Light emitting diode and preparation method thereof

Abstract

The invention provides a light emitting diode and a preparation method thereof. The method comprises the following steps: manufacturing an epitaxial structure; performing patterning processing on the epitaxial structure to form a step structure; manufacturing a current blocking layer on the epitaxial structure, wherein the current blocking layer is provided with a first through hole and a second through hole; a metal reflection layer is manufactured on the surface of the current blocking layer, the metal reflection layer is provided with a through hole exposing the step structure, and the metal reflection layer is electrically connected with the epitaxial structure through the first through hole; manufacturing an insulation structure, wherein the insulation structure comprises a protective layer covering the metal reflecting layer; the protection layer is provided with a third through hole and a fourth through hole; the third through hole is formed in the metal reflecting layer, and the fourth through hole is located in the step surface of the step structure; manufacturing a first electrode structure and a second electrode structure, wherein the first electrode structure is electrically connected with the metal reflecting layer through the third through hole; the second electrode structure is electrically connected with the epitaxial structure through the fourth through hole and the second through hole.

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 same. 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 fields such as lighting and display.

[0003] The related art provides a light emitting diode, the structure of which includes an epitaxial structure, a metal structure, an insulating structure and an electrode structure.

[0004] The metal structure of the related art includes a metal reflective layer and a metal protective layer wrapping the metal reflective layer. The metal protective layer is used to prevent metal migration, but it causes the area of ​​the metal reflective layer to become smaller, thereby reducing the reflection area and affecting the light brightness. Summary of the invention

[0005] The embodiment of the present disclosure provides a light emitting diode and a method for manufacturing the same, which can increase the effective reflection area of ​​the metal reflection layer and improve the brightness of the light emitting diode. The technical solution is as follows:

[0006] In one aspect, a method for preparing a light emitting diode is provided, the method comprising:

[0007] Fabricating epitaxial structures;

[0008] Performing a patterning process on the epitaxial structure to form a step structure;

[0009] A current blocking layer is formed on the epitaxial structure, wherein the current blocking layer has a first through hole and a second through hole, wherein the first through hole is located on the surface of the epitaxial structure, and the second through hole is located on the step surface of the step structure;

[0010] A metal reflective layer is formed on the surface of the current blocking layer, wherein the metal reflective layer has a through hole exposing the step structure, and the metal reflective layer is electrically connected to the epitaxial structure through the first through hole;

[0011] An insulating structure is manufactured, wherein the insulating structure includes a protective layer covering the metal reflective layer; the protective layer covers the side wall of the step structure and a part of the step surface of the step structure; the protective layer has a third through hole and a fourth through hole; the third through hole is arranged on the metal reflective layer, and the first electrode structure is electrically connected to the metal reflective layer through the third through hole; the fourth through hole is located on the step surface of the step structure;

[0012] A first electrode structure and a second electrode structure are manufactured, wherein the first electrode structure is electrically connected to the metal reflective layer through the third through hole; and the second electrode structure is electrically connected to the epitaxial structure through the fourth through hole and the second through hole.

[0013] Optionally, a metal reflective layer is formed on the surface of the current blocking layer, comprising:

[0014] Applying a layer of photoresist on the surface of the current blocking layer;

[0015] Exposing and developing the photoresist to obtain a mask pattern, wherein the mask pattern corresponds to the area where the through hole is located;

[0016] Sputtering metal films;

[0017] The mask pattern and the metal film on the mask pattern are removed to obtain the metal reflective layer.

[0018] Optionally, the manufacturing of the insulating structure includes:

[0019] The protective layer is obtained by depositing Al2O3 using single atom deposition technology.

[0020] Optionally, the protective layer has a thickness of 300 to 1000 angstroms.

[0021] Optionally, a distance between a side wall of the through hole of the metal reflective layer and a side wall of the step structure is less than or equal to 11 micrometers.

