Light emitting diode and preparation method thereof

Abstract

The invention provides a light emitting diode and a preparation method thereof. The light emitting diode comprises an epitaxial structure, a silver mirror structure, an insulating structure, a first electrode and a second electrode. The first electrode and the second electrode comprise a first contact layer, a first reflection layer, a wrapping layer, a second reflection layer, a first adhesion layer, a reflection layer protection layer, a second adhesion layer, an electrode protection layer and a second contact layer which are stacked in sequence. Wherein the reflecting layer protection layer is used for protecting the first reflecting layer and the second reflecting layer, active reflecting metal in the first reflecting layer and the second reflecting layer is prevented from reacting with metal such as Au in the bonding pad, and the material melting point of the reflecting layer protection layer is higher than that of the first reflecting layer and that of the second reflecting layer. According to the invention, the light-emitting diode cannot be melted even if the temperature is high during working, so that the protection performance is more stable. The short circuit caused by the fracture of the insulation structure is avoided, and the LED yield 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 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 silver mirror structure, an insulating structure and an electrode structure.

[0004] Related Technology During the manufacturing process of light-emitting diodes, the insulating layer between the electrode structures is prone to cracking, causing a short circuit and electrode failure, thereby reducing the LED yield. 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 make the electrode structure more stable, avoid short circuit caused by cracking of the insulating layer, and improve the LED yield. 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 insulating structure, a first electrode and a second electrode;

[0007] The epitaxial structure is a step structure, and the silver mirror structure is located on the surface of the epitaxial structure; the first electrode is located on the surface of the silver mirror structure, and the second electrode is connected to the step surface of the step structure; the insulating structure covers the step structure, the silver mirror structure, the first electrode and the second electrode;

[0008] The first electrode and the second electrode include a first contact layer, a first reflective layer, a wrapping layer, a second reflective layer, a first adhesion layer, a reflective layer protective layer, a second adhesion layer, an electrode protective layer and a second contact layer stacked in sequence, the melting point of the material of the reflective layer protective layer is higher than the melting point of the material of the first reflective layer, and the melting point of the material of the reflective layer protective layer is higher than the melting point of the material of the second reflective layer.

[0009] Optionally, the first contact layer is a Cr layer, the first reflective layer is an Al layer, the wrapping layer includes a Ti sublayer and an AlCu alloy sublayer with an Al content of 10% stacked in sequence, the second reflective layer is an Al layer, the first adhesion layer is a Cr layer, the reflective layer protective layer is a Ni layer, the second adhesion layer is a Cr layer, the electrode protective layer is a Pt layer, and the second contact layer is a Ti layer.

[0010] Optionally, the thickness of the first contact layer is 40 to 60 angstroms, the thickness of the first reflective layer is 2500 to 3500 angstroms, the thickness of the Ti sublayer in the wrapping layer is 400 to 600 angstroms, the thickness of the AlCu alloy sublayer is 1500 to 2500 angstroms, the thickness of the second reflective layer is 1500 to 2500 angstroms, the thickness of the first adhesion layer is 100 to 200 angstroms, the thickness of the reflective layer protective layer is 2000 to 3000 angstroms, the thickness of the second adhesion layer is 100 to 200 angstroms, the thickness of the electrode protective layer is 1500 to 2500 angstroms, and the thickness of the second contact layer is 400 to 600 angstroms.

[0011] Optionally, the insulating structure includes a first insulating layer and a second insulating layer; the first insulating layer covers the silver mirror structure and the step structure, the first electrode passes through the first insulating layer to be connected to the silver mirror structure, and the second electrode passes through the first insulating layer to be connected to the step structure; the second insulating layer covers the first electrode, the second electrode and the first insulating layer;

[0012] The light emitting diode further includes: a first electrode pad and a second electrode pad, the first electrode pad passing through the second insulating layer and connected to the first electrode, the second electrode pad passing through the second insulating layer and connected to the second electrode;

[0013] The first electrode pad and the second electrode pad include an electrode pad contact layer, an electrode pad protection layer, and an electrode pad welding layer which are sequentially stacked.

[0014] Optionally, the first insulating layer and the second insulating layer are silicon dioxide layers, the electrode pad contact layer is a Ti layer, the electrode pad protection layer is a Ni layer, and the electrode pad welding layer is an AuSn layer.

[0015] Optionally, the thickness of the electrode pad contact layer is 100 to 200 angstroms, the thickness of the electrode pad protection layer is 2000 to 3000 angstroms, and the thickness of the electrode pad welding layer is 25000 to 35000 angstroms.

[0016] In another aspect, a method for preparing a light emitting diode comprises:

[0017] fabricating epitaxial structures;

[0018] Performing a patterning process on the epitaxial structure to form a step structure;

[0019] forming a silver mirror structure on the surface of the epitaxial structure, wherein the silver mirror structure is located on the surface of the epitaxial structure;

[0020] An insulating structure, a first electrode and a second electrode are manufactured, wherein the first electrode is located on the surface of the silver mirror structure, and the second electrode is connected to the step surface of the step structure; the insulating structure covers the step structure, the silver mirror structure, the first electrode and the second electrode; the first electrode and the second electrode include a first contact layer, a first reflective layer, a wrapping layer, a second reflective layer, a first adhesion layer, a reflective layer protective layer, a second adhesion layer, an electrode protective layer and a second contact layer stacked in sequence, wherein the melting point of the material of the reflective layer protective layer is higher than the melting point of the material of the first reflective layer, and the melting point of the material of the reflective layer protective layer is higher than the melting point of the material of the second reflective layer.

[0021] Optionally, the first contact layer is a Cr layer, the first reflective layer is an Al layer, the wrapping layer includes a Ti sublayer and an AlCu alloy sublayer with an Al content of 10% stacked in sequence, the second reflective layer is an Al layer, the first adhesion layer is a Cr layer, the reflective layer protective layer is a Ni layer, the second adhesion layer is a Cr layer, the electrode protective layer is a Pt layer, and the second contact layer is a Ti layer.

[0022] Optionally, the thickness of the first contact layer is 40 to 60 angstroms, the thickness of the first reflective layer is 2500 to 3500 angstroms, the thickness of the Ti sublayer in the wrapping layer is 400 to 600 angstroms, the thickness of the AlCu alloy sublayer is 1500 to 2500 angstroms, the thickness of the second reflective layer is 1500 to 2500 angstroms, the thickness of the first adhesion layer is 100 to 200 angstroms, the thickness of the reflective layer protective layer is 2000 to 3000 angstroms, the thickness of the second adhesion layer is 100 to 200 angstroms, the thickness of the electrode protective layer is 1500 to 2500 angstroms, and the thickness of the second contact layer is 400 to 600 angstroms.

