Light-emitting diode and light-emitting diode preparation method

Abstract

The invention provides a light emitting diode and a light emitting diode preparation method. The light-emitting diode comprises an epitaxial structure, a silver mirror structure, an epitaxial protection layer and a dielectric film reflection layer, the epitaxial structure is of a step structure; the epitaxial protection layer and the dielectric film reflection layer are sequentially stacked on the step structure, and the epitaxial protection layer and the dielectric film reflection layer are correspondingly provided with through holes in the surface of the epitaxial structure; and the silver mirror structure is located on the dielectric film reflecting layer and is connected with the epitaxial structure through the through hole. The step structure is covered with the epitaxial protection layer, so that the epitaxial structure and the dielectric film reflection layer are isolated, damage to the side wall of a quantum well in the epitaxial structure caused by high-concentration plasma in the manufacturing process of the dielectric film reflection layer is avoided, and the problem that the light-emitting diode is prone to slight electric leakage due to damage to the side wall of the quantum well is solved. And the yield of the light-emitting diode is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of light-emitting devices, and in particular to a light-emitting diode and a method for preparing the light-emitting diode. Background Art

[0002] Light Emitting Diode (LED) is a semiconductor device that can emit light. It has the advantages of energy saving, high brightness, high durability, long life and light weight. It has been widely used in two major fields: backlight display and direct display.

[0003] The related technology provides a light emitting diode, which includes an epitaxial structure, a silver mirror structure, a dielectric film reflective layer, and the like.

[0004] The light emitting diode of the above structure is prone to slight leakage, which affects the yield of the light emitting diode. Summary of the invention

[0005] The embodiments of the present disclosure provide a light emitting diode and a method for manufacturing the light emitting diode, which can solve the slight leakage problem of the light emitting diode and improve the yield of the light emitting diode. The technical solution is as follows:

[0006] In one aspect, a light emitting diode is provided, the light emitting diode comprising: an epitaxial structure, a silver mirror structure, an epitaxial protection layer and a dielectric film reflective layer;

[0007] The epitaxial structure is a step structure; the epitaxial protection layer and the dielectric film reflective layer are sequentially stacked on the step structure, and the epitaxial protection layer and the dielectric film reflective layer are correspondingly provided with through holes on the surface of the epitaxial structure; the silver mirror structure is located on the dielectric film reflective layer and is connected to the epitaxial structure through the through holes.

[0008] Optionally, the epitaxial protective layer is an atomic layer deposited epitaxial protective layer.

[0009] Optionally, the epitaxial protection layer is an Al2O3 thin film layer.

[0010] Optionally, the epitaxial protection layer has a thickness of 50 to 500 angstroms.

[0011] Optionally, the projection of the through hole of the epitaxial protection layer on the surface of the epitaxial structure and the projection of the through hole of the dielectric film reflective layer on the surface of the epitaxial structure are concentric circles.

[0012] In another aspect, a method for preparing a light emitting diode is provided, the method comprising:

[0013] Fabricating epitaxial structures;

[0014] Performing a patterning process on the epitaxial structure to form a step structure;

[0015] An epitaxial protection layer and a dielectric film reflection layer are sequentially stacked on the surface of the step structure, wherein the epitaxial protection layer and the dielectric film reflection layer are provided with through holes correspondingly on the surface of the epitaxial structure;

[0016] A silver mirror structure is manufactured on the dielectric film reflective layer, and the silver mirror structure is connected to the epitaxial structure through the through hole.

[0017] Optionally, manufacturing the epitaxial protection layer includes:

[0018] A first precursor H2O is introduced, wherein the first precursor H2O is adsorbed on the surface of the step structure;

[0019] Use N2 flushing;

[0020] A second precursor, trimethylaluminum, is introduced to react chemically with the first precursor to form an Al2O3 film with a thickness of one atomic layer;

[0021] Flush with N2 again;

[0022] Repeat the above steps for multiple cycles until the thickness of the Al2O3 film reaches the required value, thereby obtaining the epitaxial protective layer.

[0023] Optionally, the temperature during preparation of the epitaxial protective layer is 200-260°C.

[0024] Optionally, the epitaxial protection layer has a thickness of 50 to 500 angstroms.

[0025] Optionally, the projection of the through hole of the epitaxial protection layer on the surface of the epitaxial structure and the projection of the through hole of the dielectric film reflective layer on the surface of the epitaxial structure are concentric circles.