[0022] In another aspect, a light emitting diode is provided, the light emitting diode comprising:

[0023] An epitaxial structure, a current blocking layer, a metal reflective layer, an insulating structure, a first electrode structure and a second electrode structure;

[0024] The epitaxial structure has a step structure; the current blocking layer and the metal reflective layer are sequentially stacked on the epitaxial structure; the metal reflective layer has a through hole exposing the step structure, and the current blocking layer has a first through hole and a second through hole, the first through hole is located on the surface of the epitaxial structure, and the second through hole is located on the step surface of the step structure; the metal reflective layer is electrically connected to the epitaxial structure through the first through hole, and the insulating structure includes a protective layer covering the metal reflective layer; the protective layer covers the side wall of the step structure and part of the step surface of the step structure; the protective layer has a third through hole and a fourth through hole; the third through hole is arranged on the metal reflective layer, and the first electrode structure is electrically connected to the metal reflective layer through the third through hole; the fourth through hole is located on the step surface of the step structure, and the second electrode structure is electrically connected to the epitaxial structure through the fourth through hole and the second through hole.

[0025] Optionally, the protective layer is an Al2O3 layer.

[0026] Optionally, the protective layer has a thickness of 300 to 1000 angstroms.

[0027] Optionally, a distance between a side wall of the through hole of the metal reflective layer and a side wall of the step structure is less than or equal to 14 micrometers.

[0028] Optionally, a distance between a side wall of the through hole of the metal reflective layer and a side wall of the step structure is less than or equal to 11 micrometers.

[0029] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:

[0030] In the related art, the metal migration is prevented by wrapping the metal reflective layer with a protective layer, which will sacrifice a certain line width and area of ​​the metal reflective layer. In the embodiment of the present disclosure, the protective layer covers a part of the metal reflective layer, and the protective layer covers the side wall and part of the step surface of the step structure exposed by the through hole of the metal reflective layer, that is, the protective layer adopts a structure extending from the side wall of the step structure extending from the metal reflective layer to part of the step surface, rather than wrapping the entire metal reflective layer, so that the through hole opened by the metal reflective layer can be reduced, and the distance between the side wall of the through hole of the metal reflective layer and the side wall of the step structure can be reduced, thereby increasing the line width of the metal reflective layer on the surface of the epitaxial structure and the area of ​​the metal reflective layer, and improving the brightness of the light-emitting diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] 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.

[0032] Figure 1 is a flow chart of a method for preparing a light emitting diode provided by an embodiment of the present disclosure;

[0033] Figure 2 is a flow chart of another method for preparing a light emitting diode provided by an embodiment of the present disclosure;

[0034] Figure 3 It is a structural schematic diagram of a light emitting diode provided in an embodiment of the present disclosure.

[0035] The reference numerals are as follows:

[0036] 10: epitaxial structure; 30: insulating structure; 100: substrate; 101: first semiconductor layer; 102: active layer; 103: second semiconductor layer; 104: transparent conductive layer; 105: current blocking layer; 106: metal reflective layer; 107: protective layer; 110: first electrode; 112: first electrode pad; 111: second electrode; 113: second electrode pad; 108: first insulating layer; 109: second insulating layer; 201: step structure; 202: isolation groove; 301: first insulating layer through hole; 302: second insulating layer through hole; 401: first electrode structure; 402: second electrode structure; 601: first through hole; 602: second through hole; 171: third through hole; 172: fourth through hole; 2000: through hole. DETAILED DESCRIPTION

[0037] 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.

[0038] Figure 1 is a flow chart of a method for preparing a light emitting diode provided by an embodiment of the present disclosure. Figure 1 The method steps include:

[0039] S11. Fabricating an epitaxial structure.

[0040] S12, performing graphic processing on the epitaxial structure to form a step structure.

[0041] S13, manufacturing a current blocking layer on the epitaxial structure, wherein the current blocking layer has a first through hole and a second through hole, wherein the first through hole is located on the surface of the epitaxial structure, and the second through hole is located on the step surface of the step structure.