[0023] Optionally, the evaporation rate of the first contact layer is 0.3 to 0.5 angstroms / s, the evaporation rate of the first reflective layer is 2 to 4 angstroms / s, the evaporation rate of the Ti sublayer in the encapsulating layer is 1 to 3 angstroms / s, the evaporation rate of the AlCu alloy sublayer is 4 to 6 angstroms / s, the evaporation rate of the second reflective layer is 5 to 7 angstroms / s, the evaporation rate of the first adhesion layer is 0.1 to 0.3 angstroms / s, the evaporation rate of the reflective layer protective layer is 4 to 6 angstroms / s, the evaporation rate of the second adhesion layer is 0.1 to 0.3 angstroms / s, the evaporation rate of the electrode protective layer is 1 to 3 angstroms / s, and the evaporation rate of the second contact layer is 1 to 3 angstroms / s.

[0024] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:

[0025] In the disclosed embodiment, the electrode includes a first contact layer, a first reflective layer, a wrapping layer, a second reflective layer, a first adhesion layer, a reflective layer protection layer, a second adhesion layer, an electrode protection layer and a second contact layer stacked in sequence. Among them, the first contact layer is used for ohmic contact between the electrode and the epitaxial structure; the second contact layer is used for contact with the pad; the first reflective layer and the second reflective layer can increase light reflection; the wrapping layer is used to cover and protect the first contact layer and the first reflective layer; the first adhesion layer and the second adhesion layer can make the layers in the electrode structure more closely bonded through adhesion; the electrode protection layer is used to protect the layers in the electrode. The reflective layer protection layer is used to protect the first reflective layer and the second reflective layer, and to prevent the active reflective metal in the first reflective layer and the second reflective layer from reacting with the metal such as Au in the pad, and because the melting point of the material of the reflective layer protection layer is higher than the melting point of the material of the first reflective layer and the second reflective layer, the light-emitting diode will not melt even at a high temperature during operation, and the protection performance is more stable. This avoids the formation of an alloy between Au in the pad and the reflective metal to cause the insulation structure to rupture, avoids the short circuit caused by the insulation structure rupture, and improves the LED yield. Furthermore, the electrode structure ensures the electrical properties of the electrode and the pad, thereby improving the performance of the LED. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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.

[0027] Figure 1 is a structural schematic diagram of a light emitting diode provided by an embodiment of the present disclosure;

[0028] Figure 2 is a schematic diagram of the structure of an electrode and an electrode pad provided by an embodiment of the present disclosure;

[0029] Figure 3 is a flow chart of a method for preparing a light emitting diode provided by an embodiment of the present disclosure;

[0030] Figure 4 This is a flow chart of another method for preparing a light emitting diode provided in an embodiment of the present disclosure.

[0031] The reference numerals are as follows:

[0032] 10: epitaxial structure; 20: silver mirror structure; 30: insulating structure;

[0033] 101: substrate; 102: first semiconductor layer; 103: active layer; 104: second semiconductor layer; 105: transparent conductive layer; 106: silver mirror reflection layer; 107: silver mirror protection layer; 108: first electrode; 109: first electrode pad; 110: second electrode; 111: second electrode pad; 112: first insulating layer; 113: second insulating layer; 115: isolation groove; 116: step structure;

[0034] 201: first contact layer; 202: first reflective layer; 203: wrapping layer; 204: second reflective layer; 205: first adhesion layer; 206: reflective layer protection layer; 207: second adhesion layer; 208: electrode protection layer; 209: second contact layer; 210: electrode pad contact layer; 211: electrode pad protection layer; 212: electrode pad welding layer;

[0035] 301: a through hole in the first insulating layer; 302: a through hole in the second insulating layer. DETAILED DESCRIPTION

[0036] 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.

[0037] Figure 1 is 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 includes: an epitaxial structure 10 , a silver mirror structure 20 , an insulating structure 30 , a first electrode 108 and a second electrode 110 .

[0038] The epitaxial structure 10 is in the form of a step structure 116, and the silver mirror structure 20 is located on the surface of the epitaxial structure 10; the first electrode 108 is located on the surface of the silver mirror structure 20, and the second electrode 110 is connected to the step surface of the step structure 116; the insulating structure 30 covers the step structure 116, the silver mirror structure 20, the first electrode 108 and the second electrode 110.

[0039] Figure 2 Schematic diagram of an electrode structure provided by an embodiment of the present disclosure. Figure 2 As shown, the first electrode 108 and the second electrode 110 include a first contact layer 201, a first reflective layer 202, a wrapping layer 203, a second reflective layer 204, a first adhesion layer 205, a reflective layer protection layer 206, a second adhesion layer 207, an electrode protection layer 208 and a second contact layer 209 stacked in sequence, the melting point of the material of the reflective layer protection layer 206 is higher than the melting point of the material of the first reflective layer 202, and the melting point of the material of the reflective layer protection layer 206 is higher than the melting point of the material of the second reflective layer 204.

[0040] In the disclosed embodiment, the first electrode and the second electrode include a first contact layer, a first reflective layer, a wrapping layer, a second reflective layer, a first adhesion layer, a first adhesion layer, a second adhesion layer, an electrode protection layer and a second contact layer stacked in sequence, wherein the first contact layer is used for ohmic contact between the electrode and the epitaxial structure; the second contact layer is used for contact with the pad; the first reflective layer and the second reflective layer can increase light reflection; the wrapping layer is used to cover and protect the first contact layer and the first reflective layer; the first adhesion layer and the second adhesion layer can make the layers in the electrode structure more closely bonded through adhesion; the electrode protection layer is used to protect the layers in the electrode. The reflective layer protection layer is used to protect the first reflective layer and the second reflective layer, and to prevent the active reflective metal in the first reflective layer and the second reflective layer from reacting with the metal such as Au in the pad, and because the melting point of the material of the reflective layer protection layer is higher than the melting point of the material of the first reflective layer and the second reflective layer, the light emitting diode will not melt even at a high temperature during operation, and the protection performance is more stable. This avoids the formation of an alloy between Au in the pad and the reflective metal to cause the insulation structure to break, avoids the short circuit caused by the insulation structure break, and improves the LED yield. Furthermore, the electrode structure ensures the electrical properties of the electrode and the pad, thereby improving the performance of the LED.

[0041] Optionally, the light emitting diode further includes a substrate 101 , and the epitaxial structure 10 is located on the substrate 101 .

[0042] Optionally, the epitaxial structure 10 is further provided with an isolation trench (ISO) 115 , and the first insulating layer 112 also covers the isolation trench 115 .

[0043] In the embodiment of the present disclosure, the first contact layer 201, the first reflective layer 202, the wrapping layer 203, the second reflective layer 204, the first adhesion layer 205, the reflective layer protection layer 206, the second adhesion layer 207, the electrode protection layer 208 and the second contact layer 209 can be manufactured by an evaporation process.