[0026] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:

[0027] In the disclosed embodiment, an epitaxial protective layer is used to cover the step structure, thereby isolating the epitaxial structure and the dielectric film reflective layer, thereby preventing high-concentration plasma in the dielectric film reflective layer from damaging the quantum well side walls in the epitaxial structure, thereby preventing the light-emitting diode from being prone to slight leakage due to damage to the quantum well side walls, thereby improving the yield of the light-emitting diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 is a structural schematic diagram of a light emitting diode provided by an embodiment of the present disclosure;

[0030] Figure 2 is a flow chart of a method for preparing a light emitting diode provided by an embodiment of the present disclosure;

[0031] Figure 3 This is a flow chart of another method for preparing a light emitting diode provided in an embodiment of the present disclosure.

[0032] The reference numerals are as follows:

[0033] 10: epitaxial structure; 20: silver mirror structure; 30: insulating structure; 40: first electrode structure; 50: second electrode structure; 60: epitaxial protection layer; 70: dielectric film reflection layer; 670: through hole; 671: connecting through hole;

[0034] 100: substrate; 101: first semiconductor layer; 102: active layer; 103: second semiconductor layer; 104: transparent conductive layer; 105: reflective layer; 106: protective layer; 107: first electrode; 108: first electrode pad; 109: first insulating layer; 110: second insulating layer; 111: second electrode; 112: second electrode pad; 113: first insulating layer through hole; 114: second insulating layer through hole; 115: step structure; 116: isolation groove. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0036] Figure 1 A schematic diagram of the structure of a light emitting diode provided by an embodiment of the present disclosure. Figure 1 The light emitting diode comprises: an epitaxial structure 10 , a silver mirror structure 20 , an epitaxial protection layer 60 and a dielectric film reflective layer 70 .

[0037] The epitaxial structure 10 is in a step structure 115; the epitaxial protection layer 60 and the dielectric film reflective layer 70 are sequentially stacked on the step structure 115, and the epitaxial protection layer 60 and the dielectric film reflective layer 70 are correspondingly provided with through holes 670 on the surface of the epitaxial structure 10; the silver mirror structure 20 is located on the dielectric film reflective layer 70, and is connected to the epitaxial structure 10 through the through holes 670, that is, the silver mirror structure 20 passes through the dielectric film reflective layer 70 and the epitaxial protection layer 60 to be connected to the epitaxial structure 10.

[0038] In the disclosed embodiment, an epitaxial protective layer is used to cover the step structure, thereby isolating the epitaxial structure and the dielectric film reflective layer, thereby preventing high-concentration plasma in the dielectric film reflective layer from damaging the quantum well side walls in the epitaxial structure, thereby preventing the light-emitting diode from being prone to slight leakage due to damage to the quantum well side walls, thereby improving the yield of the light-emitting diode.

[0039] like Figure 1 As shown, the light emitting diode may further include a substrate 100 , and the epitaxial structure 10 is located on the substrate 100 .

[0040] In the embodiment of the present disclosure, the epitaxial structure 10 includes a first semiconductor layer 101, an active layer 102, and a second semiconductor layer 103. The first semiconductor layer 101, the active layer 102, and the second semiconductor layer 103 are sequentially stacked on a substrate 100. The first semiconductor layer 101, the active layer 102, and the second semiconductor layer 103 are provided with a step structure 115 extending to the first semiconductor layer 101, that is, the step surface is located in the first semiconductor layer 101. The first semiconductor layer 101, the active layer 102, and the second semiconductor layer 103 are also provided with an isolation trench (ISO) 116 extending to the substrate 100, that is, the bottom of the isolation trench 116 is located in the substrate 100.

[0041] The epitaxial protection layer 60 and the dielectric film reflective layer 70 both cover the step structure and the isolation groove.

[0042] like Figure 1 As shown, the light emitting diode may further include a transparent conductive layer 104 , and the transparent conductive layer 104 is located between the second semiconductor layer 103 and the epitaxial protection layer 60 .

[0043] like Figure 1 As shown, the light emitting diode may further include an insulating structure 30 , a first electrode structure 40 and a second electrode structure 50 .

[0044] The insulating structure 30 covers the silver mirror structure 20 and the dielectric film reflective layer 70; the first electrode structure 40 passes through the insulating structure 30 to be connected to the silver mirror structure 20; the second electrode structure 50 passes through the insulating structure 30, the dielectric film reflective layer 70 and the epitaxial protection layer 60 to be connected to the step surface of the step structure 115.