[0042] S14, manufacturing a metal reflective layer on the surface of the current blocking layer, wherein the metal reflective layer has a through hole exposing the step structure, and the metal reflective layer is electrically connected to the epitaxial structure through the first through hole.

[0043] S15. Make an insulating structure, the insulating structure includes a protective layer covering the metal reflective layer; the protective layer covers the side wall of the step structure and part of the step surface of the step structure; the protective layer has a third through hole and a fourth through hole; the third through hole is arranged on the metal reflective layer, and the fourth through hole is located on the step surface of the step structure.

[0044] S16, manufacturing a first electrode structure and a second electrode structure, wherein the first electrode structure is electrically connected to the metal reflective layer through the third through hole; and the second electrode structure is electrically connected to the epitaxial structure through the fourth through hole and the second through hole.

[0045] In the related art, the metal migration is prevented by wrapping the metal reflective layer with a protective layer, which will sacrifice a certain line width and area of ​​the metal reflective layer. In the embodiment of the present disclosure, the protective layer covers a part of the metal reflective layer, and the protective layer covers the side wall and part of the step surface of the step structure exposed by the through hole of the metal reflective layer, that is, the protective layer adopts a structure extending from the side wall of the step structure extending from the metal reflective layer to part of the step surface, rather than wrapping the entire metal reflective layer, so that the through hole opened by the metal reflective layer can be reduced, and the distance between the side wall of the through hole of the metal reflective layer and the side wall of the step structure can be reduced, thereby increasing the line width of the metal reflective layer on the surface of the epitaxial structure and the area of ​​the metal reflective layer, and improving the brightness of the light-emitting diode.

[0046] Figure 2 is a flow chart of another method for preparing a light emitting diode provided by an embodiment of the present disclosure. Figure 2 The method steps include:

[0047] 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.

[0048] The substrate may be any one of a sapphire substrate, a Si substrate, a SiC substrate and the like.

[0049] Exemplarily, the substrate is a sapphire substrate.

[0050] In one example, step S21 includes:

[0051] The first step is to make the first semiconductor layer.

[0052] In the embodiment of the present disclosure, the first semiconductor layer may be an N-type GaN layer.

[0053] The second step is to make the active layer.

[0054] In the embodiment of the present disclosure, the active layer may be a multi-quantum well layer, such as an InGaN / GaN multi-quantum well structure.

[0055] The third step is to make the second semiconductor layer.

[0056] In the embodiment of the present disclosure, the second semiconductor layer may be a P-type GaN layer.

[0057] In the disclosed embodiment, VeecoK465i or C4 or RB MOCVD (Metal Organic Chemical Vapor Deposition, metal organic compound chemical vapor deposition (MOCVD)) equipment or AIXTRON metal organic compound chemical vapor deposition equipment can be used to achieve the growth of the above semiconductor layer. High-purity H2 (hydrogen) or high-purity N2 (nitrogen) or a mixed gas 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, trimethylaluminum (TMAl) is used as an aluminum source, and bis(cyclopentadienyl) magnesium (CP2Mg) is used as a P-type dopant.

[0058] S22, performing graphic processing on the epitaxial structure to form a step structure and an isolation groove, wherein the step surface of the step structure and the isolation groove are located in the epitaxial structure.

[0059] In the disclosed embodiment, the first semiconductor layer, the active layer and the second semiconductor layer are in a step structure, and 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, and the bottom of the isolation groove is located in the first semiconductor layer.

[0060] Exemplarily, step S22 may include:

[0061] A patterned mask layer is formed on the surface of the second semiconductor layer; under the protection of the mask layer, the epitaxial structure is etched to form a step structure and an isolation groove extending to the substrate.

[0062] S23. Fabricating a transparent conductive layer on the epitaxial structure.

[0063] In the embodiment of the present disclosure, the transparent conductive layer may be an indium tin oxide (ITO) layer. ITO has good transparency and conductivity, allowing light to pass through while also conducting current well.

