Light emitting diode and method of manufacturing the same

Abstract

The present disclosure provides a light emitting diode and a preparation method thereof. The light emitting diode comprises an epitaxial structure, a composite transparent conductive layer, a dielectric film layer and a metal reflective layer; the composite transparent conductive layer comprises a first transparent conductive sublayer and a second transparent conductive sublayer, and the second transparent conductive sublayer comprises a plurality of conductive units; the first transparent conductive sublayer is located on the surface of the epitaxial structure, the plurality of conductive units are arranged on the surface of the first transparent conductive sublayer at intervals, the dielectric film layer covers the first transparent conductive sublayer, the dielectric film layer has through holes corresponding to the plurality of conductive units, the bottom of the through holes is located on the surface of the conductive units, and the metal reflective layer covers the dielectric film layer and is electrically connected with the second transparent conductive sublayer in the through holes. The composite transparent conductive layer comprises the first transparent conductive sublayer and the second transparent conductive sublayer, which avoids over-etching when making the through holes of the dielectric film layer, makes the transparent conductive layer too thin, causes the current spreading ability to decrease, and improves the reliability of the light emitting diode.

Description

Technical Field

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

[0002] A light-emitting diode (LED) is a semiconductor device that emits light.

[0003] The related technology provides a light-emitting diode (LED) whose structure includes an epitaxial structure, a transparent conductive layer, a dielectric film layer, and a metal reflective layer. The transparent conductive layer is located on the epitaxial structure, the dielectric film layer is located on the transparent conductive layer, and through-holes are formed in the dielectric film layer by etching. The metal reflective layer is connected to the transparent conductive layer through the through-holes.

[0004] In related technologies, when creating openings in the dielectric film layer, over-etching can easily occur, damaging the transparent conductive layer and making it too thin. An excessively thin transparent conductive layer will lead to a decrease in current spreading capability and a reduction in the reliability of the light-emitting diode. Summary of the Invention

[0005] This disclosure provides a light-emitting diode and its fabrication method, which can significantly improve the problem of over-etching during the etching of vias in the dielectric film layer. Simultaneously, the one-time etching increases the effective reflective area of ​​the second insulating reflective sublayer, thereby improving reflectivity. The technical solution is as follows:

[0006] On one hand, a light-emitting diode is provided, the light-emitting diode comprising: an epitaxial structure, a composite transparent conductive layer, a dielectric film layer, and a metal reflective layer;

[0007] The composite transparent conductive layer includes a first transparent conductive sublayer and a second transparent conductive sublayer, wherein the second transparent conductive sublayer includes a plurality of conductive units;

[0008] The first transparent conductive sublayer is located on the surface of the epitaxial structure, the plurality of conductive units are arranged at intervals on the surface of the first transparent conductive sublayer, the dielectric film layer covers the first transparent conductive sublayer, the dielectric film layer has through holes corresponding to the plurality of conductive units, the bottom of the through holes is located on the surface of the conductive units, and the metal reflective layer covers the dielectric film layer and is electrically connected to the second transparent conductive sublayer in the through holes.

[0009] Optionally, the thickness of the first transparent conductive layer is 70 to 300 angstroms, and the thickness of the second transparent conductive layer is 50 to 200 angstroms.

[0010] Optionally, the projections of the conductive unit and the through hole onto the surface of the epitaxial structure are two concentric circles, and the projected area of ​​the conductive unit is larger than the projected area of ​​the through hole.

[0011] Optionally, the dielectric film layer includes a first insulating reflective sublayer and a second insulating reflective sublayer stacked sequentially;

[0012] Both the first insulating reflective sublayer and the second insulating reflective sublayer have the through-hole.

[0013] Optionally, the first insulating reflective sublayer is a SiO2 layer, and the second insulating reflective sublayer is a DBR layer, wherein the DBR layer is a stack of alternating SiO2 and Ti3O5 layers.

[0014] Optionally, the alternation period of SiO2 and Ti3O5 in the second insulating reflective sublayer is 5 to 13 cycles.

[0015] Optionally, the sidewall of the through-hole in the dielectric film is a slope.

[0016] Optionally, the width H of the through hole opening is 30–80 μm. 2 .