[0044] In the embodiment of the present disclosure, the first contact layer 201 may be a Cr layer. Cr has good electrical conductivity and can be used for ohmic contact between the electrode and the epitaxial structure.

[0045] In the embodiment of the present disclosure, the thickness of the first contact layer 201 can be 40 to 60 angstroms, and the evaporation rate can be 0.1 to 0.5 angstroms / s. The first contact layer of the above thickness can ensure conductivity while avoiding the effect of excessive thickness on the thickness of the entire LED; the first contact layer can be made at the above evaporation rate, so that the first contact layer can be deposited more evenly and the evaporation efficiency can be ensured.

[0046] For example, the thickness of the first contact layer 201 may be 50 angstroms, and the evaporation rate may be 0.2 angstroms / s.

[0047] In the embodiment of the present disclosure, the first reflective layer 202 may be an Al layer. Al has good reflectivity and conductivity, and improves light reflectivity while ensuring the electrical performance of the electrode.

[0048] In the disclosed embodiment, the thickness of the first reflective layer 202 can be 2900 to 3100 angstroms, and the evaporation rate can be 2 to 4 angstroms / s. The use of the first reflective layer of the above thickness can ensure the reflectivity while avoiding the effect of excessive thickness on the thickness of the entire LED; the use of the above evaporation rate to make the first reflective layer can deposit the first reflective layer more uniformly and ensure the evaporation efficiency.

[0049] Exemplarily, the first reflective layer 202 may be grown to a thickness of 3000 angstroms, and the evaporation rate may be 3 angstroms / s.

[0050] In the disclosed embodiment, the wrapping layer 203 may include a Ti sublayer and an AlCu alloy sublayer with an Al content of 10% stacked in sequence. Ti has good viscosity and can enhance adhesion, and the AlCu alloy with an Al content of 10% makes the evaporation process more stable, does not generate metal particles, avoids the rupture of the upper film layer, and improves the LED yield.

[0051] In the disclosed embodiment, the thickness of the Ti sublayer can be 400 to 600 angstroms, and the evaporation rate can be 1 to 3 angstroms / s. The use of the Ti sublayer of the above thickness can ensure adhesion while avoiding the effect of excessive thickness on the thickness of the entire LED; the use of the above evaporation rate to make the Ti sublayer can deposit the Ti sublayer more evenly and ensure the evaporation efficiency.

[0052] In the disclosed embodiment, the thickness of the AlCu alloy sublayer can be 1900-2100 angstroms, and the evaporation rate can be 4-6 angstroms / s. The AlCu alloy sublayer with the above thickness can ensure that the AlCu alloy sublayer has good thermal conductivity, which helps to dissipate heat while avoiding excessive thickness affecting the thickness of the entire LED; the AlCu alloy sublayer made with the above evaporation rate can be deposited more evenly and the evaporation efficiency is guaranteed.

[0053] For example, the thickness of the Ti sub-layer may be 500 angstroms, and the evaporation rate may be 2 angstroms / s. The thickness of the AlCu alloy sub-layer may be 2000 angstroms, and the evaporation rate may be 5 angstroms / s.

[0054] In the embodiment of the present disclosure, the second reflective layer 204 may be an Al layer. Al has good reflectivity and can improve the reflectivity of light.

[0055] In the disclosed embodiment, the thickness of the second reflective layer 204 can be 1900-2100 angstroms, and the evaporation rate can be 5-7 angstroms / s. The second reflective layer with the above thickness can ensure a higher reflectivity while avoiding the effect of excessive thickness on the thickness of the entire LED; the second reflective layer made with the above evaporation rate can deposit the second reflective layer more evenly and ensure the evaporation efficiency.

[0056] Exemplarily, the second reflective layer 204 may be 2000 angstroms, and the evaporation rate may be 6 angstroms / s.

[0057] In the embodiment of the present disclosure, the first adhesion layer 205 may be a Cr layer, which has good adhesion and reduces the risk of delamination and peeling.

[0058] In the disclosed embodiment, the thickness of the first adhesion layer 205 can be 100 to 200 angstroms, and the evaporation rate can be 0.1 to 0.3 angstroms / s. The first adhesion layer of the above thickness can ensure adhesion without making the electrode too thick; the first adhesion layer made by the above evaporation rate can deposit the first adhesion layer more evenly and ensure the evaporation efficiency.

[0059] For example, the first adhesion layer 205 may be 150 angstroms, and the evaporation rate may be 0.2 angstroms / s.

[0060] In the embodiment of the present disclosure, the reflective layer protection layer 206 may be a Ni layer. Ni has a higher melting point than Al and is inactive, so it can protect the reflective layer.

[0061] In the disclosed embodiment, the thickness of the reflective layer protective layer 206 can be 2400-2600 angstroms, and the evaporation rate can be 4-6 angstroms / s. The use of the reflective layer protective layer of the above thickness can ensure the improvement of the wear resistance of the overall structure of the electrode while avoiding the influence of the thickness of the entire LED by excessive thickness; the reflective layer protective layer produced by the above evaporation rate can make the thickness of the reflective layer protective layer more accurately controlled, the film quality is better and the preparation efficiency is higher.

[0062] Exemplarily, the thickness of the reflective layer protection layer 206 may be 2500 angstroms, and the evaporation rate may be 5 angstroms / s.

[0063] In this implementation, the Ni layer is used as a reflective layer and protective layer. Due to the high melting point of the Ni layer, the Ni layer can better block the direct contact between the Au in the electrode pad and the Al in the electrode, avoiding the formation of the Kirkendall effect (i.e., voids will be formed in the electrode pad), which will cause the electrode to expand and the insulating layer between the electrodes to rupture, thus avoiding short circuit and electrode failure, and improving the LED yield.

[0064] In the embodiment of the present disclosure, the second adhesion layer 207 may be a Cr layer. The Cr layer has good viscosity, which can improve the adhesion between the sub-layers and help prevent delamination and peeling.

[0065] In the disclosed embodiment, the thickness of the second adhesion layer 207 can be 100 to 200 angstroms, and the evaporation rate can be 0.1 to 0.3 angstroms / s. The use of the second adhesion layer of the above thickness can reduce the amount of material used without sacrificing adhesion, thereby achieving cost-effectiveness; the use of the second adhesion layer of the above evaporation rate can deposit the second adhesion layer more uniformly and ensure the evaporation efficiency.

[0066] For example, the second adhesion layer 207 may be 150 angstroms, and the evaporation rate may be 0.2 angstroms / s.

[0067] In the embodiment of the present disclosure, the electrode protection layer 208 may be a Pt layer. Pt is a very corrosion-resistant metal that can protect underlying materials from the effects of a corrosive environment.