[0064] S24, manufacturing a current blocking layer on the transparent conductive layer, wherein the current blocking layer has a first through hole and a second through hole, wherein the first through hole is located on the surface of the epitaxial structure, and the second through hole is located on the step surface of the step structure.

[0065] In the embodiment of the present disclosure, the current blocking layer may be a SiO2 layer.

[0066] In one example, step S24 includes:

[0067] The first step is to make a current blocking film on the transparent conductive layer.

[0068] In the second step, a layer of photoresist is coated on the surface of the current blocking film.

[0069] The third step is to expose and process the photoresist to obtain a mask pattern.

[0070] The fourth step is to etch the current blocking film under the protection of the mask pattern to obtain a current blocking layer.

[0071] The current blocking film may be etched by etching.

[0072] S25, manufacturing a metal reflective layer on the current blocking layer, wherein the metal reflective layer has a through hole exposing the step structure, and the metal reflective layer is electrically connected to the epitaxial structure through the first through hole.

[0073] In the embodiment of the present disclosure, the metal reflective layer may be a silver mirror reflective layer.

[0074] In one example, step S25 includes:

[0075] The first step is to apply a layer of photoresist on the surface of the current blocking layer.

[0076] Illustratively, the photoresist may be a negative photoresist.

[0077] In the disclosed embodiment, the thickness of the negative photoresist is 2.5-3.5 μm.

[0078] Exemplarily, the thickness of the negative photoresist is 3 μm. Negative photoresist with this thickness can improve lithography resolution, reduce standing wave effect, reduce line edge roughness, improve production efficiency and product quality, while reducing material cost and process complexity.

[0079] In the second step, the photoresist is exposed and developed to obtain a mask pattern, wherein the mask pattern corresponds to the area where the through hole is located.

[0080] The exposure process is as follows: the photoresist is irradiated with ultraviolet light under the mask.

[0081] In the embodiment of the present disclosure, the exposure energy of the ultraviolet light may be 200-230 mj.

[0082] Exemplarily, the exposure energy of the ultraviolet light is 210 mj, which helps to achieve high resolution, high contrast and low defect rate in the lithography process.

[0083] The developing process is as follows: washing is performed using a developing solution.

[0084] Optionally, after the second step, the method further comprises: placing the dried fruits in a hot plate for baking, and then flushing them in a flushing machine.

[0085] In the embodiment of the present disclosure, the baking temperature may be 120-130° C., and the baking time may be 5-8 minutes.

[0086] Exemplarily, the baking temperature is 125° C. and the baking time is 6 minutes, which can enhance the adhesion of the photoresist and control the tilt angle of the photoresist.

[0087] The flushing is performed on the flushing machine for 15-20 minutes, for example 18 minutes.

[0088] The third step is sputtering metal film.

[0089] The sputtering distance of the metal film is generally 1 to 3 μm, for example, 2 μm.

[0090] The fifth step is to remove the mask pattern and the metal film on the mask pattern to obtain the metal reflective layer.

[0091] The portion blocked by the mask pattern is the portion where metal sputtering is not required, that is, the area corresponding to the through hole.

[0092] In the disclosed embodiment, the epitaxial wafer after the sputtering operation is subjected to two blue film stripping and de-resining operations.

[0093] In the disclosed embodiment, ethanol is used to clean the epitaxial wafer.

[0094] In the embodiment of the present disclosure, the distance between the sidewall of the through hole of the metal reflective layer and the sidewall of the step structure is less than or equal to 14 micrometers.

[0095] In the embodiment of the present disclosure, the distance between the sidewall of the through hole of the metal reflective layer and the sidewall of the step structure is less than or equal to 11 micrometers.

[0096] Exemplarily, the distance between the sidewall of the through hole of the metal reflective layer and the sidewall of the step structure is 8 micrometers.

