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 a reflecting layer, an epitaxial structure, a current expansion layer and a first electrode, the epitaxial structure and the current expansion layer are sequentially stacked on the reflecting layer, and the first electrode is located on the current expansion layer; a groove structure is formed in the face, away from the current expansion layer, of the first electrode, the depth of the groove structure is smaller than 35% of the thickness of the first electrode, and the area of the groove structure is smaller than 20% of the area of the face, away from the current expansion layer, of the first electrode. The groove structure is arranged on the surface, far away from the current expansion layer, of the first electrode, so that the shading area caused by deformation is reduced, and the brightness of the light-emitting diode is improved. Meanwhile, the area proportion and the depth proportion of the groove structure are limited, and the situation that due to the fact that the area of the groove structure is too large or the depth is too large, the mechanical strength of the electrode is low, and abnormal deformation occurs is avoided.

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] A light emitting diode (LED) is a semiconductor device that can emit light and is widely used in lighting, display, traffic signals, medical equipment and many other fields.

[0003] The related technology provides a light-emitting diode, the light-emitting diode structure includes a reflective layer, an epitaxial structure, a current spreading layer and a first electrode, the epitaxial structure and the current spreading layer are sequentially stacked on the reflective layer, and the first electrode is located on the current spreading layer.

[0004] Related technology: When packaging the light-emitting diode of the above structure, it is necessary to weld a conductive wire on the first electrode. During the welding process, the first electrode is squeezed and deformed due to pressure and power, thereby increasing the electrode shading area, resulting in a decrease in the brightness of the light-emitting diode. Summary of the invention

[0005] The embodiment of the present disclosure provides a light emitting diode and a method for manufacturing the same, which reduces the risk of electrode shedding and improves the brightness of the light emitting diode. The technical solution is as follows:

[0006] In one aspect, a light emitting diode is provided, comprising: a reflective layer, an epitaxial structure, a current spreading layer and a first electrode, wherein the epitaxial structure and the current spreading layer are sequentially stacked on the reflective layer, and the first electrode is located on the current spreading layer;

[0007] A groove structure is formed on one side of the first electrode away from the current spreading layer, the depth of the groove structure is less than 35% of the thickness of the first electrode, and the area of ​​the groove structure is less than 20% of the area of ​​the side of the first electrode away from the current spreading layer.

[0008] Optionally, the depth of the groove structure is 20-30% of the thickness of the first electrode.

[0009] Optionally, the area of ​​the groove structure is 10-15% of the area of ​​a side of the first electrode away from the current spreading layer.

[0010] Optionally, the groove structure includes a plurality of strip-shaped grooves extending from the middle to the edge of the first electrode.

[0011] Optionally, the cross-section of the strip-shaped groove is an inverted trapezoid.

[0012] Optionally, the first electrode is an AlCu alloy electrode.

[0013] Optionally, a current blocking groove is opened on the surface of the epitaxial structure, the current expansion layer covers the current blocking groove, and the first electrode is correspondingly arranged in the current blocking groove.

[0014] In another aspect, a method for preparing a light emitting diode is provided, the method comprising:

[0015] fabricating an epitaxial structure on the reflective layer;

[0016] Making a current spreading layer on the epitaxial structure;

[0017] A first electrode is manufactured on the current spreading layer, wherein a groove structure is provided on a side of the first electrode away from the current spreading layer, wherein a depth of the groove structure is less than 35% of a thickness of the first electrode, and an area of ​​the groove structure is less than 20% of an area of ​​a side of the first electrode away from the current spreading layer.

[0018] Optionally, manufacturing a first electrode on the current spreading layer includes:

[0019] Making an electrode body on the current spreading layer by metal evaporation;

[0020] A groove structure is formed on the electrode body by wet etching or ICP etching to obtain the first electrode.

[0021] Optionally, the method further comprises:

[0022] The surface of the epitaxial structure is patterned to form a current blocking groove, the current spreading layer covers the current blocking groove, and the first electrode is correspondingly arranged in the current blocking groove.