[0017] On the other hand, a method for fabricating a light-emitting diode is provided, the method comprising:

[0018] Fabrication of epitaxial structures;

[0019] A composite transparent conductive layer is fabricated on the surface of the epitaxial structure. The composite transparent conductive layer includes a first transparent conductive sublayer and a second transparent conductive sublayer. The second transparent conductive sublayer includes a plurality of conductive units. The first transparent conductive sublayer is located on the surface of the epitaxial structure. The plurality of conductive units are arranged at intervals on the surface of the first transparent conductive sublayer.

[0020] A dielectric film layer is fabricated on the composite transparent conductive layer, the dielectric film layer covering the first transparent conductive sublayer, the dielectric film layer having through holes corresponding to the plurality of conductive units, and the bottom of the through holes being located on the surface of the conductive unit;

[0021] A metal reflective layer is fabricated, which covers the dielectric film layer and is electrically connected to the second transparent conductive layer within the through-hole.

[0022] Optionally, a composite transparent conductive layer is formed on the surface of the epitaxial structure, comprising:

[0023] A first transparent conductive film is fabricated on the surface of the epitaxial structure to obtain the first transparent conductive sublayer;

[0024] A second transparent conductive film is fabricated on the surface of the first transparent conductive sublayer;

[0025] The second transparent conductive film is patterned to obtain the plurality of conductive units as the second transparent conductive sublayer.

[0026] Optionally, the dielectric film layer includes a first insulating reflective sublayer and a second insulating reflective sublayer stacked sequentially;

[0027] Fabricating a dielectric film layer on the composite transparent conductive layer includes:

[0028] The first insulating reflective sublayer is fabricated using a PECVD device. The first insulating reflective sublayer is a SiO2 layer.

[0029] The second insulating reflective sublayer is fabricated using an optical coating machine. The second insulating reflective sublayer is a DBR layer, which is a stack of alternating SiO2 and Ti3O5 layers.

[0030] The through-hole is fabricated on the first insulating reflective sublayer and the second insulating reflective sublayer using a patterning process.

[0031] Optionally, the second insulating reflective sublayer is fabricated using an optical coating machine, comprising:

[0032] SiO2 and Ti3O5 layers are alternately fabricated using an optical coating machine, with an alternation cycle of 5 to 13 cycles.

[0033] The beneficial effects of the technical solutions provided in this disclosure are:

[0034] In this embodiment, the light-emitting diode employs a composite transparent conductive layer, which includes a first transparent conductive sublayer and a second transparent conductive sublayer. The second transparent conductive sublayer includes multiple conductive units, which are spaced apart on the surface of the first transparent conductive sublayer. A dielectric film layer has vias corresponding to the conductive units, with the bottom of each via located on the surface of a conductive unit. This structural design ensures that when creating vias in the dielectric film layer, even if over-etching occurs, the etching is only applied to the conductive units and does not affect the first transparent conductive sublayer. This avoids the problem of over-etching during the fabrication of vias in the dielectric film layer, which can lead to an excessively thin transparent conductive layer and reduced current spreading capability, thus improving the reliability of the light-emitting diode. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of a light-emitting diode provided in an embodiment of this disclosure;

[0037] Figure 2 This is a flowchart of a method for fabricating a light-emitting diode provided in an embodiment of this disclosure;

[0038] Figure 3 This is a flowchart of another method for fabricating a light-emitting diode provided in this embodiment.

[0039] The attached figures are labeled as follows:

[0040] 10: Epitaxial structure; 20: Electrode structure; 30: Insulating structure;

[0041] 101: Substrate; 102: First semiconductor layer; 103: Active layer; 104: Second semiconductor layer; 105: Composite transparent conductive layer; 106: Dielectric film layer; 107: Metal reflective layer; 108: First electrode; 109: First electrode pad; 110: First insulating layer; 111: Second insulating layer; 112: Second electrode; 113: Second electrode pad; 114: Through-hole in the first insulating layer; 115: Through-hole in the second insulating layer; 116: Isolation trench; 117: Stepped structure; 118: Through-hole;

[0042] 1051: First transparent conductive sublayer; 1052: Second transparent conductive sublayer; 1053: Conductive unit;

[0043] 1061: First insulating reflective sublayer; 1062: Second insulating reflective sublayer;

[0044] H: Width of the opening. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0046] Figure 1 This is a schematic diagram of the structure of a light-emitting diode provided in an embodiment of this disclosure. See also... Figure 1 The light-emitting diode includes: an epitaxial structure 10, a composite transparent conductive layer 105, a dielectric film layer 106, and a metal reflective layer 107.