[0097] In the embodiment of the present disclosure, by designing the protective layer structure, the distance between the side wall of the through hole of the metal reflective layer and the side wall of the step structure is reduced to 8 microns compared to 14 microns in the related art, thereby greatly increasing the area of ​​the metal reflective layer.

[0098] S26, making a protective layer on the metal reflective layer; the protective layer covers the side wall of the step structure and part of the step surface of the step structure; the protective layer has a third through hole and a fourth through hole; the third through hole is arranged on the metal reflective layer, and the fourth through hole is located on the step surface of the step structure.

[0099] In the disclosed embodiment, the protective layer may be an Al2O3 layer deposited by atomic layer deposition (ALD). For example, Al2O3 is deposited by single atom deposition technology to obtain the protective layer. The protective layer is deposited by single atom deposition technology to prevent silver migration. The protective layer occupies a small area and can maximize the effective reflection area of ​​the metal reflection layer.

[0100] In the disclosed embodiment, the thickness of the protective layer may be 300 to 1000 angstroms, which can not only prevent silver migration, but also reduce the area occupied by the protective layer, thereby maximizing the effective reflection area of ​​the metal.

[0101] Exemplarily, Al2O3 layer deposition is performed in a single atomic layer deposition machine.

[0102] Illustratively, the protective layer is 500 angstroms.

[0103] S27, making a first insulating layer.

[0104] Wherein, the first insulating layer covers the protective layer, the transparent conductive layer and the metal reflective layer.

[0105] Exemplarily, step S27 may include:

[0106] In the first step, a SiO2 layer is formed by a vapor deposition process to obtain a first insulating layer.

[0107] The second step is to perform patterning on the first insulating layer and to open through holes in the first insulating layer.

[0108] The first insulating layer has first insulating layer through holes respectively formed at the metal reflective layer and the step structure, which are respectively connected to the third through hole and the fourth through hole of the protective layer.

[0109] S28, manufacturing a first electrode and a second electrode.

[0110] 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.

[0111] Exemplarily, the first electrode and the second electrode are stacked layers of Cr, Al, AlCu, Ti, Ni, Pt and Au.

[0112] The first electrode is connected to the metal reflective layer through the first insulating layer through hole and the third through hole at the metal reflective layer, and the second electrode is connected to the first semiconductor layer through the first insulating layer through hole and the fourth through hole at the step structure.

[0113] S29, making a second insulating layer.

[0114] The second insulating layer covers the first electrode, the second electrode and the first insulating layer.

[0115] Exemplarily, step S29 may include:

[0116] In the first step, a SiO2 layer is produced by an evaporation process to obtain a second insulating layer.

[0117] The second step is to perform patterning on the second insulating layer and to open through holes in the second insulating layer.

[0118] The second insulating layer has first insulating layer through holes respectively at the first electrode and the second electrode.

[0119] The first insulating layer, the second insulating layer and the protective layer constitute the aforementioned insulating structure.

[0120] In other examples, both the first insulating layer and the second insulating layer may be distributed Bragg reflector (DBR) layers.

[0121] The DBR layer may be a stacked layer formed by at least one period of a silicon oxide layer (eg SiO2) and a titanium oxide layer (eg Ti3O5, Ti2O3).

[0122] S30, manufacturing a first electrode pad and a second electrode pad.

[0123] 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.

[0124] 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 manufactured by an evaporation process.

[0125] Exemplarily, the first electrode pad and the second electrode pad are stacked layers of Cr, Al, AlCu, Ti, Ni, Pt, Au, and AuSn.

[0126] The first electrode, the second electrode, the first electrode pad and the second electrode pad constitute the aforementioned electrode structure.

[0127] Compared with the LED structure provided by the related art, the area of ​​the metal reflective layer in the embodiment of the present disclosure is increased by 4.8%, and the product brightness is improved by 3%.