[0068] In the disclosed embodiment, the thickness of the electrode protection layer 208 can be 1900-2100 angstroms, and the evaporation rate can be 1-3 angstroms / s. The electrode protection layer with the above thickness can optimize its physical properties such as corrosion resistance, electrical conductivity and thermal conductivity while avoiding the effect of excessive thickness on the thickness of the entire LED; the electrode protection layer produced with the above evaporation rate helps to achieve uniform coverage of the Pt layer and ensures a consistent film thickness on the entire substrate surface.

[0069] Exemplarily, the electrode protection layer 208 may be 150 angstroms, and the evaporation rate may be 0.2 angstroms / s.

[0070] In the embodiment of the present disclosure, the second contact layer 209 may be a Ti layer. The Ti layer has good viscosity and can enhance adhesion.

[0071] In the disclosed embodiment, the thickness of the second contact layer 209 can be 400 to 600 angstroms, and the evaporation rate can be 1 to 3 angstroms / s. The second contact layer of the above thickness can ensure optimized electrical connection, reduce contact resistance, and improve conductivity while avoiding excessive thickness affecting the thickness of the entire LED; the second contact layer 209 produced by the above evaporation rate helps to form a highly uniform film on the substrate, ensuring the consistency of the contact layer.

[0072] Exemplarily, the second contact layer 209 may be 500 angstroms, and the evaporation rate may be 2 angstroms / s.

[0073] See again Figure 1The insulating structure 30 includes a first insulating layer 112 and a second insulating layer 113; the first insulating layer 112 covers the silver mirror structure 20 and the step structure 116, the first electrode 108 passes through the first insulating layer 112 to be connected to the silver mirror structure 20, and the second electrode 110 passes through the first insulating layer 112 to be connected to the step structure 116; the second insulating layer 113 covers the first electrode 108, the second electrode 110 and the first insulating layer 112.

[0074] The light emitting diode may further include a first electrode pad 109 and a second electrode pad 111 . The first electrode pad 109 is connected to the first electrode 108 through the second insulating layer 113 , and the second electrode pad 111 is connected to the second electrode 110 through the second insulating layer 113 .

[0075] See again Figure 2 The first electrode pad 109 and the second electrode pad 111 include an electrode pad contact layer 210, an electrode pad protection layer 211 and an electrode pad welding layer 212 which are stacked in sequence.

[0076] In this implementation, the electrode pad contact layer is a Ti layer, which can improve the adhesion between the electrode pad and other material layers and help prevent delamination and peeling; the electrode pad protective layer is a Ni layer, which has good resistance to a variety of corrosive media and can protect the pad from corrosion; the electrode pad welding layer is an AuSn layer, which has good stability at high temperatures.

[0077] In the embodiment of the present disclosure, the electrode pad contact layer 210 may be a Ti layer, which may improve the adhesion between the electrode pad and other material layers, and help prevent delamination and peeling.

[0078] In the disclosed embodiment, the electrode pad contact layer 210 may have a thickness of 100 to 200 angstroms, and the evaporation rate may be 1 to 3 angstroms / s. The electrode pad contact layer of the above thickness can ensure optimized electrical connection, reduce contact resistance, and improve conductivity while avoiding excessive thickness affecting the thickness of the entire LED; the electrode pad contact layer produced using the above evaporation rate helps to form a highly uniform film on the substrate, ensuring the consistency of the contact layer.

[0079] Exemplarily, the electrode pad contact layer 210 may be 150 angstroms, and the evaporation rate may be 2 angstroms / s.

[0080] In the embodiment of the present disclosure, the electrode pad protection layer 211 may be a Ni layer. The Ni layer has good resistance to a variety of corrosive media and can protect the pad from corrosion.

[0081] In the disclosed embodiment, the electrode pad protection layer 211 may be 2000-3000 angstroms thick, and the evaporation rate may be 4-6 angstroms / s. The electrode pad protection layer of the above thickness can improve the wear resistance of the pad and reduce the risk of physical damage while avoiding the effect of excessive thickness on the thickness of the entire LED.

[0082] Exemplarily, the electrode pad protection layer 211 may be 2500 angstroms, and the evaporation rate may be 5 angstroms / s.

[0083] In the embodiment of the present disclosure, the electrode pad welding layer 212 may be an AuSn layer, and the AuSn welding layer has good stability at high temperatures.

[0084] In the disclosed embodiment, the electrode pad welding layer 212 may have a thickness of 25,000 to 35,000 angstroms, and the evaporation rate may be 5 to 15 angstroms / s. The electrode pad welding layer of the above thickness can provide better corrosion protection and extend the service life of the pad while avoiding the effect of excessive thickness on the thickness of the entire LED; the electrode pad welding layer produced by the above evaporation rate can shorten the production time and improve the production efficiency, especially in large-scale production.

[0085] Exemplarily, the electrode pad welding layer 212 may be 30,000 angstroms, and the evaporation rate may be 10 angstroms / s.

[0086] like Figure 2 As shown, the edges of the first electrode pad 109 and the second electrode pad 111 are placed on the second insulating layer 113, which can prevent the electrode pads from directly contacting the electrodes below, reduce damage caused by stress, and improve the LED yield.

[0087] In the embodiment of the present disclosure, the first insulating layer 112 and the second insulating layer 113 may be silicon dioxide layers.

[0088] In the embodiment of the present disclosure, the thickness of the first insulating layer 112 may be 4000-5000 angstroms.

[0089] Exemplarily, the first insulating layer 112 has a thickness of 4500 angstroms.

[0090] In the embodiment of the present disclosure, the thickness of the second insulating layer 113 may be 15000-20000 angstroms.

[0091] Exemplarily, the second insulating layer 113 has a thickness of 17500 angstroms.

[0092] In the embodiment of the present disclosure, the epitaxial structure 10 includes a first semiconductor layer 102 , an active layer 103 and a second semiconductor layer 104 .

[0093] The first semiconductor layer 102, the active layer 103, and the second semiconductor layer 104 are sequentially stacked on the substrate 101. The first semiconductor layer 102, the active layer 103, and the second semiconductor layer 104 are provided with a step structure 117 extending to the first semiconductor 102, that is, the step surface is located in the first semiconductor layer 102. The first semiconductor layer 102, the active layer 103, and the second semiconductor layer 104 are also provided with an isolation groove 115 extending to the surface of the first semiconductor layer 102.

[0094] In the embodiment of the present disclosure, the silver mirror structure 20 includes a transparent conductive layer 105 , a silver mirror reflection layer 106 and a silver mirror protection layer 107 .

[0095] The transparent conductive layer 105 , the silver mirror reflection layer 106 and the silver mirror protection layer 107 are sequentially stacked on the second semiconductor layer 104 , and the silver mirror protection layer 107 wraps the silver mirror reflection layer 106 .

[0096] In the disclosed embodiment, the transparent conductive layer 105 may be an indium tin oxide (ITO) layer, which is manufactured by a sputtering process. ITO has excellent transparency and conductivity, and it allows light to pass through while conducting current to form an electrical connection.