[0045] In the embodiment of the present disclosure, the silver mirror structure 20 includes a reflective layer 105 and a protective layer 106 .

[0046] like Figure 1 As shown, the reflective layer 105 and the protective layer 106 are sequentially stacked on the dielectric film reflective layer 70 , the reflective layer 105 is connected to the transparent conductive layer 104 through the through hole 670 , and the protective layer 106 wraps the reflective layer 105 .

[0047] In the embodiment of the present disclosure, the insulation structure 30 includes a first insulation layer 109 and a second insulation layer 110 .

[0048] like Figure 1 As shown, the first insulating layer 109 covers the silver mirror structure 20 and the dielectric film reflective layer 70, and the first insulating layer 109 respectively opens a first insulating layer through hole 113 at the silver mirror structure 20 and the step surface of the step structure 115, and the epitaxial protection layer 60 and the dielectric film reflective layer 70 open a connecting through hole 671 at the step surface of the step structure 115.

[0049] In the embodiment of the present disclosure, the first electrode structure 40 includes a first electrode 107 and a first electrode pad 108 , and the second electrode structure 50 includes a second electrode 111 and a second electrode pad 112 .

[0050] The first electrode 107 is connected to the protective layer 106 through the first insulating layer through hole 113 at the silver mirror structure 20 , and the second electrode 111 is connected to the first semiconductor layer 101 through the first insulating layer through hole 113 at the step surface of the step structure 115 and the connecting through hole 671 .

[0051] The second insulating layer 110 covers the first electrode 107, the second electrode 111 and the first insulating layer 109. The second insulating layer 110 respectively defines second insulating layer through holes 114 at the first electrode 107 and the second electrode 111. The first electrode pad 108 is connected to the first electrode 107 via the second insulating layer through hole 114 at the first electrode 107. The second electrode pad 112 is connected to the second electrode 111 via the second insulating layer through hole 114 at the second electrode 111.

[0052] In the embodiment of the present disclosure, the substrate 100 may be any one of substrates such as a sapphire substrate, a Si substrate, and a SiC substrate, and the embodiment of the present disclosure does not limit the material of the substrate 100.

[0053] Exemplarily, the substrate 100 is a sapphire substrate.

[0054] In the embodiment of the present disclosure, the first semiconductor layer 101 may be an N-type semiconductor layer, and the second semiconductor layer 103 may be a P-type semiconductor layer.

[0055] For example, the first semiconductor layer 101 may be an N-type GaN layer, and the second semiconductor layer 103 may be a P-type GaN layer.

[0056] In this implementation, the first electrode structure 40 is connected to the silver mirror structure 20 through the insulating structure 30, and the silver mirror structure 20 is connected to the P-type GaN layer through the dielectric film reflective layer 70 and the epitaxial protection layer 60; the second electrode structure 50 is connected to the N-type GaN layer through the insulating structure 30, the dielectric film reflective layer 70 and the epitaxial protection layer 60.

[0057] In other embodiments, the first semiconductor layer 101 may be a P-type semiconductor layer, and the second semiconductor layer 103 may be an N-type semiconductor layer.

[0058] In the embodiment of the present disclosure, the active layer 102 may be a multi-quantum well layer, such as an InGaN / GaN multi-quantum well layer.

[0059] In the embodiment of the present disclosure, the transparent conductive layer 104 may be an indium tin oxide (ITO) layer.

[0060] For example, the thickness of the transparent conductive layer 104 may be 170 to 250 angstroms. If the transparent conductive layer 104 is too thick, it will absorb light and reduce the light extraction rate. If the transparent conductive layer 104 is too thin, it will cause the ohmic contact effect with the semiconductor and the current expansion performance to deteriorate.

[0061] In the embodiment of the present disclosure, the reflective layer 105 is a silver mirror layer, and the reflective layer 105 can be a combination of one or more metal or alloy layers such as Ag, Ni, Ti, TiW, Cr, Al, AlCu, Ti, Ni, Pt, and Au.

[0062] Exemplarily, the reflective layer 105 is a stack of Ag, Ni, Ti and TiW, wherein the metal Ag is the main structure and plays the role of light reflection and current expansion, and Ni, TiW and the like play the role of preventing the migration and diffusion of the metal silver.

[0063] In the embodiment of the present disclosure, the protection layer 106 may be a combination of one or more metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt and Au.