[0023] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:

[0024] In the disclosed embodiment, a groove structure is provided on the side of the first electrode away from the current expansion layer. The groove structure can increase the contact surface of the electrode welding part, making the electrode more firm during welding and reducing the risk of falling off; the groove structure can increase the pressure sharing area of ​​the electrode and reduce the overall volume of the electrode, that is, the deformation amount is reduced, thereby reducing the shading area caused by deformation and improving the brightness of the light-emitting diode. At the same time, the area ratio and depth ratio of the groove structure are limited to avoid the situation where the groove structure area is too large or the depth is too deep, resulting in low mechanical strength of the electrode and abnormal deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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.

[0026] Figure 1 is a structural schematic diagram of a light emitting diode provided by an embodiment of the present disclosure;

[0027] Figure 2 is a top view of the structure of a light emitting diode provided by an embodiment of the present disclosure;

[0028] Figure 3 is a schematic diagram of the relationship between the depth of the groove structure and the probability of abnormal occurrence provided by the embodiment of the present disclosure;

[0029] Figure 4 is a schematic diagram of the relationship between the area of ​​the groove structure and the probability of abnormal occurrence when the depth of the groove structure provided by the embodiment of the present disclosure accounts for 30%;

[0030] Figure 5 This is a brightness comparison diagram of a light-emitting diode in the related art when the groove structure provided by the embodiment of the present disclosure has a depth accounting for 30% and an area accounting for 15%;

[0031] Figure 6 is a flow chart of a method for preparing a light emitting diode provided by an embodiment of the present disclosure;

[0032] Figure 7 is a flow chart of another method for preparing a light emitting diode provided by an embodiment of the present disclosure;

[0033] Figure 8 is a structural schematic diagram of a light emitting diode manufacturing process provided by an embodiment of the present disclosure;

[0034] Fig. 9 is a structural schematic diagram of a light emitting diode manufacturing process provided by an embodiment of the present disclosure;

[0035] Fig.10 is a schematic diagram of a photoresist mask on the surface of an electrode body of a light-emitting diode provided by an embodiment of the present disclosure;

[0036] Fig.11 It is a cross-sectional schematic diagram of the groove structure of the first electrode of the light-emitting diode provided in an embodiment of the present disclosure.

[0037] The reference numerals are as follows:

[0038] 101: reflective layer; 102: epitaxial structure; 103: current spreading layer; 104: first electrode; 105: second electrode; 106: substrate; 201: N-type carrier confinement layer; 202: N-type current spreading layer; 203: P-type current spreading layer; 204: P-type carrier confinement layer; 205: P-type window layer; 301: first semiconductor layer; 302: active layer; 303: second semiconductor layer; 1041: groove structure; 1042: strip groove; 1021: current blocking groove. DETAILED DESCRIPTION

[0039] 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.

[0040] 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 comprises: a reflective layer 101, an epitaxial structure 102, a current spreading layer 103 and a first electrode 104. The epitaxial structure 102 and the current spreading layer 103 are sequentially stacked on the reflective layer 101, and the first electrode 104 is located on the current spreading layer 103.

[0041] Figure 2 is a top view of the structure of a light emitting diode provided by an embodiment of the present disclosure. Figure 2 A groove structure 1041 is provided on a side of the first electrode 104 away from the current spreading layer 103, the depth of the groove structure 1041 is less than 35% of the thickness of the first electrode 104, and the area of ​​the groove structure 1041 is less than 20% of the area of ​​the side of the first electrode 104 away from the current spreading layer 103.

[0042] In the disclosed embodiment, a groove structure is provided on the side of the first electrode away from the current expansion layer. The groove structure can increase the contact surface of the electrode welding part, making the electrode more firm during welding and reducing the risk of falling off; the groove structure can increase the pressure sharing area of ​​the electrode and reduce the overall volume of the electrode, that is, the deformation amount is reduced, thereby reducing the shading area caused by deformation and improving the brightness of the light-emitting diode. At the same time, the area ratio and depth ratio of the groove structure are limited to avoid the situation where the groove structure area is too large or the depth is too deep, resulting in low mechanical strength of the electrode and abnormal deformation.

[0043] In the embodiment of the present disclosure, the reflective layer 101 may be a distributed Bragg reflector (DBR) layer. The DBR layer may be SiO 2 With Ti 3 O 5 The formed stack.

[0044] In the embodiment of the present disclosure, the epitaxial structure 102 may include a first semiconductor layer 301 , an active layer 302 , and a second semiconductor layer 303 that are sequentially stacked.