[0128] Figure 3 is a schematic diagram of the structure of a light emitting diode provided by an embodiment of the present disclosure. Figure 3The light emitting diode comprises: an epitaxial structure 10 , a current blocking layer 105 , a metal reflective layer 106 , an insulating structure 30 , a first electrode structure 401 and a second electrode structure 402 .

[0129] The epitaxial structure 10 has a step structure 201; the current blocking layer 105 and the metal reflective layer 106 are sequentially stacked on the epitaxial structure 10; the metal reflective layer 106 has a through hole 2000 exposing the step structure 201, and the current blocking layer 105 has a first through hole 601 and a second through hole 602, the first through hole 601 is located on the surface of the epitaxial structure 10, and the second through hole 602 is located on the step surface of the step structure 201; the metal reflective layer 106 is electrically connected to the epitaxial structure 10 through the first through hole 601, and the insulating structure 30 includes a through hole 2000 covering the metal reflective layer 106. A protective layer 107 is provided on the metal reflective layer; the protective layer 107 covers the side wall of the step structure 201 and a part of the step surface of the step structure 201, and the protective layer 107 has a third through hole 171 and a fourth through hole 172; the third through hole 171 is provided on the metal reflective layer 106, and the first electrode structure 401 is electrically connected to the metal reflective layer 106 through the third through hole 171; the fourth through hole 172 is located on the step surface of the step structure 201, and the second electrode structure 402 is electrically connected to the epitaxial structure 10 through the fourth through hole 172 and the second through hole 602.

[0130] In the related art, the metal migration is prevented by wrapping the metal reflective layer with a protective layer, which will sacrifice a certain line width and area of ​​the metal reflective layer. In the embodiment of the present disclosure, the protective layer covers a part of the metal reflective layer, and the protective layer covers the side wall and part of the step surface of the step structure exposed by the through hole of the metal reflective layer, that is, the protective layer adopts a structure extending from the side wall of the step structure extending from the metal reflective layer to part of the step surface, rather than wrapping the entire metal reflective layer, so that the through hole opened by the metal reflective layer can be reduced, and the distance between the side wall of the through hole of the metal reflective layer and the side wall of the step structure can be reduced, thereby increasing the line width of the metal reflective layer on the surface of the epitaxial structure and the area of ​​the metal reflective layer, and improving the brightness of the light-emitting diode.

[0131] In the embodiment of the present disclosure, the distance between the sidewall A of the through hole of the metal reflective layer 106 and the sidewall B of the step structure 201 is less than or equal to 14 micrometers.

[0132] In the embodiment of the present disclosure, the distance between the side wall A of the through hole of the metal reflective layer 106 and the side wall B of the step structure 201 is less than or equal to 11 micrometers.

[0133] Exemplarily, the distance between the sidewall A of the through hole of the metal reflective layer 106 and the sidewall B of the step structure 201 is 8 micrometers.

[0134] In the embodiment of the present disclosure, by designing the protective layer structure, the distance between the side wall of the through hole of the metal reflective layer 106 and the side wall of the step structure 201 is reduced to 8 microns compared to 14 microns in the related art, thereby greatly increasing the area of ​​the metal reflective layer.

[0135] In the embodiment of the present disclosure, the through hole 2000 may be circular, and the radius of the through hole 2000 may be 25 to 32 microns (smaller than 33 microns in the related art), for example, 27 microns.

[0136] In the embodiment of the present disclosure, the step surface of the step structure may be circular, and the radius may be 15 to 20 microns, for example, 19 microns.

[0137] Optionally, the light emitting diode further includes a substrate 100 , and the epitaxial structure 10 is located on the substrate 100 .

[0138] Optionally, the epitaxial structure 10 is further provided with an isolation trench (ISO) 202 , and the insulating structure 30 also covers the isolation trench 202 .

[0139] 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 .

[0140] The first semiconductor layer 101, the active layer 102, and the second semiconductor layer 103 are sequentially stacked on the substrate 100. The first semiconductor layer 101, the active layer 102, and the second semiconductor layer 103 are provided with a step structure 201 extending to the first semiconductor 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 groove 202 extending to the first semiconductor layer 101. In other examples, the isolation groove can also be opened to the surface of the substrate 100.

