Light emitting diode and method of manufacturing the same

Abstract

The present disclosure provides a light emitting diode and a preparation method thereof. The method comprises: preparing an epitaxial structure; performing a patterning process on the epitaxial structure to form a step structure; preparing a current blocking layer on the epitaxial structure, the current blocking layer having a first through hole and a second through hole; preparing a metal reflective layer on the surface of the current blocking layer, the metal reflective layer having a through hole exposing the step structure, the metal reflective layer being electrically connected to the epitaxial structure through the first through hole; preparing an insulating structure, the insulating structure comprising a protective layer covering the metal reflective layer; the protective layer having a third through hole and a fourth through hole; the third through hole being arranged on the metal reflective layer, and the fourth through hole being located on a step surface of the step structure; preparing a first electrode structure and a second electrode structure, the first electrode structure being electrically connected to the metal reflective layer through the third through hole; and the second electrode structure being electrically connected to the epitaxial structure through the fourth through hole, the second through hole and the epitaxial structure.

Description

Technical Field

[0001] This disclosure relates to the field of light-emitting devices, and in particular to a light-emitting diode and a method for fabricating the same. Background Technology

[0002] Light-emitting diodes (LEDs) are semiconductor devices that emit light. They have advantages such as energy saving, high brightness, high durability, long life and light weight, and have been widely used in lighting and display fields.

[0003] The related technology 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 technology includes a metal reflective layer and a metal protective layer that wraps around the metal reflective layer. The metal protective layer is used to prevent metal migration, but it reduces the area of ​​the metal reflective layer, thereby reducing the reflective area and affecting the brightness of the emitted light. Summary of the Invention

[0005] This disclosure provides a light-emitting diode and its fabrication method, which can increase the effective reflective area of ​​the metal reflective layer and improve the brightness of the light-emitting diode. The technical solution is as follows:

[0006] On one hand, a method for fabricating a light-emitting diode is provided, the method comprising:

[0007] Fabrication of epitaxial structures;

[0008] The extensional structure is graphically processed to form a stepped structure;

[0009] A current blocking layer is fabricated on the epitaxial structure. 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 stepped structure.

[0010] A metal reflective layer is formed on the surface of the current blocking layer. The metal reflective layer has a through-hole that exposes the stepped structure. The metal reflective layer is electrically connected to the epitaxial structure through the first through-hole.

[0011] An insulating structure is fabricated, the insulating structure including a protective layer covering the metal reflective layer; the protective layer covers the sidewalls of the stepped structure and a portion of the stepped surface of the stepped structure; the protective layer has a third through hole and a fourth through hole; the third through hole is disposed 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 stepped surface of the stepped structure;

[0012] A first electrode structure and a second electrode structure are fabricated. The first electrode structure is electrically connected to the metal reflective layer through the third through-hole. The second electrode structure is electrically connected to the epitaxial structure through the fourth through-hole and the second through-hole.

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

[0014] A layer of photoresist is coated on the surface of the current blocking layer;

[0015] The photoresist is exposed and developed to obtain a mask pattern, which corresponds to the area where the via is located;

[0016] Sputtering metal thin films;

[0017] Remove the mask pattern and the metal film on the mask pattern to obtain the metal reflective layer.

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

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

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

[0021] Optionally, the distance between the sidewall of the through-hole in the metal reflective layer and the sidewall of the stepped structure is less than or equal to 11 micrometers.

[0022] On the other hand, a light-emitting diode is provided, the light-emitting diode comprising:

[0023] Epitaxial structure, current blocking layer, metal reflective layer, insulating structure, first electrode structure and second electrode structure;

[0024] The epitaxial structure has a stepped 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 stepped structure, the current blocking layer has a first through-hole and a second through-hole, the first through-hole being located on the surface of the epitaxial structure, and the second through-hole being located on the step surface of the stepped 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 sidewalls of the stepped structure and part of the step surface of the stepped structure; the protective layer has a third through-hole and a fourth through-hole; the third through-hole is disposed 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 stepped 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 thickness of the protective layer is 300 to 1000 angstroms.

[0027] Optionally, the distance between the sidewall of the through-hole in the metal reflective layer and the sidewall of the stepped structure is less than or equal to 14 micrometers.