[0097] In the embodiment of the present disclosure, the thickness of the transparent conductive layer 105 may be 100 to 300 angstroms.

[0098] Exemplarily, the transparent conductive layer 105 may have a thickness of 200 angstroms.

[0099] In the embodiment of the present disclosure, the silver mirror reflection layer 106 may be a combination of one or more metal or alloy layers such as Ag, Ni, Ti, TiW, etc.

[0100] Exemplarily, the silver mirror reflection layer 106 is a stack of Ag, Ni, Ti and TiW.

[0101] In the embodiment of the present disclosure, the silver mirror protection layer 107 may be a combination of one or more metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt and Au.

[0102] Exemplarily, the silver mirror protection layer 107 is a stack of Cr, Al, AlCu, Ti, Ni, Pt, and Au.

[0103] In the embodiment of the present disclosure, the substrate 101 may be any one of substrates such as a sapphire substrate, a Si substrate, and a SiC substrate. The embodiment of the present disclosure does not limit the material of the substrate 101.

[0104] Exemplarily, the substrate 101 is a sapphire substrate.

[0105] In the embodiment of the present disclosure, the first semiconductor layer 102 may be an N-type semiconductor layer, and the second semiconductor layer 104 may be a P-type semiconductor layer.

[0106] For example, the first semiconductor layer 102 may be an N-type GaN layer, and the second semiconductor layer 104 may be a P-type GaN layer.

[0107] In other embodiments, the first semiconductor layer 102 may be a P-type semiconductor layer, and the second semiconductor layer 104 may be an N-type semiconductor layer.

[0108] In the embodiment of the present disclosure, the active layer 103 may be a multi-quantum well layer, such as an InGaN / GaN multi-quantum well structure.

[0109] 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.

[0110] Figure 3 is a flow chart of a method for preparing a light emitting diode provided by an embodiment of the present disclosure. Figure 3 The method steps include:

[0111] S11. Fabricating an epitaxial structure.

[0112] S12, performing graphic processing on the epitaxial structure to form a step structure.

[0113] S13. Forming a silver mirror structure on the surface of the epitaxial structure, wherein the silver mirror structure is located on the surface of the epitaxial structure.

[0114] S14. Make an insulating structure, a first electrode and a second electrode, wherein the first electrode is located on the surface of the silver mirror structure, and the second electrode is connected to the step surface of the step structure; the insulating structure covers the step structure, the silver mirror structure, the first electrode and the second electrode; the first electrode and the second electrode include a first contact layer, a first reflective layer, a wrapping layer, a second reflective layer, a first adhesion layer, a reflective layer protective layer, a second adhesion layer, an electrode protective layer and a second contact layer stacked in sequence, the melting point of the material of the reflective layer protective layer is higher than the melting point of the material of the first reflective layer, and the melting point of the material of the reflective layer protective layer is higher than the melting point of the material of the second reflective layer.

[0115] In the disclosed embodiment, the first electrode and the second electrode include a first contact layer, a first reflective layer, a wrapping layer, a second reflective layer, a first adhesion layer, a first adhesion layer, a second adhesion layer, an electrode protection layer and a second contact layer stacked in sequence, wherein the first contact layer is used for ohmic contact between the electrode and the epitaxial structure; the second contact layer is used for contact with the pad; the first reflective layer and the second reflective layer can increase light reflection; the wrapping layer is used to cover and protect the first contact layer and the first reflective layer; the first adhesion layer and the second adhesion layer can make the layers in the electrode structure more closely bonded through adhesion; the electrode protection layer is used to protect the layers in the electrode. The reflective layer protection layer is used to protect the first reflective layer and the second reflective layer, and to prevent the active reflective metal in the first reflective layer and the second reflective layer from reacting with the metal such as Au in the pad, and because the melting point of the material of the reflective layer protection layer is higher than the melting point of the material of the first reflective layer and the second reflective layer, the light emitting diode will not melt even at a high temperature during operation, and the protection performance is more stable. This avoids the formation of an alloy between Au in the pad and the reflective metal to cause the insulation structure to break, avoids the short circuit caused by the insulation structure break, and improves the LED yield. Furthermore, the electrode structure ensures the electrical properties of the electrode and the pad, thereby improving the performance of the LED.

[0116] Figure 4 is a flow chart of another method for preparing a light emitting diode provided by an embodiment of the present disclosure. Figure 4 The method steps include:

[0117] 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.

[0118] The substrate may be any one of a sapphire substrate, a Si substrate, a SiC substrate and the like.

[0119] Exemplarily, the substrate 101 is a sapphire substrate.

[0120] In one example, step S21 includes:

[0121] The first step is to make the first semiconductor layer.

[0122] In the embodiment of the present disclosure, the first semiconductor layer is an N-type GaN layer.

[0123] The second step is to make the active layer.

[0124] In the embodiment of the present disclosure, the active layer is a multi-quantum well layer, such as an InGaN / GaN multi-quantum well structure.

[0125] The third step is to make the second semiconductor layer.

[0126] In the embodiment of the present disclosure, the second semiconductor layer is a P-type GaN layer.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] In the disclosed embodiment, the first semiconductor layer, the active layer, and the second semiconductor layer are sequentially stacked on the substrate. The first semiconductor layer, the active layer, and the second semiconductor layer are provided with a step structure extending to the first semiconductor, 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 surface of the first semiconductor layer.

[0131] Exemplarily, step S22 may include:

[0132] 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 extending to the first semiconductor layer and an isolation groove extending to the substrate.

[0133] S23. Forming a silver mirror structure on the surface of the epitaxial structure.

[0134] In the embodiment of the present disclosure, this step may include:

[0135] In the first step, a transparent conductive layer is formed on the second semiconductor layer.

[0136] The transparent conductive layer may be an ITO layer with a thickness of 100 to 300 angstroms. ITO has good transparency and conductivity, and can allow light to pass through while conducting current to form an electrical connection.

[0137] Exemplarily, making the transparent conductive layer may include:

[0138] A layer of ITO film is sputtered; and the ITO film is patterned to obtain an ITO layer.

[0139] The patterning of the ITO film may include: spin coating photoresist; forming a mask pattern by exposure and development; and wet etching the ITO film under the protection of the mask pattern.

[0140] Exemplarily, the thickness of the transparent conductive layer may be 200 angstroms.

[0141] The second step is to make a silver mirror reflective layer on the transparent conductive layer.

[0142] In the disclosed embodiment, the silver mirror reflective layer is a silver mirror layer made by an evaporation process, and may be a combination of one or more metal or alloy layers such as Ag, Ni, Ti, and TiW.

[0143] Exemplarily, the silver mirror reflective layer is a stack of Ag, Ni, Ti and TiW.

[0144] The third step is to make a silver mirror protective layer on the silver mirror reflective layer.