[0064] Exemplarily, the protection layer 106 is a stack of Cr, Al, AlCu, Ti, Ni, Pt, and Au.

[0065] In the embodiment of the present disclosure, the first insulating layer 109 and the second insulating layer 110 may be a distributed Bragg reflector (DBR) layer or a SiO 2 layer, and the DBR layer is a stacked layer formed by SiO 2 and Ti 3 O 5 .

[0066] In the embodiment of the present disclosure, the first electrode 107 and the second electrode 111 may be a combination of one or more metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt and Au.

[0067] Exemplarily, the first electrode 107 and the second electrode 111 are stacked layers of Cr, Al, AlCu, Ti, Ni, Pt, and Au.

[0068] In the embodiment of the present disclosure, the first electrode pad 108 and the second electrode pad 112 may be a combination of one or more metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt, Au, and AuSn.

[0069] Exemplarily, the first electrode pad 108 and the second electrode pad 112 are stacked layers of Cr, Al, AlCu, Ti, Ni, Pt, Au, and AuSn.

[0070] In the embodiment of the present disclosure, the epitaxial protection layer 60 is an epitaxial protection layer deposited by atomic layer deposition (ALD).

[0071] In this implementation, the atomic layer deposition process can ensure that the epitaxial protection layer 60 isolates the epitaxial structure and the dielectric film reflective layer, and the thin thickness does not affect the state size of the light-emitting diode. In addition, atomic layer deposition is a chemical adsorption and self-limiting reaction, and no plasma is generated during the deposition process, thereby avoiding plasma bombardment damage to the quantum well sidewall.

[0072] In a possible implementation of the embodiment of the present disclosure, the epitaxial protection layer 60 may be an Al 2 O 3 thin film layer.

[0073] In this implementation, the Al2O3 thin film layer formed by the ALD process has high density, no pinholes, excellent three-dimensional conformality, and good step coverage. It is an excellent barrier layer and insulating layer that can better isolate the epitaxial structure and the dielectric film reflective layer.

[0074] In the embodiment of the present disclosure, the thickness of the epitaxial protection layer 60 may be 50 to 500 angstroms.

[0075] By way of example, the thickness of the epitaxial protection layer 60 may be 100 to 300 angstroms.

[0076] In this implementation, using the epitaxial protective layer with the above thickness can ensure the reliability of the epitaxial protective layer on the one hand, and on the other hand, the epitaxial protective layer with the above thickness has a low cost.

[0077] In the embodiment of the present disclosure, the dielectric film reflective layer 70 may be a DBR layer or a SiO 2 layer.

[0078] In the embodiment of the present disclosure, the projection of the through hole 670 of the epitaxial protection layer 60 on the surface of the epitaxial structure 10 and the projection of the through hole 670 of the dielectric film reflective layer 70 on the surface of the epitaxial structure 10 are concentric circles.

[0079] In this implementation, the through holes opened in the epitaxial protection layer 60 and the dielectric film reflective layer 70 are circular in design, and the two are concentrically designed, which is convenient for processing and is conducive to better connection between the silver mirror structure and the epitaxy through the through hole to ensure electrical transmission performance.

[0080] like Figure 1 As shown, the projection of the through hole 670 of the epitaxial protection layer 60 on the surface of the epitaxial structure 10 is smaller than the projection of the through hole 670 of the dielectric film reflective layer 70 on the surface of the epitaxial structure 10, that is, the projection of the through hole 670 of the epitaxial protection layer 60 on the surface of the epitaxial structure 10 is located within the projection of the through hole 670 of the dielectric film reflective layer 70 on the surface of the epitaxial structure 10. This through hole design facilitates the opening of through holes.

[0081] In the disclosed embodiment, there are multiple through holes 670 , and the through holes 670 of the epitaxial protection layer 60 correspond one to one with the through holes 670 of the dielectric film reflective layer 70 . The aforementioned relationship refers to the relationship between the corresponding through holes in the two layers.

[0082] It is worth noting that in the embodiments of the present disclosure, structures may be selectively increased or decreased based on the structure of the above-mentioned light emitting diode, and the present disclosure does not impose any limitation on this.

[0083] Figure 2 A flow chart of a method for preparing a light emitting diode provided in an embodiment of the present disclosure. Figure 2 The method steps include:

[0084] S11. Fabricating an epitaxial structure.

[0085] S12, performing a patterning process on the epitaxial structure to form a step structure.