[0141] 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.

[0142] Exemplarily, the substrate 100 is a sapphire substrate.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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 structure.

[0147] Optionally, the light emitting diode may further include a transparent conductive layer 104 , and the transparent conductive layer 104 is located on the epitaxial structure 10 , for example, on the second semiconductor layer 103 .

[0148] In the embodiment of the present disclosure, the transparent conductive layer 104 may be an ITO layer. ITO has good transparency and conductivity, allowing light to pass through while also conducting current well.

[0149] In the embodiment of the present disclosure, the current blocking layer 105 may be a SiO 2 layer.

[0150] In the embodiment of the present disclosure, the metal reflective layer 106 may be a silver mirror reflective layer.

[0151] In the embodiment of the present disclosure, the protective layer 107 may be an Al2O3 layer deposited by ALD, and the thickness may be 300 to 1000 angstroms.

[0152] Exemplarily, the protective layer 107 is 500 angstroms.

[0153] Optionally, the insulating structure 30 further includes a first insulating layer 108 , and the first insulating layer 108 covers the protection layer 107 , the transparent conductive layer 104 and the metal reflective layer 106 .

[0154] Optionally, the insulating structure further includes a second insulating layer 109 , and the second insulating layer 109 covers the second electrode 110 and the first insulating layer 108 .

[0155] Exemplarily, both the first insulating layer 108 and the second insulating layer 109 may be SiO 2 layers.

[0156] Exemplarily, both the first insulating layer 108 and the second insulating layer 109 may be DBR layers.

[0157] The DBR layer may be a stacked layer formed by at least one period of a silicon oxide layer (eg SiO2) and a titanium oxide layer (eg Ti3O5, Ti2O3).

[0158] Exemplarily, the first electrode structure 401 includes a first electrode 110 and a first electrode pad 112 , and the second electrode structure 402 includes a second electrode 111 and a second electrode structure 113 .

[0159] The first insulating layer 108 has first insulating layer through holes 301 at the metal reflective layer 106 and at the step structure 201, respectively. The first electrode 110 is connected to the metal reflective layer 106 through the first insulating layer through hole 301 and the third through hole at the metal reflective layer 106, and the second electrode 111 is connected to the first semiconductor layer 101 through the first insulating layer through hole 301 and the fourth through hole at the step structure 201. The second insulating layer 109 has first insulating layer through holes 301 at the first electrode 110 and the second electrode 111, respectively. The first electrode pad 112 is connected to the first electrode 110 through the second insulating layer through hole 302 at the first electrode 110, and the second electrode pad 113 is connected to the second electrode 111 through the second insulating layer through hole 302 at the second electrode 111.

[0160] Exemplarily, the first electrode 110 and the second electrode 111 are stacked layers of Cr, Al, AlCu, Ti, Ni, Pt, and Au.

[0161] In the embodiment of the present disclosure, the first electrode pad 112 and the second electrode pad 113 may be a combination of one or more metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt, Au and AuSn made by an evaporation process.

[0162] Exemplarily, the first electrode pad 112 and the second electrode pad 113 are stacked layers of Cr, Al, AlCu, Ti, Ni, Pt, Au, and AuSn.

[0163] 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.