[0028] Optionally, the distance between the sidewall of the through-hole in the metal reflective layer and the sidewall of the stepped structure is less than or equal to 11 micrometers.

[0029] The beneficial effects of the technical solutions provided in this disclosure are:

[0030] In related technologies, preventing metal migration by wrapping a metal reflective layer with a protective layer sacrifices some linewidth and the area of ​​the metal reflective layer. In this embodiment, the protective layer covers a portion of the metal reflective layer, and specifically covers the sidewalls and part of the stepped surface of the stepped structure exposed by the through-holes in the metal reflective layer. That is, the protective layer extends from the metal reflective layer to the sidewalls of the stepped structure and then to part of the stepped surface, rather than wrapping the entire metal reflective layer. This reduces the number of through-holes in the metal reflective layer, decreases the distance between the sidewalls of the through-holes and the sidewalls of the stepped structure, increases the linewidth and area of ​​the metal reflective layer on the surface of the epitaxial structure, and improves the brightness of the light-emitting diode. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a flowchart of a method for fabricating a light-emitting diode provided in an embodiment of this disclosure;

[0033] Figure 2 This is a flowchart of another method for fabricating a light-emitting diode provided in this disclosure embodiment;

[0034] Figure 3 This is a schematic diagram of the structure of a light-emitting diode provided in an embodiment of this disclosure.

[0035] The attached figures are labeled 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: Stepped structure; 202: Isolation trench; 301: Through-hole in the first insulating layer; 302: Through-hole in the second insulating layer; 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 Implementation

[0037] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0038] Figure 1 This is a flowchart illustrating a method for fabricating a light-emitting diode (LED) according to an embodiment of this disclosure. See also... Figure 1 The method includes the following steps:

[0039] S11. Fabricate the extensional structure.

[0040] S12. The extensional structure is graphically processed to form a stepped structure.

[0041] S13. A current blocking layer is fabricated on the epitaxial structure. 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.

[0042] S14. A metal reflective layer is fabricated on the surface of the current blocking layer. The metal reflective layer has a through-hole that exposes the stepped structure. The metal reflective layer is electrically connected to the epitaxial structure through the first through-hole.

[0043] S15. Fabricate an insulating structure, the insulating structure including a protective layer covering the metal reflective layer; the protective layer covers the sidewalls of the stepped structure and part of the stepped surface of the stepped structure; the protective layer has a third through hole and a fourth through hole; the third through hole is disposed on the metal reflective layer, and the fourth through hole is located on the stepped surface of the stepped structure.

[0044] S16. Fabricate a first electrode structure and a second electrode structure. The first electrode structure is electrically connected to the metal reflective layer through a third through-hole. The second electrode structure is electrically connected to the epitaxial structure through a fourth through-hole and a second through-hole.

[0045] In related technologies, preventing metal migration by wrapping a metal reflective layer with a protective layer sacrifices some linewidth and the area of ​​the metal reflective layer. In this embodiment, the protective layer covers a portion of the metal reflective layer, and specifically covers the sidewalls and part of the stepped surface of the stepped structure exposed by the through-holes in the metal reflective layer. That is, the protective layer extends from the metal reflective layer to the sidewalls of the stepped structure and then to part of the stepped surface, rather than wrapping the entire metal reflective layer. This reduces the number of through-holes in the metal reflective layer, decreases the distance between the sidewalls of the through-holes and the sidewalls of the stepped structure, increases the linewidth and area of ​​the metal reflective layer on the surface of the epitaxial structure, and improves the brightness of the light-emitting diode.

[0046] Figure 2 This is a flowchart of another method for fabricating a light-emitting diode provided in this disclosure. See also... Figure 2 The method includes the following steps:

[0047] S21. A first semiconductor layer, an active layer, and a second semiconductor layer are sequentially formed on a substrate, and the second semiconductor layer, the active layer, and the first semiconductor layer constitute an epitaxial structure.

[0048] The substrate can be any one of sapphire substrate, Si substrate, and SiC substrate.

[0049] For example, the substrate is a sapphire substrate.