[0145] In the embodiment of the present disclosure, the silver mirror protection layer may be a combination of one or more metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt and Au.

[0146] Exemplarily, the silver mirror protection layer 107 is a stack of Cr, Al, AlCu, Ti, Ni, Pt, and Au.

[0147] S24, making a first insulating layer.

[0148] Wherein, the first insulating layer covers the silver mirror structure, the isolation groove and the step structure.

[0149] Exemplarily, this step may include:

[0150] In the first step, a SiO2 layer is produced by a vapor deposition process, and the vapor deposition thickness can be 4000 to 5000 angstroms.

[0151] Exemplarily, the thickness of the first insulating layer is 4500 angstroms.

[0152] The second step is to perform patterning on the SiO2 layer and open a through hole in the first insulating layer.

[0153] Wherein, the first insulating layer has first insulating layer through holes respectively opened at the protection layer and the step structure.

[0154] S25, manufacturing a first electrode and a second electrode.

[0155] The first electrode is connected to the protective layer through a first insulating layer through-hole at the protective layer, and the second electrode is connected to the first semiconductor layer through a first insulating layer through-hole at the step structure.

[0156] In the embodiment of the present disclosure, the first electrode and the second electrode include a first contact layer, a first reflective layer, a wrapping layer, a second reflective layer, a first adhesion layer, a first adhesion layer, a second adhesion layer, an electrode protection layer and a second contact layer stacked in sequence.

[0157] In the embodiment of the present disclosure, the first contact layer, the first reflective layer, the wrapping layer, the second reflective layer, the first adhesive layer, the first adhesive layer, the second adhesive layer, the electrode protection layer and the second contact layer can be made by an evaporation process. That is, step S25 may include:

[0158] The first contact layer, the first reflective layer, the wrapping layer, the second reflective layer, the first adhesion layer, the first adhesion layer, the second adhesion layer, the electrode protection layer and the second contact layer are sequentially evaporated.

[0159] In the embodiment of the present disclosure, the first contact layer may be a Cr layer. Cr has good conductivity and can be used for ohmic contact between the electrode and the epitaxial structure.

[0160] In the embodiment of the present disclosure, the thickness of the first contact layer can be 40 to 60 angstroms, and the evaporation rate can be 0.1 to 0.5 angstroms / s. Using the first contact layer with the above thickness can ensure conductivity while avoiding excessive thickness affecting the thickness of the entire LED; using the above evaporation rate to make the first contact layer can deposit the first contact layer more evenly and ensure the evaporation efficiency.

[0161] For example, the thickness of the first contact layer may be 50 angstroms, and the evaporation rate may be 0.2 angstroms / s.

[0162] In the embodiment of the present disclosure, the first reflective layer may be an Al layer. Al has good reflectivity and conductivity, and improves light reflectivity while ensuring the electrical performance of the electrode.

[0163] In the embodiment of the present disclosure, the thickness of the first reflective layer can be 2900 to 3100 angstroms, and the evaporation rate can be 2 to 4 angstroms / s. The use of the first reflective layer with the above thickness can ensure the reflectivity while avoiding the excessive thickness affecting the thickness of the entire LED; the use of the above evaporation rate to produce the first reflective layer can more evenly deposit the first reflective layer and ensure the evaporation efficiency.

[0164] Exemplarily, the growth thickness of the first reflective layer may be 3000 angstroms, and the evaporation rate may be 3 angstroms / s.

[0165] In the embodiment of the present disclosure, the wrapping layer may include a Ti sublayer and a 10% AlCu alloy sublayer stacked in sequence. The Ti layer has good viscosity and can enhance adhesion. The AlCu alloy with an Al content of 10% makes the evaporation process more stable, does not produce metal particles, avoids rupture of the upper film layer, and improves the LED yield.

[0166] In the disclosed embodiment, the thickness of the Ti sublayer can be 400 to 600 angstroms, and the evaporation rate can be 1 to 3 angstroms / s. The thickness of the AlCu alloy sublayer can be 1900 to 2100 angstroms, and the evaporation rate can be 4 to 6 angstroms / s. By using the above thickness of the Ti sublayer, it is possible to ensure adhesion while avoiding excessive thickness affecting the thickness of the entire LED; by using the above evaporation rate to make the Ti sublayer, the Ti sublayer can be deposited more evenly and the evaporation efficiency can be ensured; by using the above thickness of the AlCu alloy sublayer, it is possible to ensure that the AlCu alloy sublayer has good thermal conductivity, which helps to dissipate heat while avoiding excessive thickness affecting the thickness of the entire LED; by using the above evaporation rate to make the AlCu alloy sublayer, the AlCu alloy sublayer can be deposited more evenly and the evaporation efficiency can be ensured.

[0167] For example, the thickness of the Ti sub-layer may be 500 angstroms, and the evaporation rate may be 2 angstroms / s. The thickness of the AlCu alloy sub-layer may be 2000 angstroms, and the evaporation rate may be 5 angstroms / s.

[0168] In the embodiment of the present disclosure, the second reflective layer may be an Al layer. Al has good reflectivity and can improve the reflectivity of light.

[0169] In the disclosed embodiment, the thickness of the second reflective layer can be 1900-2100 angstroms, and the evaporation rate can be 5-7 angstroms / s. The second reflective layer with the above thickness can ensure a higher reflectivity while avoiding the effect of excessive thickness on the thickness of the entire LED; the second reflective layer made with the above evaporation rate can deposit the second reflective layer more evenly and ensure the evaporation efficiency.

[0170] Exemplarily, the second reflective layer may be 2000 angstroms, and the evaporation rate may be 6 angstroms / s.

[0171] In the embodiment of the present disclosure, the first adhesion layer may be a Cr layer, which has good adhesion and reduces the risk of delamination and peeling.

[0172] In the disclosed embodiment, the thickness of the first adhesion layer can be 100 to 200 angstroms, and the evaporation rate can be 0.1 to 0.3 angstroms / s. The first adhesion layer with the above thickness can ensure adhesion without making the electrode too thick; the first adhesion layer made with the above evaporation rate can deposit the first adhesion layer more evenly and ensure evaporation efficiency.

[0173] For example, the first adhesion layer may be 150 angstroms, and the evaporation rate may be 0.2 angstroms / s.

[0174] In the embodiment of the present disclosure, the reflective layer protective layer may be a Ni layer. Ni has a higher melting point than Al and is inactive, so it can protect the reflective layer.

[0175] In the disclosed embodiment, the thickness of the reflective layer protective layer can be 2400-2600 angstroms, and the evaporation rate can be 4-6 angstroms / s. The use of the reflective layer protective layer of the above thickness can ensure the improvement of the wear resistance of the overall structure of the electrode while avoiding the influence of excessive thickness on the thickness of the entire LED; the reflective layer protective layer produced by the above evaporation rate can make the thickness control of the reflective layer protective layer more precise, the film quality is better and the preparation efficiency is higher.