[0047] The composite transparent conductive layer 105 includes a first transparent conductive sublayer 1051 and a second transparent conductive sublayer 1052, and the second transparent conductive sublayer 1052 includes a plurality of conductive units 1053.

[0048] The first transparent conductive sublayer 1051 is located on the surface of the epitaxial structure 10. A plurality of conductive units 1053 are spaced apart on the surface of the first transparent conductive sublayer 1051. The dielectric film layer 106 covers the first transparent conductive sublayer 1051. The dielectric film layer 106 has through holes 118 corresponding to the plurality of conductive units 1053. The bottom of the through holes 118 is located on the surface of the conductive units 1053. The metal reflective layer 107 covers the dielectric film layer 106 and is electrically connected to the second transparent conductive sublayer 1052 in the through holes 118.

[0049] In this embodiment, the light-emitting diode employs a composite transparent conductive layer, which includes a first transparent conductive sublayer and a second transparent conductive sublayer. The second transparent conductive sublayer includes multiple conductive units, which are spaced apart on the surface of the first transparent conductive sublayer. A dielectric film layer has vias corresponding to the conductive units, with the bottom of each via located on the surface of a conductive unit. This structural design ensures that when creating vias in the dielectric film layer, even if over-etching occurs, the etching is only applied to the conductive units and does not affect the first transparent conductive sublayer. This avoids the problem of over-etching during the fabrication of vias in the dielectric film layer, which can lead to an excessively thin transparent conductive layer and reduced current spreading capability, thus improving the reliability of the light-emitting diode.

[0050] In this embodiment of the disclosure, the first transparent conductive sublayer 1051 and the second transparent conductive sublayer 1052 can be indium tin oxide (ITO) layers. ITO has good transparency and conductivity, which allows light to pass through while also conducting current to form an electrical connection.

[0051] In this embodiment, the thickness of the first transparent conductive electronic layer 1051 can be 70 to 300 angstroms. This thickness will not cause the ohmic contact and current spread of the second semiconductor layer to deteriorate due to being too thin, nor will it cause the film layer to absorb light and reduce the light extraction efficiency due to being too thick.

[0052] For example, the thickness of the first transparent conductive electronic layer 1051 is 200 angstroms.

[0053] In this embodiment, the thickness of the second transparent conductive layer 1052 can be 50 to 200 angstroms. This thickness is such that if it is too thin, the etching barrier capability of the second transparent conductive layer will decrease, resulting in over-etching; and if it is too thick, the overall thickness of the light-emitting diode will be too large.

[0054] For example, the thickness of the second transparent conductive electronic layer 1052 is 100 angstroms.

[0055] In this embodiment, the projections of the conductive unit 1053 and the via 118 onto the surface of the epitaxial structure 10 are two concentric circles, with the projected area of ​​the conductive unit 1053 being larger than that of the via 118. This design ensures the etching blocking effect of the conductive unit, prevents over-etching, and results in more uniform etching of the via.

[0056] The conductive unit 1053 and the through hole 118 can be frustum-shaped, wherein the cross-section of the conductive unit 1053 is trapezoidal, and the cross-section of the through hole 118 is an inverted trapezoid. The projected area can be such that the projected area of ​​the top of the conductive unit 1053 is greater than the projected area of ​​the bottom of the through hole 118, or the projected area of ​​the bottom of the conductive unit 1053 is greater than the projected area of ​​the top of the through hole 118, or the projected area of ​​the middle part of the conductive unit 1053 is greater than the projected area of ​​the middle part of the through hole 118.

[0057] In other embodiments, the projections of the conductive unit 1053 and the through-hole 118 onto the surface of the epitaxial structure 10 can also be other shapes, such as rectangles.

[0058] In this embodiment of the disclosure, the dielectric film layer 106 includes a first insulating reflective sublayer 1061 and a second insulating reflective sublayer 1062 stacked sequentially.

[0059] Both the first insulating reflective sublayer 1061 and the second insulating reflective sublayer 1062 have the through hole 118.

[0060] In the embodiments of this disclosure, the dielectric film layer formed by stacking the first insulating reflective sublayer and the second insulating reflective sublayer can increase the reflective effect of the reflective layer and improve the brightness of the light-emitting diode.