[0050] In one example, step S21 includes:

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

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

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

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

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

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

[0057] In the embodiments disclosed herein, the above-mentioned semiconductor layer can be grown using a Veeco K465i, C4, or RB MOCVD (Metal Organic Chemical Vapor Deposition) apparatus or an AIXTRON MOCVD apparatus. High-purity H2 (hydrogen), high-purity N2 (nitrogen), or a mixture of high-purity H2 and high-purity N2 is used as the carrier gas; high-purity NH3 is used as the N source; trimethylgallium (TMGa) and triethylgallium (TEGa) are used as gallium sources; trimethylindium (TMIn) is used as the indium source; silane (SiH4) is used as the N-type dopant; trimethylaluminum (TMAl) is used as the aluminum source; and magnesium pyrocene (CP2Mg) is used as the P-type dopant.

[0058] S22. The extensional structure is graphically processed to form a stepped structure and an isolation groove. The stepped surface of the stepped structure and the isolation groove are located within the extensional structure.

[0059] In this embodiment, the first semiconductor layer, the active layer, and the second semiconductor layer have a stepped structure, with the stepped surface located on the first semiconductor layer. The first semiconductor layer, the active layer, and the second semiconductor layer also have isolation trenches, with the bottom of the isolation trenches located on the first semiconductor layer.

[0060] For example, step S22 may include:

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

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

[0063] In this embodiment, the transparent conductive layer can be an indium tin oxide (ITO) layer. ITO has excellent transparency and conductivity, allowing light to pass through while also enabling good current conduction.

[0064] S24. A current blocking layer is fabricated on the transparent conductive layer. 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.

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

[0066] In one example, step S24 includes:

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

[0068] The second step is to coat the surface of the current blocking film with a layer of photoresist.

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

[0070] The fourth step involves etching the current blocking film under the mask pattern to obtain the current blocking layer.

[0071] One method is to etch the current-blocking film using an etching process.

[0072] S25. A metal reflective layer is fabricated on the current blocking layer. The metal reflective layer has a through-hole that exposes a stepped structure. The metal reflective layer is electrically connected to the epitaxial structure through a first through-hole.

[0073] In this embodiment of the 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 coat the surface of the current blocking layer with a layer of photoresist.

[0076] For example, the photoresist can be a negative photoresist.

[0077] In this embodiment of the disclosure, the thickness of the negative photoresist is 2.5 to 3.5 μm.

[0078] For example, the thickness of the negative photoresist is 3 μm. This thickness of negative photoresist can improve photolithography resolution, reduce standing wave effect, reduce line edge roughness, improve production efficiency and product quality, while reducing material costs and process complexity.

[0079] The second step is to expose and develop the photoresist to obtain a mask pattern, which corresponds to the area where the via is located.

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

[0081] In this embodiment of the disclosure, the exposure energy of ultraviolet light can be 200-230 mJ.

[0082] For example, the exposure energy of ultraviolet light is 210 mJ, which helps to achieve high resolution, high contrast and low defect rate in the photolithography process.

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

[0084] Optionally, after the second step, the method further includes: drying the product by placing it in a hot plate for baking, and then rinsing it with water in a rinsing machine.

[0085] In this embodiment, the baking temperature can be 120-130°C and the baking time can be 5-8 minutes.

[0086] For example, a baking temperature of 125°C and a baking time of 6 minutes can enhance the adhesion of the photoresist and control the tilt angle of the photoresist.

[0087] The process involves rinsing the device with water for 15-20 minutes, for example, 18 minutes.

[0088] The third step is to sputter a thin metal film.

[0089] The sputtering distance for metal thin films is typically between 1 and 3 μm, for example, 2 μm.

[0090] Fifth step: Remove the mask pattern and the metal thin film on the mask pattern to obtain the metal reflective layer.

[0091] The part covered by the mask pattern is the part that does not need to be sputtered with metal, that is, the area corresponding to the through hole.

[0092] In this embodiment of the disclosure, the epitaxial wafer after the sputtering operation is completed undergoes two blue film stripping and adhesive removal processes.

[0093] In this embodiment of the disclosure, the epitaxial wafer is cleaned using ethanol.

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

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

[0096] For example, the distance between the sidewall of the through-hole in the metal reflective layer and the sidewall of the stepped structure is 8 micrometers.

[0097] In this embodiment of the disclosure, by designing a protective layer structure, the distance between the sidewall of the through hole in the metal reflective layer and the sidewall of the stepped structure is reduced to 8 micrometers compared to 14 micrometers in the related art, which greatly increases the area of ​​the metal reflective layer.