[0176] Exemplarily, the reflective layer protective layer may be 2500 angstroms, and the evaporation rate may be 5 angstroms / s.

[0177] In this implementation, a Ni layer is added to the adhesion layer of the electrode as a protective layer. Due to the high melting point of the Ni layer, the Ni layer can better block the direct contact between the Au in the electrode pad and the Al in the electrode, avoiding the formation of the Kirkendall effect (i.e., voids will be formed in the electrode pad), which will cause the electrode to expand and the insulating layer between the electrodes to rupture, thereby avoiding short circuit and electrode failure, and improving the LED yield.

[0178] In the embodiment of the present disclosure, the second adhesion layer may be a Cr layer. The Cr layer has good viscosity, can improve the adhesion between the sub-layers, and helps prevent delamination and peeling.

[0179] In the disclosed embodiment, the thickness of the second adhesive layer can be 100 to 200 angstroms, and the evaporation rate can be 0.1 to 0.3 angstroms / s. The use of the second adhesive layer of the above thickness can reduce the amount of material used without sacrificing adhesion, thereby achieving cost-effectiveness; the use of the second adhesive layer of the above evaporation rate can deposit the second adhesive layer more uniformly and ensure evaporation efficiency.

[0180] For example, the second adhesion layer may be 150 angstroms, and the evaporation rate may be 0.2 angstroms / s.

[0181] In the embodiment of the present disclosure, the electrode protection layer may be a Pt layer, which is a very corrosion-resistant metal that can protect the underlying material from the influence of the corrosive environment.

[0182] In the disclosed embodiment, the thickness of the electrode protection layer can be 1900 to 2100 angstroms, and the evaporation rate can be 1 to 3 angstroms / s. The electrode protection layer of the above thickness is used to optimize its physical properties such as corrosion resistance, electrical conductivity and thermal conductivity while avoiding excessive thickness affecting the thickness of the entire LED; the electrode protection layer produced by the above evaporation rate helps to achieve uniform coverage of the Pt layer and ensures that the film thickness of the entire substrate surface is consistent.

[0183] Exemplarily, the electrode protection layer may be 150 angstroms, and the evaporation rate may be 0.2 angstroms / s.

[0184] In the embodiment of the present disclosure, the second contact layer may be a Ti layer, which has good adhesion.

[0185] In the disclosed embodiment, the thickness of the second contact layer can be 400 to 600 angstroms, and the evaporation rate can be 1 to 3 angstroms / s. The second contact layer of the above thickness can ensure optimized electrical connection, reduce contact resistance, and improve conductivity while avoiding excessive thickness affecting the thickness of the entire LED; the second contact layer produced by the above evaporation rate helps to form a highly uniform film on the substrate, ensuring the consistency of the contact layer.

[0186] Exemplarily, the second contact layer may be 500 angstroms, and the evaporation rate may be 2 angstroms / s.

[0187] S26, making a second insulating layer.

[0188] Exemplarily, this step may include:

[0189] In the first step, a SiO2 layer is produced by a vapor deposition process, and the vapor deposition thickness can be 15000-20000 angstroms.

[0190] Exemplarily, the evaporated thickness of the second insulating layer is 17500 angstroms.

[0191] The second step is to perform patterning on the SiO2 layer and open a through hole in the second insulating layer.

[0192] The second insulating layer has first insulating layer through holes respectively at the first electrode and the second electrode.

[0193] S27, manufacturing a first electrode pad and a second electrode pad.

[0194] In the embodiment of the present disclosure, the first electrode pad is connected to the first electrode through the second insulating layer, and the second electrode pad is connected to the second electrode through the second insulating layer. The first electrode pad and the second electrode pad include an electrode pad contact layer, an electrode pad protection layer and an electrode pad welding layer stacked in sequence.

[0195] In this implementation, the electrode pad contact layer is a Ti layer, which can improve the adhesion between the electrode pad and other material layers and help prevent delamination and peeling; the electrode pad protective layer is a Ni layer, which has good resistance to a variety of corrosive media and can protect the pad from corrosion; the electrode pad welding layer is an AuSn layer, which has good stability at high temperatures.

[0196] In the embodiment of the present disclosure, the electrode pad contact layer may be a Ti layer, which may improve the adhesion between the electrode pad and other material layers, and help prevent delamination and peeling.

[0197] In the disclosed embodiment, the thickness of the electrode pad contact layer can be 100 to 200 angstroms, and the evaporation rate can be 1 to 3 angstroms / s. The electrode pad contact layer with the above thickness can ensure optimized electrical connection, reduce contact resistance, improve conductivity, and avoid excessive thickness affecting the thickness of the entire LED; the electrode pad contact layer produced with the above evaporation rate helps to form a highly uniform film on the substrate, ensuring the consistency of the contact layer.

[0198] Exemplarily, the electrode pad contact layer may be 150 angstroms, and the evaporation rate may be 2 angstroms / s.

[0199] In the disclosed embodiment, the electrode pad protection layer may be a Ni layer, which has good resistance to a variety of corrosive media and can protect the pad from corrosion.

[0200] In the disclosed embodiment, the thickness of the electrode pad protection layer can be 2000-3000 angstroms, and the evaporation rate can be 4-6 angstroms / s. The electrode pad protection layer of the above thickness can ensure the improvement of the wear resistance of the pad, reduce the risk of physical damage, and avoid the thickness being too large to affect the thickness of the entire LED.

[0201] Exemplarily, the electrode pad protection layer may be 2500 angstroms, and the evaporation rate may be 5 angstroms / s.

[0202] In the embodiment of the present disclosure, the electrode pad welding layer may be an AuSn layer, and the AuSn welding layer has good stability at high temperatures.

[0203] In the disclosed embodiment, the electrode pad welding layer may have a thickness of 25,000 to 35,000 angstroms, and the evaporation rate may be 5 to 15 angstroms / s. The electrode pad welding layer of the above thickness can provide better corrosion protection, extend the service life of the pad, and avoid the thickness of the LED being affected by excessive thickness; the electrode pad welding layer produced by the above evaporation rate helps to shorten the production time and improve the production efficiency, especially in large-scale production.

[0204] Exemplarily, the electrode pad welding layer may be 30,000 angstroms, and the evaporation rate may be 10 angstroms / s.

[0205] Table 1 is a comparison table of failed chips under high temperature load conditions between the electrode structure provided by the embodiment of the present disclosure and the related art. As shown in Table 1, the electrode structure provided by the related art failed two LEDs after aging under high temperature load for 500 hours, while the electrode structure provided by the embodiment of the present disclosure did not fail after aging under high temperature load for 1000 hours. It can be seen that the electrode structure provided by the embodiment of the present disclosure solves the problem of forming gold-aluminum alloy well and has high reliability.