[0086] S13, manufacturing an epitaxial protection layer and a dielectric film reflection layer stacked in sequence on the surface of the step structure, wherein the epitaxial protection layer and the dielectric film reflection layer are provided with through holes correspondingly on the surface of the epitaxial structure.

[0087] S14, manufacturing a silver mirror structure on the dielectric film reflective layer, wherein the silver mirror structure is connected to the epitaxial structure through the through hole.

[0088] In the disclosed embodiment, an epitaxial protective layer is used to cover the step structure, thereby isolating the epitaxial structure and the dielectric film reflective layer, thereby preventing high-concentration plasma in the dielectric film reflective layer from damaging the quantum well side walls in the epitaxial structure, thereby preventing the light-emitting diode from being prone to slight leakage due to damage to the quantum well side walls, thereby improving the yield of the light-emitting diode.

[0089] Figure 3 Another light emitting diode manufacturing method provided by the present disclosure is a flow chart. Figure 3 The method steps include:

[0090] S21. Forming a first semiconductor layer, an active layer, and a second semiconductor layer in sequence on a substrate, wherein the second semiconductor layer, the active layer, and the first semiconductor layer constitute an epitaxial structure.

[0091] The substrate may be any one of a sapphire substrate, a Si substrate, a SiC substrate and the like.

[0092] Exemplarily, the substrate is a sapphire substrate.

[0093] In one example, step S21 includes:

[0094] The first step is to make the first semiconductor layer.

[0095] In the embodiment of the present disclosure, the first semiconductor layer is an N-type GaN layer.

[0096] For example, a Metal Organic Chemical Vapor Deposition (MOCVD) device is used to grow an N-type GaN layer on the surface of a substrate.

[0097] In the disclosed embodiment, the growth of the semiconductor layer can be achieved by using Veeco K465i or C4 or RB MOCVD equipment or AIXTRON metal organic compound chemical vapor deposition equipment. High purity H2 (hydrogen) or high purity N2 (nitrogen) or a mixture of high purity H2 and high purity N2 is used as a carrier gas, high purity NH3 is used as an N source, trimethyl gallium (TMGa) and triethyl gallium (TEGa) are used as gallium sources, trimethyl indium (TMIn) is used as an indium source, silane (SiH4) is used as an N-type dopant, trimethyl aluminum (TMAl) is used as an aluminum source, and bis(cyclopentadienyl) magnesium (CP2Mg) is used as a P-type dopant.

[0098] The second step is to make the active layer.

[0099] In the embodiment of the present disclosure, the active layer is a multi-quantum well layer, such as an InGaN / GaN multi-quantum well layer.

[0100] The third step is to make the second semiconductor layer.

[0101] In the embodiment of the present disclosure, the second semiconductor layer is a P-type GaN layer.

[0102] In the embodiment of the present disclosure, the first semiconductor layer, the active layer, and the second semiconductor layer are sequentially stacked on the substrate.

[0103] S22, performing graphic processing on the epitaxial structure to form a step structure and an isolation groove.

[0104] In the disclosed embodiment, the first semiconductor layer, the active layer, and the second semiconductor layer are provided with a step structure extending to the first semiconductor layer, that is, the step surface is located in the first semiconductor layer. The first semiconductor layer, the active layer, and the second semiconductor layer are also provided with an isolation groove extending to the substrate, that is, the bottom of the isolation groove is located in the substrate.

[0105] S23. Forming a transparent conductive layer on the surface of the epitaxial structure.

[0106] Wherein, the transparent conductive layer is located between the second semiconductor layer and the epitaxial protection layer.

[0107] In the embodiment of the present disclosure, the transparent conductive layer may be an ITO layer.

[0108] For example, the thickness of the transparent conductive layer may be 170 to 250 angstroms. If the transparent conductive layer is too thick, it will cause light absorption and reduce the light extraction rate. If the transparent conductive layer is too thin, it will cause the ohmic contact effect with the semiconductor and the current expansion performance to deteriorate.

[0109] Exemplarily, step S23 may include:

[0110] An ITO film is formed on the surface of the second semiconductor layer by using magnetron sputtering technology; a photoresist mask pattern is formed on the ITO film; and under the shielding of the photoresist mask pattern, an ITO etching solution is used for patterning to form an ITO layer.

[0111] It should be noted that if a photoresist mask pattern is used in the method provided in the embodiment of the present disclosure, a stripping step is also included after use, which will not be described in detail here.