[0098] S26. A protective layer is made on the metal reflective layer; the protective layer covers the sidewall of the stepped structure and part of the stepped surface of the stepped structure; the protective layer has a third through hole and a fourth through hole; the third through hole is set on the metal reflective layer, and the fourth through hole is located on the stepped surface of the stepped structure.

[0099] In this embodiment, the protective layer can be an Al2O3 layer deposited by atomic layer deposition (ALD). For example, Al2O3 is deposited using single-atom deposition technology to obtain the protective layer. Using single-atom deposition technology to deposit the protective layer prevents silver migration, has a small area footprint, and can maximize the effective reflective area of ​​the metal reflective layer.

[0100] In this embodiment, the thickness of the protective layer can be 300 to 1000 angstroms. This thickness can both prevent silver migration and reduce the area occupied by the protective layer, thereby maximizing the effective reflective area of ​​the metal.

[0101] For example, Al2O3 layer deposition is performed in a single-atom-layer deposition machine.

[0102] For example, the protective layer is 500 angstroms.

[0103] S27. Make the first insulating layer.

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

[0105] For example, step S27 may include:

[0106] The first step is to use a vapor deposition process to create a SiO2 layer, thus obtaining the first insulating layer.

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

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

[0109] S28. Fabricate the first and second electrodes.

[0110] In the embodiments disclosed herein, 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] For example, the first electrode and the second electrode are a stack 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 stepped structure.

[0113] S29. Make the second insulating layer.

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

[0115] For example, step S29 may include:

[0116] The first step involves using a vapor deposition process to create a SiO2 layer, which forms the second insulating layer.

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

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

[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 and second insulating layers can be distributed Bragg reflector (DBR) layers.

[0121] The DBR layer can be a stack of at least one period of silicon oxide layer (e.g., SiO2) and titanium oxide layer (e.g., Ti3O5, Ti2O3).

[0122] S30, fabricate the first electrode pad and the second electrode pad.

[0123] The first electrode pad is connected to the first electrode through a second insulating layer through-hole at the first electrode, and the second electrode pad is connected to the second electrode through a second insulating layer through-hole at the second electrode.

[0124] In this embodiment of the disclosure, the first electrode pad and the second electrode pad can be a combination of one or more of the metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt, Au and AuSn produced by vapor deposition process.

[0125] For example, the first electrode pad and the second electrode pad are Cr, Al, AlCu, Ti, Ni, Pt, Au and AuSn stacks.

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

[0127] Compared to the LED structures provided by related technologies, the metal reflective layer area of ​​this disclosed embodiment is increased by 4.8%, and the product brightness is increased by 3%.

[0128] Figure 3 This is a schematic diagram of the structure of a light-emitting diode provided in an embodiment of this disclosure. See also... Figure 3The light-emitting diode includes: 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 stepped structure 201; a current blocking layer 105 and a metal reflective layer 106 are sequentially stacked on the epitaxial structure 10; the metal reflective layer 106 has a through-hole 2000 exposing the stepped 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 being located on the surface of the epitaxial structure 10, and the second through-hole 602 being located on the stepped surface of the stepped 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 layer covering the metal reflective layer 2000. A protective layer 107 is attached to the reflective layer. The protective layer 107 covers the sidewall of the stepped structure 201 and part of the stepped surface of the stepped structure 201. The protective layer 107 has a third through hole 171 and a fourth through hole 172. The third through hole 171 is disposed 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 stepped surface of the stepped structure 201, and the second electrode structure 402 is electrically connected to the extension structure 10 through the fourth through hole 172 and the second through hole 602.

[0130] In related technologies, preventing metal migration by wrapping a metal reflective layer with a protective layer sacrifices some linewidth and the area of ​​the metal reflective layer. In this embodiment, the protective layer covers a portion of the metal reflective layer, and specifically covers the sidewalls and part of the stepped surface of the stepped structure exposed by the through-holes in the metal reflective layer. That is, the protective layer extends from the metal reflective layer to the sidewalls of the stepped structure and then to part of the stepped surface, rather than wrapping the entire metal reflective layer. This reduces the number of through-holes in the metal reflective layer, decreases the distance between the sidewalls of the through-holes and the sidewalls of the stepped structure, increases the linewidth and area of ​​the metal reflective layer on the surface of the epitaxial structure, and improves the brightness of the light-emitting diode.