[0206] Table 1

[0207]

[0208] 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 insulating structure (30), a first electrode (108) and a second electrode (110); The epitaxial structure (10) is in the form of a step structure (116), and the silver mirror structure (20) is located on the surface of the epitaxial structure (10); the first electrode (108) is located on the surface of the silver mirror structure (20), and the second electrode (110) is connected to the step surface of the step structure (116); the insulating structure (30) covers the step structure (116), the silver mirror structure (20), the first electrode (108) and the second electrode (110); The first electrode (108) and the second electrode (110) include a first contact layer (201), a first reflective layer (202), a wrapping layer (203), a second reflective layer (204), a first adhesion layer (205), a reflective layer protection layer (206), a second adhesion layer (207), an electrode protection layer (208) and a second contact layer (209) stacked in sequence, wherein the melting point of the material of the reflective layer protection layer (206) is higher than the melting point of the material of the first reflective layer (202), and the melting point of the material of the reflective layer protection layer (206) is higher than the melting point of the material of the second reflective layer (204).

2. The light emitting diode according to claim 1, characterized in that: The first contact layer (201) is a Cr layer, the first reflective layer (202) is an Al layer, the wrapping layer (203) comprises a Ti sublayer and an AlCu alloy sublayer with an Al content of 10% stacked in sequence, the second reflective layer (204) is an Al layer, the first adhesion layer (205) is a Cr layer, the reflective layer protection layer (206) is a Ni layer, the second adhesion layer (207) is a Cr layer, the electrode protection layer (208) is a Pt layer, and the second contact layer (209) is a Ti layer.

3. The light emitting diode according to claim 2, characterized in that: The thickness of the first contact layer (201) is 40 to 60 angstroms, the thickness of the first reflective layer (202) is 2500 to 3500 angstroms, the thickness of the Ti sublayer in the wrapping layer (203) is 400 to 600 angstroms, the thickness of the AlCu alloy sublayer is 1500 to 2500 angstroms, the thickness of the second reflective layer (204) is 1500 to 2500 angstroms, the thickness of the first adhesion layer (205) is 100 to 200 angstroms, the thickness of the reflective layer protection layer (206) is 2000 to 3000 angstroms, the thickness of the second adhesion layer (207) is 100 to 200 angstroms, the thickness of the electrode protection layer (208) is 1500 to 2500 angstroms, and the thickness of the second contact layer (209) is 400 to 600 angstroms.

4. The light emitting diode according to any one of claims 1 to 3, characterized in that: The insulating structure (30) comprises a first insulating layer (112) and a second insulating layer (113); the first insulating layer (112) covers the silver mirror structure (20) and the step structure (116); the first electrode (108) passes through the first insulating layer (112) to be connected to the silver mirror structure (20); the second electrode (110) passes through the first insulating layer (112) to be connected to the step structure (116); the second insulating layer (113) covers the first electrode (108), the second electrode (110) and the first insulating layer (112); The light emitting diode further comprises: a first electrode pad (109) and a second electrode pad (111), wherein the first electrode pad (109) passes through the second insulating layer (113) to be connected to the first electrode (108), and the second electrode pad (111) passes through the second insulating layer (113) to be connected to the second electrode (110); The first electrode pad (109) and the second electrode pad (111) include an electrode pad contact layer (210), an electrode pad protection layer (211) and an electrode pad welding layer (212) which are stacked in sequence.

5. The light emitting diode according to claim 4, characterized in that: The electrode pad contact layer (210) is a Ti layer, the electrode pad protection layer (211) is a Ni layer, and the electrode pad welding layer (212) is an AuSn layer.

6. The light emitting diode according to claim 5, characterized in that: The thickness of the electrode pad contact layer (210) is 100 to 200 angstroms, the thickness of the electrode pad protection layer (211) is 2000 to 3000 angstroms, and the thickness of the electrode pad welding layer (212) is 25000 to 35000 angstroms.

7. 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; forming a silver mirror structure on the surface of the epitaxial structure, wherein the silver mirror structure is located on the surface of the epitaxial structure; An insulating structure, a first electrode and a second electrode are manufactured, wherein the first electrode is located on the surface of the silver mirror structure, and the second electrode is connected to the step surface of the step structure; the insulating structure covers the step structure, the silver mirror structure, the first electrode and the second electrode; the first electrode and the second electrode include a first contact layer, a first reflective layer, a wrapping layer, a second reflective layer, a first adhesion layer, a reflective layer protective layer, a second adhesion layer, an electrode protective layer and a second contact layer stacked in sequence, wherein the melting point of the material of the reflective layer protective layer is higher than the melting point of the material of the first reflective layer, and the melting point of the material of the reflective layer protective layer is higher than the melting point of the material of the second reflective layer.

8. The method for preparing a light emitting diode according to claim 7, characterized in that: The first contact layer is a Cr layer, the first reflective layer is an Al layer, the wrapping layer includes a Ti sublayer and an AlCu alloy sublayer with an Al content of 10% stacked in sequence, the second reflective layer is an Al layer, the first adhesion layer is a Cr layer, the reflective layer protective layer is a Ni layer, the second adhesion layer is a Cr layer, the electrode protective layer is a Pt layer, and the second contact layer is a Ti layer.

9. The method for preparing a light emitting diode according to claim 8, characterized in that: The thickness of the first contact layer is 40 to 60 angstroms, the thickness of the first reflective layer is 2500 to 3500 angstroms, the thickness of the Ti sublayer in the wrapping layer is 400 to 600 angstroms, the thickness of the AlCu alloy sublayer is 1500 to 2500 angstroms, the thickness of the second reflective layer is 1500 to 2500 angstroms, the thickness of the first adhesion layer is 100 to 200 angstroms, the thickness of the reflective layer protective layer is 2000 to 3000 angstroms, the thickness of the second adhesion layer is 100 to 200 angstroms, the thickness of the electrode protective layer is 1500 to 2500 angstroms, and the thickness of the second contact layer is 400 to 600 angstroms.

10. The method for preparing a light emitting diode according to claim 8, characterized in that: The evaporation rate of the first contact layer is 0.3 to 0.5 angstroms / s, the evaporation rate of the first reflective layer is 2 to 4 angstroms / s, the evaporation rate of the Ti sublayer in the encapsulating layer is 1 to 3 angstroms / s, the evaporation rate of the AlCu alloy sublayer is 4 to 6 angstroms / s, the evaporation rate of the second reflective layer is 5 to 7 angstroms / s, the evaporation rate of the first adhesion layer is 0.1 to 0.3 angstroms / s, the evaporation rate of the reflective layer protective layer is 4 to 6 angstroms / s, the evaporation rate of the second adhesion layer is 0.1 to 0.3 angstroms / s, the evaporation rate of the electrode protective layer is 1 to 3 angstroms / s, and the evaporation rate of the second contact layer is 1 to 3 angstroms / s.

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