[0045] In the embodiment of the present disclosure, the first semiconductor layer 301 includes an N-type carrier confinement layer 201 and an N-type current spreading layer 202 which are stacked in sequence.

[0046] In the embodiment of the present disclosure, the N-type carrier confinement layer 201 may be an N-type AlInP carrier confinement layer, and the N-type current spreading layer 202 may be an N-type AlGaInP current spreading layer.

[0047] In the embodiment of the present disclosure, the active layer 302 is a multi-quantum well layer, including a plurality of periodically alternately stacked AlGaInP quantum well layers and AlGaInP quantum barrier layers.

[0048] In the embodiment of the present disclosure, the second semiconductor layer 303 includes a P-type current spreading layer 203 , a P-type carrier confinement layer 204 and a P-type window layer 205 .

[0049] In the disclosed embodiment, the P-type current spreading layer 203 may be a P-type AlGaInP current spreading layer, the P-type carrier confinement layer 204 may be a P-type AlInP carrier confinement layer, and the P-type window layer 205 may be a P-type GaP window layer.

[0050] In the disclosed embodiment, the current spreading layer 103 may be an indium tin oxide (ITO) layer. ITO has good transparency and conductivity and can conduct current to form an electrical connection while allowing light to pass through.

[0051] In a possible implementation of the present disclosure, the first electrode 104 may be an Al electrode.

[0052] In another possible implementation of the present disclosure, the first electrode 104 may also be an AlCu electrode. Compared with Al, AlCu has a higher hardness and is less prone to deformation.

[0053] In the disclosed embodiment, the depth of the groove structure 1041 is 20-30% of the thickness of the first electrode 104. On the one hand, the above depth can prevent the groove from being too shallow, resulting in too small a stress sharing area; on the other hand, the above depth can prevent the groove from being too deep, resulting in poor mechanical strength of the electrode, which affects the yield of the light-emitting diode.

[0054] Exemplarily, the depth of the groove structure 1041 is 25% of the thickness of the first electrode 104 .

[0055] Figure 3Schematic diagram of the relationship between the depth of the groove structure and the probability of abnormal occurrence provided by the embodiment of the present disclosure. Figure 3 The horizontal axis is the ratio of the groove depth to the electrode thickness (that is, the depth ratio of the groove structure). The vertical axis is the probability of abnormal occurrence of the electrode. Figure 3 It can be seen that when the groove depth accounts for less than 35% of the electrode thickness, the probability of electrode abnormality is the lowest, and when the proportion is higher than 35%, the probability of electrode abnormality gradually increases. This shows that setting the groove structure depth to less than 35% of the electrode thickness can avoid electrode abnormality and thus affect the yield of the light-emitting diode.

[0056] In the disclosed embodiment, the area of ​​the groove structure 1041 is 10-15% of the area of ​​the side of the first electrode 104 away from the current spreading layer 103. On the one hand, the above area can avoid the groove being too small, resulting in too small stress sharing area; on the other hand, the above area can avoid the groove area being too large, resulting in poor mechanical strength, which affects the yield of the light-emitting diode.

[0057] Exemplarily, the area of ​​the groove structure 1041 is 15% of the area of ​​a side of the first electrode 104 away from the current spreading layer 103 .

[0058] Figure 4 3 is a schematic diagram showing the relationship between the area of ​​the groove structure and the probability of abnormal occurrence when the depth of the groove structure provided by the embodiment of the present disclosure accounts for 30%. Figure 4 The horizontal axis is the ratio of the groove area to the electrode surface area (that is, the area ratio of the groove structure). The vertical axis is the probability of abnormal occurrence of the electrode. Figure 4 It can be seen that when the groove area accounts for less than 20% of the electrode surface area, the probability of electrode abnormality is the lowest, and when the proportion is higher than 20%, the probability of electrode abnormality gradually increases. This shows that setting the area of ​​the groove structure to less than 20% of the electrode area can avoid electrode abnormality and thus affect the yield of the light-emitting diode.

[0059] Table 1 below is a comparison of brightness data of a light emitting diode in the related art when the groove structure provided by the embodiment of the present disclosure has a depth of 30% and an area of ​​15%.

[0060] Wherein, LOP is the light output performance, the unit is MCD; AVG is the mean value.