[0061] In this embodiment, the sidewalls of the through-holes 118 in the dielectric film layer 106 are sloped. The slope can increase the effective reflective area of ​​the second insulating reflective sublayer, thereby improving the reflectivity.

[0062] In this embodiment, the width H of the through hole 118 can be 30–80 μm. 2 The opening area is sufficient to ensure electrical contact between the metal and the reflective effect.

[0063] For example, the width H of the opening of the through hole 118 is 50 μm. 2 .

[0064] In this embodiment, the first insulating reflective sublayer 1061 can be a SiO2 layer. The SiO2 layer has good stability and provides growth conditions for the second insulating reflective sublayer.

[0065] In this embodiment, the thickness of the first insulating reflective sublayer 1061 can be 4000–6000 angstroms. This thickness is neither too thin, which would lead to over-etching and damage to the underlying structure, nor too thick, which would result in an excessively thick overall light-emitting diode.

[0066] For example, the thickness of the first insulating reflective sublayer 1061 is 5500 angstroms.

[0067] In this embodiment, the second insulating reflective sublayer 1062 can be a DBR layer, which is a stack of alternating SiO2 and Ti3O5 layers. The DBR layer has good reflectivity, improving the brightness of the light-emitting diode.

[0068] In this embodiment, the alternation period of SiO2 and Ti3O5 in the second insulating reflective sublayer 1062 can be 5 to 13 cycles. This number of cycles is neither too few, which would lead to a decrease in reflectivity, nor too many, which would result in an excessively thick overall light-emitting diode.

[0069] For example, the alternation period of SiO2 and Ti3O5 in the second insulating reflective sublayer 1062 can be 8 periods.

[0070] In this embodiment, the thickness of the second insulating reflective sublayer 1062 can be 2000–6000 angstroms. This thickness is neither too thin, which would reduce the reflective area after etching and decrease reflection, nor too thick, which would make the overall light-emitting diode too thick.

[0071] For example, the thickness of the second insulating reflective sublayer 1062 is 3700 angstroms.

[0072] In this embodiment of the disclosure, the light-emitting diode may further include: a substrate 101, an electrode structure 20, and an insulating structure 30.

[0073] For example, the epitaxial structure 10 includes a first semiconductor layer 102, an active layer 103, and a second semiconductor layer 104.

[0074] For example, the electrode structure 20 includes a first electrode 108, a first electrode pad 109, a second electrode 112, and a second electrode pad 113.

[0075] For example, the insulating structure 30 includes a first insulating layer 110 and a second insulating layer 111.

[0076] 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 have a stepped structure 117 extending to the first semiconductor layer 102. The stepped structure 117 has a bottom surface and a top surface. The bottom surface of the stepped structure is located on the first semiconductor layer 102, and the top surface of the stepped structure is located on the second semiconductor layer 104. The bottom of the isolation trench 116 is located on the substrate 101.

[0077] The first insulating layer 110 covers the metal reflective layer 107 and the dielectric film layer 106. The first insulating layer 110 has through holes 114 at the metal reflective layer 107 and the stepped structure 117, respectively. The first electrode 108 is connected to the metal reflective layer 107 through the through holes 114 at the metal reflective layer 107. The second electrode 112 is connected to the epitaxial structure 10 (first semiconductor layer 102) through the through holes 114 at the stepped structure 117.

[0078] The second insulating layer 111 covers the second electrode 112 and the first insulating layer 110. The second insulating layer 111 has through holes 115 at the first electrode 108 and the second electrode 112 respectively. The first electrode pad 109 is connected to the first electrode 108 through the through hole 115 at the first electrode 108. The second electrode pad 113 is connected to the second electrode 112 through the through hole 115 at the second electrode 112.

[0079] In this embodiment of the disclosure, the substrate 101 can be any one of a sapphire patterned substrate, a Si substrate, or a SiC substrate, and the material of the substrate 101 is not limited in this embodiment of the disclosure.

[0080] For example, substrate 101 is a patterned sapphire substrate.

[0081] In this embodiment of the disclosure, the first semiconductor layer 102 can be an N-type semiconductor layer, and the second semiconductor layer 104 can be a P-type semiconductor layer.

[0082] For example, the first semiconductor layer 102 can be an N-type GaN material, and the second semiconductor layer 104 can be a P-type GaN material.

[0083] 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.