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

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

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

[0134] In this embodiment of the disclosure, by designing a protective layer structure, the distance between the sidewall of the through hole of the metal reflective layer 106 and the sidewall of the stepped structure 201 is reduced to 8 micrometers compared to 14 micrometers in the related art, which greatly increases the area of ​​the metal reflective layer.

[0135] In this embodiment of the disclosure, the through hole 2000 can be circular, and the radius of the through hole 2000 can be 25 to 32 micrometers (less than 33 micrometers in the related art), for example 27 micrometers.

[0136] In this embodiment of the disclosure, the step surface of the stepped structure can be circular with a radius of 15 to 20 micrometers, for example, 19 micrometers.

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

[0138] Optionally, the extension structure 10 also has an isolation groove (ISO) 202, and the insulation structure 30 also covers the isolation groove 202.

[0139] In this embodiment of the disclosure, the epitaxial structure 10 includes a first semiconductor layer 101, an active layer 102, and a second semiconductor layer 103.

[0140] In this configuration, a first semiconductor layer 101, an active layer 102, and a 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 have stepped structures 201 extending to the first semiconductor layer 101; that is, the stepped surfaces are located on the first semiconductor layer 101. The first semiconductor layer 101, the active layer 102, and the second semiconductor layer 103 also have isolation trenches 202 extending to the first semiconductor layer 101. In other examples, the isolation trenches may also be formed on the surface of the substrate 100.

[0141] In this embodiment of the disclosure, the substrate 100 can be any one of a sapphire substrate, a Si substrate, or a SiC substrate, and the material of the substrate 100 is not limited in this embodiment of the disclosure.

[0142] For example, substrate 100 is a sapphire substrate.

[0143] In this embodiment of the disclosure, the first semiconductor layer 101 can be an N-type semiconductor layer, and the second semiconductor layer 103 can be a P-type semiconductor layer.

[0144] For example, the first semiconductor layer 101 can be an N-type GaN layer, and the second semiconductor layer 103 can 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 this embodiment of the disclosure, the active layer 102 can be a multi-quantum well layer, such as an InGaN / GaN multi-quantum well structure.

[0147] Optionally, the light-emitting diode may also include a transparent conductive layer 104 located on the epitaxial structure 10, such as on the second semiconductor layer 103.

[0148] In this embodiment, the transparent conductive layer 104 can be an ITO layer. ITO has excellent transparency and conductivity, allowing light to pass through while also enabling good current conduction.

[0149] In this embodiment of the disclosure, the current blocking layer 105 can be a SiO2 layer.

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

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

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

[0153] Optionally, the insulating structure 30 further includes a first insulating layer 108, which covers the protective 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, which covers the second electrode 110 and the first insulating layer 108.

[0155] For example, both the first insulating layer 108 and the second insulating layer 109 can be SiO2 layers.

[0156] For example, both the first insulating layer 108 and the second insulating layer 109 can be DBR layers.

[0157] The DBR layer can be a stack of at least one period of silicon oxide layer (e.g., SiO2) and titanium oxide layer (e.g., Ti3O5, Ti2O3).

[0158] For example, 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] In this design, the first insulating layer 108 has through-holes 301 at the metal reflective layer 106 and the stepped structure 201. The first electrode 110 is connected to the metal reflective layer 106 through the through-holes 301 and 3 at the metal reflective layer 106, and the second electrode 111 is connected to the first semiconductor layer 101 through the through-holes 301 and 4 at the stepped structure 201. The second insulating layer 109 has through-holes 301 at the first electrode 110 and the second electrode 111. The first electrode pad 112 is connected to the first electrode 110 through the through-holes 302 at the first electrode 110, and the second electrode pad 113 is connected to the second electrode 111 through the through-holes 302 at the second electrode 111.

[0160] For example, the first electrode 110 and the second electrode 111 are Cr, Al, AlCu, Ti, Ni, Pt and Au stacks.

[0161] In this embodiment of the disclosure, the first electrode pad 112 and the second electrode pad 113 can be a combination of one or more of the metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt, Au and AuSn produced by vapor deposition process.