[0061] Figure 5 This is a comparison chart of the brightness of the light-emitting diode provided by the embodiment of the present disclosure when the depth of the groove structure accounts for 30% and the area accounts for 15% with that of the light-emitting diode of the related technology. The horizontal axis is LOP, and the unit is MCD. The vertical axis is the ratio of the number of various brightnesses to the total number of tested pieces. Figure 5 The lines connected by the central points represent the related art, and the lines connected by the triangles represent the embodiments of the present disclosure.

[0062] Based on Table 1 and Figure 5 It can be seen from the data that by using the electrode structure provided in the embodiment of the present disclosure, the average light emission of the light-emitting diode is brightened by 7%, and the normal distribution trend is that the overall brightness is improved.

[0063] Table 1

[0064]

[0065] See again Figure 2 The groove structure 1041 includes a plurality of strip-shaped grooves 1042 extending from the middle to the edge of the first electrode 104. The strip-shaped groove structure can make the pressure distribution of the electrode more uniform.

[0066] In a possible implementation of the present disclosure, the cross-section of the strip groove 1042 is an inverted trapezoid, which can increase the contact surface of the electrode welding part, make the electrode more secure during welding, and reduce the risk of falling off.

[0067] Exemplarily, the bottom angle of the inverted trapezoid can be set as needed, such as 120 to 150 degrees.

[0068] In other possible implementations of the present disclosure, the cross-section of the strip-shaped groove 1042 may also be other shapes, such as a rectangle, an arc, etc.

[0069] In other embodiments of the present disclosure, the groove structure 1041 may also include strip grooves in other combinations, or be composed of grooves of other shapes, which is not limited to this.

[0070] like Figure 1 and Figure 2 As shown, a current blocking groove 1021 is opened on the surface of the epitaxial structure 102, the current spreading layer 103 covers the current blocking groove 1021, and the first electrode 104 is correspondingly arranged in the current blocking groove 1021, which can make the current diffusion more uniform and improve the LED yield.

[0071] like Figure 2 As shown, the current blocking groove 1021 may be rectangular. In other embodiments, the current blocking groove 1021 may also be circular or other shapes.

[0072] like Figure 1 and Figure 2 As shown, the first electrode 104 may be in a truncated cone shape. In other embodiments, the first electrode 104 may also be in a cylindrical shape or other shapes.

[0073] like Figure 1 As shown, the light emitting diode may further include a substrate 106 , and the reflective layer 101 is located on the substrate 106 .

[0074] By way of example, the substrate 106 may be a GaAs substrate.

[0075] like Figure 1 As shown, the light emitting diode may further include a second electrode 105 , and the second electrode 105 is located on a side of the substrate 106 away from the reflective layer 101 .

[0076] Exemplarily, the second electrode 105 may be a TiAu electrode or an Au / AuGeNi / Au / Pt / Au electrode.

[0077] In the embodiment of the present disclosure, the first electrode 104 may be a P electrode, and the second electrode 105 may be an N electrode.

[0078] Figure 6 is a flow chart of a method for preparing a light emitting diode provided by an embodiment of the present disclosure. Figure 6 The method steps include:

[0079] S11. Fabricating an epitaxial structure on the reflective layer.

[0080] In the embodiment of the present disclosure, the epitaxial structure may include a first semiconductor layer, an active layer, and a second semiconductor layer stacked in sequence.

[0081] In the embodiment of the present disclosure, the first semiconductor layer includes an N-type carrier confinement layer and an N-type current spreading layer stacked in sequence.

[0082] Exemplarily, a Metal Organic Chemical Vapor Deposition (MOCVD) device is used to sequentially form an N-type carrier confinement layer and an N-type current spreading layer on the surface of the substrate.

[0083] In the embodiment of the present disclosure, the N-type carrier confinement layer may be an N-type AlInP carrier confinement layer, and the N-type current spreading layer may be an N-type AlGaInP current spreading layer.

[0084] In the embodiment of the present disclosure, the growth of the semiconductor layer can be achieved by using Veeco K465i or C4 or RB MOCVD equipment or AIXTRON metal organic chemical vapor deposition equipment. 2 (Hydrogen) or high purity N 2 (nitrogen) or high purity H 2 and high purity N 2 A mixed gas of high purity NH 3 As the N source, trimethylgallium (TMGa) and triethylgallium (TEGa) as the gallium source, trimethylindium (TMIn) as the indium source, silane (SiH 4) as N-type dopant, trimethylaluminum (TMAl) as aluminum source, bis(cyclopentadienyl)magnesium (CP 2 Mg) as a P-type dopant.

