indium tin oxide (ITO) formed by a mixture of 90% In2O3 and 10% SnO2, or other transparent conductive materials such as zinc oxide (ZnO) and graphene, and then a metal reflector 32 is deposited. Among them, the metal material selected for the metal reflector has its best reflection band, and different metals need to be selected according to the light-emitting band of the light-emitting device to achieve high reflection in this band; the metal reflector has an optimal thickness range. If the deposited thickness is too thin, the metal mirror is not dense enough, resulting in increased light transmittance and reduced reflectivity. If the deposited thickness is too thick, the problem of high roughness of the metal mirror is likely to occur.

[0054] S4, depositing a seed layer or a bonding layer;

[0055] Specifically, the step S4 includes: Figure 6 As shown, in order to enhance the adhesion of the metal substrate, a seed layer or bonding layer 32 needs to be deposited before preparing the metal substrate to enhance the adhesion of the metal substrate. Generally speaking, the material selected for the seed layer is Cr / Au, Ni / Au, Ti / Au, etc. with high conductivity, and the material selected for the bonding layer is In / Au, Sn / Au, etc., an alloy with a low melting point.

[0056] S5. preparing a regional metal substrate having high thermal conductivity and electrical conductivity;

[0057] Specifically, the step S5 includes: Figure 7 As shown, for the regional metal substrate, if electroplating technology is used, it is necessary to first use a photolithography process to use thick photoresist on the seed layer or bonding layer to achieve graphic regionalization, and then prepare the regional metal substrate 51 through electroplating, metal bonding or deposition.

[0058] S6, regional metal substrate, first invert the sample and bond it to a temporary substrate, then laser lift off and polish;

[0059] Specifically, the step S6 includes: Figure 8 As shown, for the regional metal substrate 51, it is first transferred to the temporary substrate 61 using photosensitive adhesive, high temperature and high pressure bonding adhesive, high temperature resistant wax, etc., and then the original substrate 11 is removed by laser stripping or wet etching technology. At this time, the channel without metal substrate support breaks and falls, thereby realizing the self-splitting of the table, and then CMP is used to thin and flatten the N-GaN. In this embodiment, the temporary substrate is a hard substrate that can provide support, and the temporary substrate is generally not reusable and is a disposable substrate. A low-cost quartz sheet is generally selected for experiments. Because after the original substrate is removed, the contact part between the original substrate and the epitaxial wafer will be uneven due to the removal of the substrate, and the surface is relatively rough, which greatly affects the subsequent process preparation and the light-emitting performance of the device, so the flattening here refers to the use of polishing technology to polish the surface to a flat surface, which is an indispensable step in the process preparation.

[0060] S7, depositing a plane reflector on the surface of N-type gallium nitride;

[0061] Specifically, the step S7 includes: Fig. 9 As shown, a plane reflector 71 is prepared on the N-type gallium nitride 12, and a plane DBR reflector is prepared by processes such as evaporation or sputtering. Since the preparation cost of nitride DBR is high and the high reflection band width is narrow, the light-emitting surface DBR mostly uses a dielectric film DBR that is grown by overlapping materials with high and low refractive indices.

[0062] S8, preparing N-side electrode;

[0063] Specifically, the step S8 includes: Fig.10 As shown, an N-side electrode 81 is prepared on the N-type gallium nitride 12. The electrode needs to have high electrical conductivity. The above material selection scheme has specifically given possible material selections, so it will not be repeated here.

[0064] S9, obtaining independent devices;

[0065] Specifically, the step S9 includes: removing the temporary substrate 61 by using acetone, a debonding agent or other solvents, so that a single independent device can be obtained, such as Figure 1 As shown, the device preparation is completed.

[0066] The above descriptions are only some embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any equivalent device or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a gallium nitride-based resonant cavity light-emitting diode, characterized in that: The method comprises the following steps in sequence: Epitaxially growing a gallium nitride-based epitaxial layer on an original substrate, and preparing a plurality of curved surface structures on a surface of the gallium nitride-based epitaxial layer; sequentially depositing a current spreading layer, a reflector, and a transition layer on the curved surface structure along a first direction, and preparing a regional metal substrate corresponding to the size of the transition layer on the surface of the transition layer of each curved surface structure; Placing one side of the regional metal substrate on a temporary substrate, removing the original substrate and polishing, thinning and flattening the other surface of the gallium nitride-based epitaxial layer; Depositing a plane reflector on the other surface of the gallium nitride-based epitaxial layer and preparing an electrode; The temporary substrate is removed to obtain a single independent GaN-based resonant cavity light emitting diode.

2. The method for preparing a gallium nitride-based resonant cavity light-emitting diode according to claim 1, characterized in that: The reflector is made of metal.

3. The method for preparing a gallium nitride-based resonant cavity light-emitting diode according to claim 1, characterized in that: The reflector is a nitride DBR, a dielectric film DBR, or a hybrid DBR.

4. A method for preparing a gallium nitride-based resonant cavity light-emitting diode according to any one of claims 1 to 3, characterized in that: The thickness of the reflector is 80-300 nm.

5. The method for preparing a gallium nitride-based resonant cavity light-emitting diode according to claim 1, characterized in that: The metal base of the region is placed on a temporary substrate, specifically: The metal base of the region is placed on a temporary substrate by using an adhesive bonding method and / or a temporary substrate transfer method.

6. The method for preparing a gallium nitride-based resonant cavity light-emitting diode according to claim 1, characterized in that: A metal substrate having a region corresponding to the size of the transition layer is prepared on the surface of the transition layer of each curved structure, specifically: The transition layer surface is regionalized by photolithography, and a regional metal substrate is prepared by electroplating, metal bonding, or deposition.

7. A product, characterized in that The gallium nitride-based resonant cavity light-emitting diode is prepared by the preparation method of any one of claims 1 to 6.

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