[0084] In this embodiment of the disclosure, the active layer 103 can be a multi-quantum well layer, for example, the multi-quantum well layer can be an InGaN / GaN multi-quantum well structure.

[0085] In this embodiment, the metal reflective layer 107 is a silver mirror layer, and the metal reflective layer 107 can be a combination of one or more metal or alloy layers such as Ag, Ni, Ti, TiW, Al, AlCu, Ti, Ni, Pt, and Au. Among them, metal Ag is the main structure, which plays the role of light reflection and current spread, while Ni and TiW play the role of preventing the migration and diffusion of metal Ag.

[0086] For example, the metal reflective layer 107 is a stack of Ag, Ni, Ti and TiW.

[0087] In this embodiment of the disclosure, the first electrode 108 and the second electrode 112 can be a combination of one or more metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt and Au.

[0088] For example, the first electrode 108 and the second electrode 112 are Cr, Al, AlCu, Ti, Ni, Pt and Au stacks.

[0089] In this embodiment of the disclosure, the first electrode pad 109 and the second electrode pad 113 can be a combination of one or more metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt, Au and AuSn.

[0090] For example, the first electrode pad 109 and the second electrode pad 113 are Cr, Al, AlCu, Ti, Ni, Pt, Au and AuSn stacks.

[0091] In this embodiment of the disclosure, the first insulating layer 110 and the second insulating layer 111 can be a distributed Bragg reflector (DBR) layer or a SiO2 layer, wherein the DBR layer is a stack formed of SiO2 and Ti3O5.

[0092] It is worth noting that, in the embodiments of this disclosure, the structure can be selectively added or reduced based on the structure of the light-emitting diode described above, and this disclosure does not limit this.

[0093] Figure 2 This is a flowchart illustrating a method for fabricating a light-emitting diode (LED) according to an embodiment of this disclosure. See also... Figure 2 The method includes the following steps:

[0094] S11. Fabricate the extensional structure.

[0095] S12. A composite transparent conductive layer is fabricated on the surface of the epitaxial structure. The composite transparent conductive layer includes a first transparent conductive sublayer and a second transparent conductive sublayer. The second transparent conductive sublayer includes a plurality of conductive units. The first transparent conductive sublayer is located on the surface of the epitaxial structure, and the plurality of conductive units are arranged at intervals on the surface of the first transparent conductive sublayer.

[0096] S13. A dielectric film layer is formed on the composite transparent conductive layer, the dielectric film layer covering the first transparent conductive sublayer, the dielectric film layer having through holes corresponding to the plurality of conductive units, and the bottom of the through holes being located on the surface of the conductive unit.

[0097] S14. Fabricate a metal reflective layer, which covers the dielectric film layer and is electrically connected to the second transparent conductive layer in the through hole.

[0098] In this embodiment, the light-emitting diode employs a composite transparent conductive layer, which includes a first transparent conductive sublayer and a second transparent conductive sublayer. The second transparent conductive sublayer includes multiple conductive units, which are spaced apart on the surface of the first transparent conductive sublayer. A dielectric film layer has vias corresponding to the conductive units, with the bottom of each via located on the surface of a conductive unit. This structural design ensures that when creating vias in the dielectric film layer, even if over-etching occurs, the etching is only applied to the conductive units and does not affect the first transparent conductive sublayer. This avoids the problem of over-etching during the fabrication of vias in the dielectric film layer, which can lead to an excessively thin transparent conductive layer and reduced current spreading capability, thus improving the reliability of the light-emitting diode.

[0099] Figure 3 This is a flowchart of another method for fabricating a light-emitting diode provided in this disclosure. See also... Figure 3 The method includes the following steps:

[0100] S21. A first semiconductor layer, an active layer, and a second semiconductor layer are sequentially formed on a substrate, and the second semiconductor layer, the active layer, and the first semiconductor layer constitute an epitaxial structure.

[0101] The substrate can be any one of the following: a patterned sapphire substrate, a Si substrate, or a SiC substrate.

[0102] In one example, step S21 includes:

[0103] The first step is to fabricate the first semiconductor layer.

[0104] In this embodiment of the disclosure, the first semiconductor layer is N-type GaN.

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

[0106] In this embodiment of the disclosure, the active layer is a multi-quantum well layer, for example, the multi-quantum well layer can be an InGaN / GaN multi-quantum well structure.