[0112] S24, forming an epitaxial protective layer on the surface of the step structure, wherein the epitaxial protective layer covers the transparent conductive layer, the step structure and the isolation groove.

[0113] In the embodiment of the present disclosure, the epitaxial protection layer is an ALD epitaxial protection layer.

[0114] In this implementation, the atomic layer deposition process is used to ensure that the epitaxial protection layer isolates the epitaxial structure and the dielectric film reflective layer, and the thin thickness does not affect the state size of the light emitting diode.

[0115] In a possible implementation of the embodiment of the present disclosure, the epitaxial protection layer may be an Al2O3 thin film layer.

[0116] In this implementation, the Al2O3 thin film layer formed by the ALD process has high density, no pinholes, excellent three-dimensional conformality, and good step coverage. It is an excellent barrier layer and insulating layer that can better isolate the epitaxial structure and the dielectric film reflective layer.

[0117] In the embodiment of the present disclosure, the thickness of the epitaxial protection layer may be 50 to 500 angstroms.

[0118] Exemplarily, the thickness of the epitaxial protection layer may be 100 to 300 angstroms.

[0119] In this implementation, using the epitaxial protective layer with the above thickness can ensure the reliability of the epitaxial protective layer on the one hand, and on the other hand, the epitaxial protective layer with the above thickness has a low cost.

[0120] Exemplarily, step S24 may include:

[0121] The first step is to control the temperature of the ALD equipment at 200-260°C;

[0122] Illustratively, the temperature is 230°C.

[0123] In the second step, the first precursor H2O (gaseous state) is introduced, and the first precursor H2O is adsorbed on the surface of the light-emitting diode.

[0124] The first precursor, H2O, is used to provide an oxygen source.

[0125] The third step is to flush with N2.

[0126] After washing, except for a layer of H2O adsorbed on the surface of the light-emitting diode, the rest of the H2O is washed away.

[0127] In the fourth step, a second precursor, trimethylaluminum (TMA) (gaseous state), is introduced to chemically react with the first precursor to generate an Al2O3 film with a thickness of an atomic layer.

[0128] The second precursor, trimethylaluminum, is used to provide an Al source.

[0129] Step 5: Flush with N2 again.

[0130] After flushing, excess trimethylaluminum gas and reaction by-products are removed.

[0131] Step 6: Repeat steps 2 to 5, one cycle at a time, and repeat until the film grows to a specified thickness. The film thickness increases by 0.9 to 1.2 angstroms after each cycle.

[0132] Wherein, the thickness of the Al2O3 film layer is 50 to 500 angstroms.

[0133] Exemplarily, the Al2O3 thin film layer has a thickness of 300 angstroms.

[0134] The epitaxial protection layer is prepared by adopting the above environment and steps. The atomic layer deposition is a chemical adsorption and self-limiting reaction. No plasma is generated during the deposition process, thus avoiding plasma bombardment damage to the quantum well side wall.

[0135] S25, forming a dielectric film reflective layer on the surface of the epitaxial protective layer, wherein the dielectric film reflective layer covers the epitaxial protective layer.

[0136] In the embodiment of the present disclosure, the dielectric film reflective layer may be a DBR layer or a SiO2 layer.

[0137] When the dielectric film reflective layer is a SiO2 layer, the dielectric film reflective layer can be deposited and manufactured by using a plasma enhanced chemical vapor deposition (PECVD) device.

[0138] When the dielectric film reflective layer is a DBR layer, the dielectric film reflective layer can be manufactured by using an optical coating machine.

[0139] S26. Opening through holes on the epitaxial protection layer and the dielectric film reflective layer, wherein the through holes correspond to the surface of the epitaxial structure.

[0140] In the embodiment of the present disclosure, the projection of the through hole of the epitaxial protection layer on the surface of the epitaxial structure and the projection of the through hole of the dielectric film reflective layer on the surface of the epitaxial structure are concentric circles.

[0141] In this implementation, the through holes opened in the epitaxial protection layer and the dielectric film reflective layer are circular in design, and the two are concentrically designed, which is convenient for the processing and is conducive to better connection between the silver mirror structure and the epitaxy through the through hole to ensure electrical transmission performance.