[0164] 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 method for preparing a light emitting diode, characterized in that: The method comprises: fabricating an epitaxial structure (10); Performing a patterning process on the epitaxial structure (10) to form a step structure (201); A current blocking layer (105) is fabricated on the epitaxial structure (10), wherein the current blocking layer (105) has a first through hole (601) and a second through hole (602), wherein the first through hole (601) is located on the surface of the epitaxial structure (10), and the second through hole (602) is located on the step surface of the step structure (201); A metal reflective layer (106) is fabricated on the surface of the current blocking layer (105), wherein the metal reflective layer (106) has a through hole (2000) exposing the step structure (201), and the metal reflective layer (106) is electrically connected to the epitaxial structure (10) through the first through hole (601); An insulating structure (30) is manufactured, wherein the insulating structure (30) comprises a protective layer (107) covering the metal reflective layer (106); the protective layer (107) covers the side wall of the step structure (201) and a portion of the step surface of the step structure (201); the protective layer (107) has a third through hole (171) and a fourth through hole (172); the third through hole (171) is arranged on the metal reflective layer (106), and the fourth through hole (172) is located on the step surface of the step structure (201); A first electrode structure (401) and a second electrode structure (402) are manufactured, wherein the first electrode structure (401) is electrically connected to the metal reflective layer (106) through the third through hole (171); and the second electrode structure (402) is electrically connected to the epitaxial structure (10) through the fourth through hole (172) and the second through hole (602).

2. The method for preparing a light emitting diode according to claim 1, characterized in that: Producing a metal reflective layer (106) on the surface of the current blocking layer (105), comprising: Applying a layer of photoresist on the surface of the current blocking layer (105); exposing and developing the photoresist to obtain a mask pattern, wherein the mask pattern corresponds to the area where the through hole (2000) is located; Sputtering metal films; The mask pattern and the metal film on the mask pattern are removed to obtain the metal reflective layer (106).

3. The method for preparing a light emitting diode according to claim 1 or 2, characterized in that: The manufacturing of the insulating structure (30) comprises: Al2O3 is deposited by single atom deposition technology to obtain the protective layer (107).

4. The method for preparing a light emitting diode according to claim 3, characterized in that: The thickness of the protective layer (107) is 300 to 1000 angstroms.

5. The method for preparing a light emitting diode according to claim 1 or 2, characterized in that: The distance between the side wall of the through hole of the metal reflective layer (106) and the side wall of the step structure (201) is less than or equal to 11 micrometers.

6. A light emitting diode, characterized in that: The light-emitting diode comprises: an epitaxial structure (10), a current blocking layer (105), a metal reflective layer (106), an insulating structure (30), a first electrode structure (401) and a second electrode structure (402); The epitaxial structure (10) has a step structure (201); the current blocking layer (105) and the metal reflective layer (106) are sequentially stacked on the epitaxial structure (10); the metal reflective layer (106) has a through hole (2000) exposing the step structure (201); the current blocking layer (105) has a first through hole (601) and a second through hole (602); the first through hole (601) is located on the surface of the epitaxial structure (10), and the second through hole (602) is located on the step surface of the step structure (201); the metal reflective layer (106) is electrically connected to the epitaxial structure (10) through the first through hole (601); the insulating structure (30) includes a through hole (2000) covering the metal reflective layer; The invention relates to a protective layer (107) on the metal reflective layer (106); the protective layer (107) covers the side wall of the step structure (201) and part of the step surface of the step structure (201); the protective layer (107) has a third through hole (171) and a fourth through hole (172); the third through hole (171) is arranged on the metal reflective layer (106), and the first electrode structure (401) is electrically connected to the metal reflective layer (106) through the third through hole (171); the fourth through hole (172) is located on the step surface of the step structure (201), and the second electrode structure (402) is electrically connected to the epitaxial structure (10) through the fourth through hole (172) and the second through hole (602).

7. The light emitting diode according to claim 6, characterized in that: The protective layer (107) is an Al2O3 layer.

8. The light emitting diode according to claim 7, characterized in that: The thickness of the protective layer (107) is 300 to 1000 angstroms.

9. The light emitting diode according to any one of claims 6 to 8, characterized in that: The distance between the side wall of the through hole of the metal reflective layer (106) and the side wall of the step structure (201) is less than or equal to 14 micrometers.

10. The light emitting diode according to claim 9, characterized in that: The distance between the side wall of the through hole of the metal reflective layer (106) and the side wall of the step structure (201) is less than or equal to 11 micrometers.

Images