[0107] The third step is to fabricate the second semiconductor layer.

[0108] In this embodiment of the disclosure, the second semiconductor layer is a P-type GaN.

[0109] In this embodiment of the present disclosure, a first semiconductor layer, an active layer, and a second semiconductor layer are sequentially stacked on a substrate.

[0110] S22. The epitaxial structure is patterned to form a stepped structure. The stepped structure has a top surface and a bottom surface. The bottom surface of the stepped structure is located inside the epitaxial structure, the top surface of the stepped structure is located in the second semiconductor layer, and the bottom of the isolation trench is located on the substrate.

[0111] In this embodiment of the disclosure, the epitaxial structure is patterned by inductively coupled plasma (ICP) etching.

[0112] S23. A transparent conductive layer is composited on the surface of the epitaxial structure, the composite transparent conductive layer including a first transparent conductive sublayer and a second transparent conductive sublayer.

[0113] In one example, step S23 includes:

[0114] The first step is to fabricate a first transparent conductive film on the surface of the epitaxial structure to obtain a first transparent conductive sublayer.

[0115] In this embodiment, the first transparent conductive layer can be an indium tin oxide (ITO) layer. ITO has excellent transparency and conductivity, allowing light to pass through while also conducting current to form an electrical connection.

[0116] In this embodiment, the thickness of the first transparent conductive electronic layer can be 70 to 300 angstroms. This thickness is such that if it is too thin, the ohmic contact and current spread of the second semiconductor layer will deteriorate, and if it is too thick, the film layer will absorb light and reduce the light extraction efficiency.

[0117] For example, the thickness of the first transparent conductive electronic layer is 200 angstroms.

[0118] The second step is to fabricate a second transparent conductive film on the surface of the first transparent conductive layer.

[0119] In this embodiment, the second transparent conductive layer can be an ITO layer. ITO has excellent transparency and conductivity, allowing light to pass through while also conducting current to form an electrical connection.

[0120] In this embodiment, the thickness of the second transparent conductive layer can be 50 to 200 angstroms. This thickness is such that if it is too thin, the etching barrier capability of the second transparent conductive layer will decrease, resulting in over-etching; and if it is too thick, the overall thickness of the light-emitting diode will be too large.

[0121] For example, the thickness of the second transparent conductive electronic layer is 100 angstroms.

[0122] The third step is to pattern the second transparent conductive film to obtain multiple conductive units as the second transparent conductive sublayer.

[0123] In this embodiment, the projections of the conductive unit and the via on the epitaxial structure surface are two concentric circles, with the projected area of ​​the conductive unit being larger than that of the via. This design ensures the etching blocking effect of the conductive unit, prevents over-etching, and results in more uniform etching of the via.

[0124] In other embodiments, the projections of the conductive cells and vias onto the surface of the epitaxial structure can also be other shapes, such as rectangles.

[0125] S24. A dielectric film layer is fabricated on the composite transparent conductive layer. The dielectric film layer passes through the second transparent conductive sublayer and is connected to the first transparent conductive sublayer. The dielectric film layer includes a first insulating reflective sublayer and a second insulating reflective sublayer.

[0126] In this embodiment of the disclosure, a first insulating reflective sublayer and a second insulating reflective sublayer are fabricated using plasma-enhanced chemical vapor deposition (PECVD).

[0127] In this embodiment of the disclosure, the first insulating reflective sublayer may be a SiO2 layer.

[0128] In this embodiment, the thickness of the first insulating reflective sublayer can be 4000–6000 angstroms. This thickness is neither too thin, which would lead to over-etching and damage to the underlying structure, nor too thick, which would result in an excessively thick overall light-emitting diode.

[0129] For example, the thickness of the first insulating reflective sublayer is 5500 angstroms.

[0130] In this embodiment, a second insulating reflective layer is fabricated using an optical coating machine. This second insulating reflective layer can be a DBR layer, which is a stack of alternating SiO2 and Ti3O5 layers. The DBR layer has good reflectivity, improving the brightness of the light-emitting diode.

[0131] In this embodiment, an optical coating machine is used to alternately fabricate SiO2 and Ti3O5 layers, with an alternation period of 5 to 13 cycles. This number of cycles is such that too few cycles will result in a decrease in reflectivity, while too many cycles will result in an excessively thick overall LED.