[0142] like Figure 1 As shown, the projection of the through hole of the epitaxial protection layer on the surface of the epitaxial structure is smaller than the projection of the through hole of the dielectric film reflective layer on the surface of the epitaxial structure, that is, the projection of the through hole of the epitaxial protection layer on the surface of the epitaxial structure is located within the projection of the through hole of the dielectric film reflective layer on the surface of the epitaxial structure. This through hole design facilitates the opening of through holes.

[0143] In the disclosed embodiment, there are multiple through holes, and the through holes of the epitaxial protection layer correspond to the through holes of the dielectric film reflective layer one by one. The aforementioned relationship refers to the relationship between the corresponding through holes in the two layers.

[0144] In addition, the epitaxial protection layer and the dielectric film reflective layer are provided with connecting through holes at the step surfaces of the step structures.

[0145] Exemplarily, step S26 may adopt buffered oxide etching (BOE) etching, inductively coupled plasma (ICP) etching, or a combination of ICP etching and BOE etching to form the above-mentioned through holes and connecting through holes.

[0146] S27. A silver mirror structure is manufactured on the dielectric film reflective layer, and the silver mirror structure is connected to the epitaxial structure through a through hole.

[0147] The silver mirror structure includes a reflective layer and a protective layer, which are sequentially stacked on the dielectric film reflective layer, the reflective layer is connected to the transparent conductive layer through a through hole, and the protective layer wraps the reflective layer.

[0148] In the embodiment of the present disclosure, the reflective layer is a silver mirror layer, and the reflective layer can be a combination of one or more metal or alloy layers such as Ag, Ni, Ti, TiW, Cr, Al, AlCu, Ti, Ni, Pt, and Au.

[0149] Exemplarily, the reflective layer is a stack of Ag, Ni, Ti and TiW, wherein the metal Ag is the main structure, which plays the role of light reflection and current expansion, and Ni, TiW, etc. play the role of preventing the migration and diffusion of metal silver.

[0150] In the embodiment of the present disclosure, the protective layer may be a combination of one or more metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt and Au.

[0151] Exemplarily, the protective layer is a stack of Cr, Al, AlCu, Ti, Ni, Pt and Au.

[0152] Exemplarily, the manufacturing process of the reflective layer includes:

[0153] A photoresist mask pattern is formed; under the shielding of the photoresist mask pattern, a silver reflective layer is formed on the surface of the dielectric layer by using magnetron sputtering technology, and the silver reflective layer is connected to the transparent conductive layer through a through hole.

[0154] Exemplarily, the process of making the protective layer includes:

[0155] A photoresist mask pattern is formed; and under the protection of the photoresist mask pattern, an electron beam vacuum evaporation technology is used to form a protective layer on the silver reflective layer.

[0156] S28. Make a first insulating layer, where the first insulating layer covers the silver mirror structure and the dielectric film reflective layer.

[0157] The first insulating layer has first insulating layer through holes respectively formed at the silver mirror structure and at the step surface of the step structure.

[0158] In the embodiment of the present disclosure, the first insulating layer may be a DBR layer or a SiO2 layer, and the DBR layer is a stacked layer formed by SiO2 and Ti3O5.

[0159] Exemplarily, when the first insulating layer is manufactured, an insulating layer film is first deposited, and then the first insulating layer through hole is formed by a patterning process.

[0160] When the first insulating layer is a SiO2 layer, the first insulating layer can be deposited by using PECVD equipment to form an insulating layer film.

[0161] When the first insulating layer is a DBR layer, the first insulating layer can be manufactured as an insulating layer film using an optical coating machine.

[0162] Exemplarily, in step S28, BOE etching or ICP etching method may be used to form the first insulating layer through hole.

[0163] S29, making a first electrode and a second electrode.

[0164] The first electrode is connected to the protective layer through the first insulating layer through hole at the silver mirror structure, and the second electrode is connected to the first semiconductor layer through the first insulating layer through hole and the connecting through hole at the step surface of the step structure.

[0165] In the embodiment of the present disclosure, the first electrode and the second electrode may be a combination of one or more metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt and Au.

[0166] Exemplarily, the first electrode and the second electrode are stacked layers of Cr, Al, AlCu, Ti, Ni, Pt and Au.

[0167] In one example, step S29 includes:

[0168] The first electrode and the second electrode are manufactured by electron beam evaporation technology.

[0169] S30, manufacturing a second insulating layer, wherein the second insulating layer covers the first electrode, the second electrode and the first insulating layer.

[0170] The second insulating layer has second insulating layer through holes respectively at the first electrode and the second electrode.