[0085] In the embodiment of the present disclosure, the active layer is a multi-quantum well layer, including a plurality of periodically alternately stacked AlGaInP quantum well layers and AlGaInP quantum barrier layers.

[0086] Exemplarily, a plurality of AlGaInP quantum well layers and AlGaInP quantum barrier layers are alternately grown on the surface of the first semiconductor layer using MOCVD equipment.

[0087] In the embodiment of the present disclosure, the second semiconductor layer includes a P-type current spreading layer, a P-type carrier confinement layer and a P-type window layer.

[0088] In the embodiment of the present disclosure, the P-type current spreading layer may be a P-type AlGaInP current spreading layer, the P-type carrier confinement layer may be a P-type AlInP carrier confinement layer, and the P-type window layer may be a P-type GaP window layer.

[0089] Exemplarily, a P-type AlGaInP current spreading layer, a P-type AlInP carrier confinement layer and a P-type GaP window layer are sequentially fabricated on the surface of the active layer using MOCVD equipment.

[0090] S12, manufacturing a current spreading layer on the epitaxial structure.

[0091] S13. A first electrode is manufactured on the current spreading layer, wherein a groove structure is provided on a side of the first electrode away from the current spreading layer, wherein a depth of the groove structure is less than 35% of a thickness of the first electrode, and an area of ​​the groove structure is less than 20% of an area of ​​a side of the first electrode away from the current spreading layer.

[0092] In the disclosed embodiment, a groove structure is provided on the side of the first electrode away from the current expansion layer. The groove structure can increase the contact surface of the electrode welding part, making the electrode more firm during welding and reducing the risk of falling off; the groove structure can increase the pressure sharing area of ​​the electrode and reduce the overall volume of the electrode, that is, the deformation amount is reduced, thereby reducing the shading area caused by deformation and improving the brightness of the light-emitting diode. At the same time, the area ratio and depth ratio of the groove structure are limited to avoid the situation where the groove structure area is too large or the depth is too deep, resulting in low mechanical strength of the electrode and abnormal deformation.

[0093] Figure 7 is a flow chart of another method for preparing a light emitting diode provided by an embodiment of the present disclosure. Figure 7 The method steps include:

[0094] S21. Making a reflective layer on a substrate.

[0095] In the embodiment of the present disclosure, the substrate may be a GaAs substrate.

[0096] In the embodiment of the present disclosure, the reflective layer may be a DBR layer.

[0097] For example, the DBR layer may include a plurality of periodically alternately stacked Ti 3 O 5 Layer and SiO 2 layer.

[0098] S22, sequentially forming a first semiconductor layer, an active layer, and a second semiconductor layer on the reflective layer.

[0099] Figure 8 Schematic diagram of the structure of the light emitting diode manufacturing process provided by the embodiment of the present disclosure. Figure 8 , a first semiconductor layer 301 , an active layer 302 and a second semiconductor layer 303 are sequentially grown on the reflective layer 101 .

[0100] Exemplarily, step S22 may include:

[0101] The first step is to make the first semiconductor layer.

[0102] In the embodiment of the present disclosure, the first semiconductor layer includes an N-type AlGaInP current spreading layer and an N-type AlInP carrier confinement layer stacked in sequence.

[0103] Exemplarily, an N-type AlGaInP current spreading layer and an N-type AlInP carrier confinement layer are sequentially fabricated on the reflective layer using MOCVD equipment.

[0104] In the embodiment of the present disclosure, the growth of the semiconductor layer can be achieved by using Veeco K465i or C4 or RB MOCVD equipment or AIXTRON metal organic chemical vapor deposition equipment. 2 (Hydrogen) or high purity N 2 (nitrogen) or high purity H 2 and high purity N 2 A mixed gas of high purity NH 3 As the N source, trimethylgallium (TMGa) and triethylgallium (TEGa) as the gallium source, trimethylindium (TMIn) as the indium source, silane (SiH 4 ) as N-type dopant, trimethylaluminum (TMAl) as aluminum source, bis(cyclopentadienyl)magnesium (CP 2 Mg) as a P-type dopant.