[0162] For example, the first electrode pad 112 and the second electrode pad 113 are Cr, Al, AlCu, Ti, Ni, Pt, Au and AuSn stacks.

[0163] It is worth noting that, in the embodiments of this disclosure, the structure can be selectively added or reduced based on the structure of the light-emitting diode described above, and this disclosure does not limit this.

[0164] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A method for fabricating a light-emitting diode, characterized in that, The method includes: Fabricate the epitaxial structure (10); The extension structure (10) is graphically processed to form a step structure (201), the step structure (201) including a step top surface, a step bottom surface and a side wall connecting the step top surface and the step bottom surface; A current blocking layer (105) is fabricated on the epitaxial structure (10). 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 top surface of the step of the stepped structure (201), and the second through hole (602) is located on the bottom surface of the step of the stepped structure (201). A metal reflective layer (106) is formed on the surface of the current blocking layer (105). The metal reflective layer (106) has a fifth through hole (2000) that exposes the bottom 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 distance between the sidewall of the fifth through hole (2000) and the sidewall of the step structure (201) is less than or equal to 11 micrometers. An insulating structure (30) is fabricated, the insulating structure (30) including a protective layer (107) covering the metal reflective layer (106), the protective layer (107) being in direct contact with the metal reflective layer (106); the protective layer (107) covering the sidewall of the stepped structure (201) and part of the bottom surface of the stepped structure (201); the protective layer (107) having a third through hole (171) and a fourth through hole (172); the third through hole (171) being disposed on the metal reflective layer (106), the fourth through hole (172) being located on the bottom surface of the stepped structure (201); the insulating structure (30) further includes a first insulating layer (108) and a second insulating layer (109), the first insulating layer (108) covering the protective layer (107) and the metal reflective layer (106), and the second insulating layer (109) covering the first insulating layer (108); A first electrode structure (401) and a second electrode structure (402) are fabricated. The first electrode structure (401) is electrically connected to the metal reflective layer (106) through the third through hole (171). 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 fabricating a light-emitting diode according to claim 1, characterized in that, A metal reflective layer (106) is formed on the surface of the current blocking layer (105), including: A layer of photoresist is coated on the surface of the current blocking layer (105); The photoresist is exposed and developed to obtain a mask pattern, which corresponds to the area where the fifth via (2000) is located; Sputtering metal thin films; Remove the mask pattern and the metal thin film on the mask pattern to obtain the metal reflective layer (106).

3. The method for fabricating a light-emitting diode according to claim 1 or 2, characterized in that, The fabrication of the insulating structure (30) includes: Al2O3 was deposited using single-atom deposition technology to obtain the protective layer (107).

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

5. A light-emitting diode, characterized in that, The light-emitting diode includes: 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 extension structure (10) has a stepped structure (201), the stepped structure (201) including a step top surface, a step bottom surface and a sidewall connecting the step top surface and the step bottom surface; The current blocking layer (105) and the metal reflective layer (106) are sequentially stacked on the epitaxial structure (10); The current blocking layer (105) has a first through hole (601) and a second through hole (602), the first through hole (601) being located on the top surface of the step of the stepped structure (201), and the second through hole (602) being located on the bottom surface of the step; The metal reflective layer (106) is electrically connected to the epitaxial structure (10) through the first through hole (601); The metal reflective layer (106) has a fifth through hole (2000) that exposes the bottom surface of the step structure (201), and the distance between the sidewall of the fifth through hole (2000) and the sidewall of the step structure (201) is less than or equal to 11 micrometers. The insulating structure (30) includes a protective layer (107) covering the metal reflective layer (106); the protective layer (107) is in direct contact with the metal reflective layer (106), and the protective layer (107) covers the sidewall of the stepped structure (201) and part of the bottom surface of the stepped structure (201); the protective layer (107) has a third through hole (171) and a fourth through hole (172); the insulating structure (30) also includes a first insulating layer (108) and a second insulating layer (109), the first insulating layer (108) covering the protective layer (107) and the metal reflective layer (106), and the second insulating layer (109) covering the first insulating layer (108); The third through hole (171) is disposed 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 bottom 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).

6. The light-emitting diode according to claim 5, characterized in that, The protective layer (107) is an Al2O3 layer.

7. The light-emitting diode according to claim 6, characterized in that, The thickness of the protective layer (107) is 300~1000 angstroms.

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