[0132] For example, an optical coating machine is used to alternately fabricate SiO2 and Ti3O5 layers, with an alternation period of up to 8 cycles.

[0133] In this embodiment, the thickness of the second insulating reflective sublayer can be 2000–6000 angstroms. This thickness is such that it is neither too thin, which would reduce the reflective area after etching and thus decrease reflection, nor too thick, which would make the overall light-emitting diode too thick.

[0134] For example, the thickness of the second dielectric film sublayer is 3700 angstroms.

[0135] S25. The through-hole is fabricated on the first insulating reflective sublayer and the second insulating reflective sublayer using a patterning process.

[0136] In this embodiment of the disclosure, vias in the dielectric film reflective layer are fabricated by ICP etching, and the vias are fabricated on the first insulating reflective sublayer and the second insulating reflective sublayer using a patterning process.

[0137] In this embodiment, a single patterning process is used, and the through-hole has only one slope. This reduces the size of the upper part of the through-hole while keeping the lower part size unchanged, thereby increasing the effective area of ​​the dielectric film reflective layer, improving reflectivity, and increasing the brightness of the LED chip.

[0138] In this embodiment, the sidewalls of the vias in the dielectric film layer are sloped. The slope can increase the effective reflective area of ​​the second insulating reflective sublayer, thereby improving the reflectivity.

[0139] In this embodiment, the width of the through-hole opening can be 30–80 μm. 2 The opening area is sufficient to ensure electrical contact between the metal and the reflective effect.

[0140] For example, the width of the through-hole opening is 50 μm. 2 .

[0141] S26. Fabricate an insulating structure and an electrode structure. The insulating structure is covered with a metal reflective layer and a dielectric film layer. The electrode structure passes through the insulating structure and is connected to the epitaxial structure.

[0142] In one example, step S26 includes:

[0143] The first step is to create the first insulating layer, which covers the metal reflective layer and the dielectric film layer.

[0144] The first insulating layer can be a DBR layer or a SiO2 layer, where the DBR layer is a stack of SiO2 and Ti3O5.

[0145] The second step is to perform graphic processing on the first insulating layer and open through holes in the first insulating layer at the stepped structure.

[0146] In this embodiment of the disclosure, the first insulating layer via is formed by wet etching or dry etching.

[0147] The third step is to fabricate the first electrode and the second electrode. The first electrode is connected to the metal reflective layer through a through-hole in the first insulating layer at the metal reflective layer, and the second electrode is connected to the epitaxial structure through a through-hole in the first insulating layer at the stepped structure.

[0148] In the embodiments of this disclosure, the first electrode and the second electrode can be a combination of one or more metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt and Au.

[0149] For example, the first electrode and the second electrode are a stack of Cr, Al, AlCu, Ti, Ni, Pt and Au.

[0150] The fourth step is to create a second insulating layer, which covers the first electrode, the second electrode, and the first insulating layer.

[0151] The second insulating layer can be a DBR layer or a SiO2 layer, where the DBR layer is a stack of SiO2 and Ti3O5.

[0152] The fifth step involves patterning the first and second insulating layers, creating through-holes in the first insulating layer at the metal reflective layer and the stepped structure, and creating through-holes in the second insulating layer at the first and second electrodes.

[0153] In this embodiment of the disclosure, the first insulating layer via and the second insulating layer via are formed by wet etching or dry etching.

[0154] For example, the wet etching process for creating through holes in the first and second insulating layers is relatively simple, low-cost, and has good isotropy, allowing for uniform through-hole formation.

[0155] Step 6: Fabricate the first electrode pad and the second electrode pad. The first electrode pad is connected to the first electrode through a through-hole in the second insulating layer at the first electrode, and the second electrode pad is connected to the second electrode through a through-hole in the second insulating layer at the second electrode.

[0156] In this embodiment of the disclosure, the first electrode pad and the second electrode pad can be a combination of one or more metal or alloy layers such as Cr, Al, AlCu, Ti, Ni, Pt, Au and AuSn.

[0157] For example, the first electrode pad and the second electrode pad are Cr, Al, AlCu, Ti, Ni, Pt, Au and AuSn stacks.