[0105] The second step is to make the active layer.

[0106] In the embodiment of the present disclosure, the active layer is a multi-quantum well layer, including a plurality of periodically alternately stacked AlGaInP quantum well layers and AlGaInP quantum barrier layers.

[0107] Exemplarily, a plurality of AlGaInP quantum well layers and AlGaInP quantum barrier layers are alternately grown on the surface of the first semiconductor layer using MOCVD equipment.

[0108] The third step is to make the second semiconductor layer.

[0109] In the embodiment of the present disclosure, the second semiconductor layer includes a P-type AlGaInP current spreading layer, a P-type AlInP carrier confinement layer and a P-type GaP window layer.

[0110] Exemplarily, a P-type AlGaInP current spreading layer, a P-type AlInP carrier confinement layer and a P-type GaP window layer are sequentially fabricated on the surface of the active layer using MOCVD equipment.

[0111] S23, performing patterning on the surface of the epitaxial structure to form a current blocking groove.

[0112] Fig. 9 Schematic diagram of the structure of the light emitting diode manufacturing process provided by the embodiment of the present disclosure. Fig. 9 , the current blocking groove 1021 is opened on the second semiconductor layer 303 .

[0113] In the embodiment of the present disclosure, step S23 may include:

[0114] The surface of the epitaxial structure is patterned to form a current blocking groove.

[0115] Exemplarily, this step may include: first forming a photoresist mask on the surface of the epitaxial structure, then etching the epitaxial structure using inductively coupled plasma (ICP), and then removing the photoresist mask using a stripping solution.

[0116] In the embodiment of the present disclosure, etching the surface of the epitaxial structure refers to etching the P-type GaP window layer.

[0117] S24, manufacturing a current spreading layer, wherein the current spreading layer covers the current blocking groove.

[0118] In the embodiment of the present disclosure, the current spreading layer may be an ITO layer. ITO has excellent transparency and conductivity and can conduct current to form an electrical connection while allowing light to pass through.

[0119] In the disclosed embodiment, the current spreading layer is evaporated on the entire surface by metal evaporation equipment.

[0120] S25. Making an electrode body on the current spreading layer.

[0121] In the disclosed embodiment, the electrode body is manufactured on the current spreading layer by metal evaporation.

[0122] In a possible implementation of the present disclosure, the first electrode may be an Al electrode.

[0123] In another possible implementation of the present disclosure, the first electrode may also be an AlCu electrode. AlCu has good stability and is not easily deformed.

[0124] S26, opening a groove structure on the electrode body to obtain a first electrode.

[0125] In the disclosed embodiment, a groove structure is formed on the electrode body by wet etching or ICP etching to obtain the first electrode. The groove structure can increase the pressure sharing area of ​​the electrode and reduce the overall volume of the electrode, that is, reduce the deformation, thereby reducing the shading area caused by deformation and improving the brightness of the light-emitting diode.

[0126] Exemplarily, step S26 may include:

[0127] The first step is to make a photoresist mask on the surface of the electrode body.

[0128] Fig.10 Schematic diagram of a photoresist mask on the surface of an electrode body of a light-emitting diode provided by an embodiment of the present disclosure, such as Fig.10 As shown, the shaded portion is a photoresist mask.

[0129] In the second step, the electrode body is etched using a photoresist mask as a shield.

[0130] The third step is to remove the photoresist using a stripping solution.

[0131] like Figure 2 As shown, the groove structure 1041 includes a plurality of strip-shaped grooves 1042 extending from the middle to the edge of the first electrode 104 . The strip-shaped groove structure can make the pressure distribution of the electrode more uniform.

[0132] In the embodiment of the present disclosure, the cross-section of the strip groove 1042 is an inverted trapezoid, which can increase the contact surface of the electrode welding part, make the electrode more secure during welding, and reduce the risk of falling off.

[0133] Fig.11 FIG. 1 is a cross-sectional schematic diagram of a groove structure of a first electrode of a light-emitting diode provided in an embodiment of the present disclosure. Fig.11 As shown, the cross section of the strip-shaped groove in the groove structure is an inverted trapezoid.