[0171] In the embodiment of the present disclosure, the second insulating layer may be a DBR layer or a SiO2 layer, and the DBR layer is a stacked layer formed by SiO2 and Ti3O5.

[0172] Illustratively, when the second insulating layer is manufactured, an insulating layer film is first deposited, and then a second insulating layer through hole is formed by a patterning process.

[0173] When the second insulating layer is a SiO2 layer, the second insulating layer can be deposited by using PECVD equipment to form an insulating layer film.

[0174] When the second insulating layer is a DBR layer, the second insulating layer can be manufactured as an insulating layer film using an optical coating machine.

[0175] Exemplarily, in step S30 , BOE etching or ICP etching method may be used to form the second insulating layer through hole.

[0176] S31 , manufacturing a first electrode pad and a second electrode pad.

[0177] The first electrode pad is connected to the first electrode through a through hole in the second insulating layer at the first electrode, and the second electrode pad is connected to the second electrode through a through hole in the second insulating layer at the second electrode.

[0178] In the embodiment of the present disclosure, the first electrode pad and the second electrode pad may be a combination of one or more metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt, Au and AuSn.

[0179] Exemplarily, the first electrode pad and the second electrode pad are stacked layers of Cr, Al, AlCu, Ti, Ni, Pt, Au, and AuSn.

[0180] In one example, step S31 includes:

[0181] The first electrode pad and the second electrode pad are manufactured by electron beam evaporation technology.

[0182] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A light emitting diode, characterized in that: The light emitting diode comprises: an epitaxial structure (10), a silver mirror structure (20), an epitaxial protective layer (60) and a dielectric film reflective layer (70); The epitaxial structure (10) is in the form of a step structure (115); the epitaxial protection layer (60) and the dielectric film reflection layer (70) are sequentially stacked on the step structure (115); the epitaxial protection layer (60) and the dielectric film reflection layer (70) are provided with corresponding through holes (670) on the surface of the epitaxial structure (10); the silver mirror structure (20) is located on the dielectric film reflection layer (70) and is connected to the epitaxial structure (10) via the through holes (670).

2. The light emitting diode according to claim 1, characterized in that: The epitaxial protective layer (60) is an epitaxial protective layer deposited by atomic layer deposition.

3. The light emitting diode according to claim 1, characterized in that: The epitaxial protection layer (60) is an Al2O3 thin film layer.

4. The light emitting diode according to claim 1, characterized in that: The thickness of the epitaxial protection layer (60) is 50 to 500 angstroms.

5. The light emitting diode according to any one of claims 1 to 4, characterized in that: The projection of the through hole (670) of the epitaxial protection layer (60) on the surface of the epitaxial structure (10) and the projection of the through hole (670) of the dielectric film reflection layer (70) on the surface of the epitaxial structure (10) are concentric circles.

6. A method for preparing a light emitting diode, characterized in that: The method comprises: fabricating epitaxial structures; Performing a patterning process on the epitaxial structure to form a step structure; An epitaxial protection layer and a dielectric film reflection layer are sequentially stacked on the surface of the step structure, wherein the epitaxial protection layer and the dielectric film reflection layer are provided with through holes correspondingly on the surface of the epitaxial structure; A silver mirror structure is manufactured on the dielectric film reflective layer, and the silver mirror structure is connected to the epitaxial structure through the through hole.

7. The method for preparing a light emitting diode according to claim 6, characterized in that: The method of manufacturing the epitaxial protective layer comprises: A first precursor H2O is introduced, wherein the first precursor H2O is adsorbed on the surface of the step structure; Use N2 flushing; A second precursor, trimethylaluminum, is introduced to react chemically with the first precursor to form an Al2O3 film with a thickness of one atomic layer; Flush with N2 again; Repeat the above steps for multiple cycles until the thickness of the Al2O3 film reaches the required value, thereby obtaining the epitaxial protective layer.

8. The method for preparing a light emitting diode according to claim 7, characterized in that: The temperature during preparation of the epitaxial protective layer is 200-260°C.

9. The method for preparing a light emitting diode according to claim 7, characterized in that: The thickness of the epitaxial protection layer is 50 to 500 angstroms.

10. The method for preparing a light emitting diode according to any one of claims 6 to 9, characterized in that: The projection of the through hole of the epitaxial protection layer on the surface of the epitaxial structure and the projection of the through hole of the dielectric film reflection layer on the surface of the epitaxial structure are concentric circles.

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