[0158] Table 1 compares the brightness of light-emitting diodes (LEDs) fabricated using related technologies and embodiments of this disclosure. Taking a 55mil chip as an example, the number of vias in the light-emitting region is 1014, and the top area of ​​a single via in an LED fabricated using related technologies is 201µm. 2 The top area of ​​a single through-hole fabricated using the embodiments of this disclosure is 50 μm. 2 The area of ​​the composite dielectric film layer increases by approximately 9%. Performance comparisons were conducted using chips fabricated from epitaxial wafers from the same furnace batch. Compared to related technical solutions, the technical solution provided in this disclosure shows an average brightness increase of 1.81%, while other parameters are comparable.

[0159] Table 1

[0160]

[0161]

[0162] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A light emitting diode, characterized by, The light-emitting diode includes: an epitaxial structure (10), a composite transparent conductive layer (105), a dielectric film layer (106), and a metal reflective layer (107); The composite transparent conductive layer (105) includes a first transparent conductive sublayer (1051) and a second transparent conductive sublayer (1052), wherein the second transparent conductive sublayer (1052) includes a plurality of conductive units (1053); The first transparent conductive sublayer (1051) is located on the surface of the epitaxial structure (10), the plurality of conductive units (1053) are spaced apart on the surface of the first transparent conductive sublayer (1051), the dielectric film layer (106) covers the first transparent conductive sublayer (1051), the dielectric film layer (106) has a through hole (118) corresponding to the plurality of conductive units (1053), the bottom of the through hole (118) is located on the surface of the conductive unit (1053), and the metal reflective layer (107) covers the dielectric film layer (106) and is electrically connected to the second transparent conductive sublayer (1052) in the through hole (118).

2. The light emitting diode of claim 1, wherein, The thickness of the first transparent conductive sublayer (1051) is 70 to 300 angstroms, and the thickness of the second transparent conductive sublayer (1052) is 50 to 200 angstroms.

3. The light emitting diode according to claim 1 or 2, characterized in that The projections of the conductive unit (1053) and the through hole (118) on the surface of the epitaxial structure (10) are two concentric circles, and the projected area of ​​the conductive unit (1053) is larger than the projected area of ​​the through hole (118).

4. The light emitting diode according to claim 1 or 2, wherein The dielectric film layer (106) includes a first insulating reflective sublayer (1061) and a second insulating reflective sublayer (1062) stacked sequentially; Both the first insulating reflective sublayer (1061) and the second insulating reflective sublayer (1062) have the through hole (118).

5. The light emitting diode of claim 4, wherein, The first insulating reflective sublayer (1061) is a SiO2 layer, and the second insulating reflective sublayer (1062) is a DBR layer, wherein the DBR layer is a stack of alternating SiO2 and Ti3O5 layers.

6. The light emitting diode of claim 5, wherein, The alternation period of SiO2 and Ti3O5 in the second insulating reflective sublayer (1062) is 5 to 13 cycles.

7. The light-emitting diode according to claim 1 or 2, characterized in that, The sidewall of the through hole (118) of the dielectric film layer (106) is a slope.

8. The light-emitting diode according to claim 7, characterized in that, The width H of the opening of the through hole (118) is 30 to 80 μm 2 .

9. A method for fabricating a light-emitting diode, characterized in that, The method includes: Fabrication of epitaxial structures; A composite transparent conductive layer is fabricated on the surface of the epitaxial structure. The composite transparent conductive layer includes a first transparent conductive sublayer and a second transparent conductive sublayer. The second transparent conductive sublayer includes a plurality of conductive units. The first transparent conductive sublayer is located on the surface of the epitaxial structure. The plurality of conductive units are arranged at intervals on the surface of the first transparent conductive sublayer. A dielectric film layer is fabricated on the composite transparent conductive layer, the dielectric film layer covering the first transparent conductive sublayer, the dielectric film layer having through holes corresponding to the plurality of conductive units, and the bottom of the through holes being located on the surface of the conductive unit; A metal reflective layer is fabricated, which covers the dielectric film layer and is electrically connected to the second transparent conductive layer within the through-hole.

10. The method for fabricating a light-emitting diode according to claim 9, characterized in that, A composite transparent conductive layer is fabricated on the surface of the epitaxial structure, including: A first transparent conductive film is fabricated on the surface of the epitaxial structure to obtain the first transparent conductive sublayer; A second transparent conductive film is fabricated on the surface of the first transparent conductive sublayer; The second transparent conductive film is patterned to obtain the plurality of conductive units as the second transparent conductive sublayer.

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