[0134] Of course, the cross-section of the strip-shaped groove in the groove structure may also be other shapes, and the present disclosure does not limit this.

[0135] In the disclosed embodiment, the depth of the groove structure 1041 is 20-30% of the thickness of the first electrode 104. On the one hand, the above depth can prevent the groove from being too shallow, resulting in too small a stress sharing area; on the other hand, the above depth can prevent the groove from being too deep, resulting in poor mechanical strength of the electrode, which affects the yield of the light-emitting diode.

[0136] Exemplarily, the depth of the groove structure 1041 is 25% of the thickness of the first electrode 104 .

[0137] In the disclosed embodiment, the area of ​​the groove structure 1041 is 10-15% of the area of ​​the side of the first electrode 104 away from the current spreading layer 103. On the one hand, the above area can avoid the groove being too small, resulting in too small stress sharing area; on the other hand, the above area can avoid the groove area being too large, resulting in poor mechanical strength, which affects the yield of the light-emitting diode.

[0138] Exemplarily, the area of ​​the groove structure 1041 is 15% of the area of ​​a side of the first electrode 104 away from the current spreading layer 103 .

[0139] S27. Fabricate a second electrode on a side of the substrate away from the epitaxial structure.

[0140] In the embodiment of the present disclosure, the second electrode may be a TiAu electrode or an Au / AuGeNi / Au / Pt / Au electrode.

[0141] In the embodiment of the present disclosure, the second electrode is evaporated by metal evaporation equipment.

[0142] In the disclosed embodiment, the chip thickness can be reduced by grinding before evaporating the second electrode.

[0143] 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: a reflective layer (101), an epitaxial structure (102), a current spreading layer (103) and a first electrode (104); the epitaxial structure (102) and the current spreading layer (103) are sequentially stacked on the reflective layer (101); and the first electrode (104) is located on the current spreading layer (103); A groove structure (1041) is provided on a side of the first electrode (104) away from the current spreading layer (103), the depth of the groove structure (1041) is less than 35% of the thickness of the first electrode (104), and the area of ​​the groove structure (1041) is less than 20% of the area of ​​the side of the first electrode (104) away from the current spreading layer (103).

2. The light emitting diode according to claim 1, characterized in that: The depth of the groove structure (1041) is 20-30% of the thickness of the first electrode (104).

3. The light emitting diode according to claim 1 or 2, characterized in that: The area of ​​the groove structure (1041) is 10-15% of the area of ​​a side of the first electrode (104) away from the current spreading layer (103).

4. The light emitting diode according to claim 1 or 2, characterized in that: The groove structure (1041) comprises a plurality of strip-shaped grooves (1042) extending from the middle to the edge of the first electrode (104).

5. The light emitting diode according to claim 4, characterized in that: The cross section of the strip-shaped groove (1042) is an inverted trapezoid.

6. The light emitting diode according to claim 1 or 2, characterized in that: The first electrode (104) is an AlCu alloy electrode.

7. The light emitting diode according to claim 1 or 2, characterized in that: A current blocking groove (1021) is provided on the surface of the epitaxial structure (102), the current expansion layer (103) covers the current blocking groove (1021), and the first electrode (104) is correspondingly arranged in the current blocking groove (1021).

8. A method for preparing a light emitting diode, characterized in that: The light emitting diode preparation method comprises: fabricating an epitaxial structure on the reflective layer; Making a current spreading layer on the epitaxial structure; A first electrode is manufactured on the current spreading layer, wherein a groove structure is provided on a side of the first electrode away from the current spreading layer, wherein a depth of the groove structure is less than 35% of a thickness of the first electrode, and an area of ​​the groove structure is less than 20% of an area of ​​a side of the first electrode away from the current spreading layer.

9. The method for preparing a light emitting diode according to claim 8, characterized in that: Producing a first electrode on the current spreading layer, comprising: Making an electrode body on the current spreading layer by metal evaporation; A groove structure is formed on the electrode body by wet etching or ICP etching to obtain the first electrode.

10. The method for preparing a light emitting diode according to claim 8 or 9, characterized in that: The method further comprises: The surface of the epitaxial structure is patterned to form a current blocking groove, the current spreading layer covers the current blocking groove, and the first electrode is correspondingly arranged in the current blocking groove.

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