Light-emitting diode structure

Abstract

The present disclosure provides a light-emitting diode structure, including a substrate, a first semiconductor layer, a light-emitting layer, a second semiconductor layer, a semiconductor contact layer, a first conductive layer, and a second conductive layer. The first semiconductor layer is disposed on the substrate and has a first thickness structure and a second thickness structure, and a first thickness of the first thickness structure is greater than a second thickness of the second thickness structure. The light-emitting layer is disposed on the first thickness structure. The second semiconductor layer is disposed on the light-emitting layer, and a doping type of the second semiconductor layer is different from that of the first semiconductor layer. The semiconductor contact layer is disposed on the second thickness structure, and a vertical projection of the semiconductor contact layer and the light-emitting layer on the substrate does not overlap or contact, and a doping type of the semiconductor contact layer is the same as that of the first semiconductor layer. The present disclosure reduces the forward operating voltage and component waste heat, and improves the output power and component reliability.

Description

Technical Field

[0001] The present disclosure relates to a light emitting diode structure, and more particularly to a light emitting diode structure capable of lowering forward operation voltage and reducing waste heat of a device. Background Art

[0002] Light Emitting Diode (LED) is a light-emitting element made of semiconductor materials that can convert electrical energy into light. It has the advantages of small size, high energy conversion efficiency, long life, and power saving. Therefore, it is widely used as a light source for various electronic devices.

[0003] In the structural design of UV LED, in order to reduce the light absorption effect of semiconductors, N-type aluminum gallium nitride is usually used as the N-type contact layer. However, compared with the N-type gallium nitride commonly used in blue light, the contact resistance of N-type aluminum gallium nitride is higher, which will make the operating voltage of the component higher. The second problem is that when the aluminum composition is higher than 20%, a higher alloy temperature is required, but this will reduce the reflectivity of the N-type metal, which is not conducive to the luminous efficiency of the component.

[0004] In the prior art, in order to solve the above problems, an N-type contact layer with an aluminum content lower than that of the N-type layer is added between the N-type layer and the light-emitting layer in the process. However, when the aluminum content of the N-type contact layer approaches that of the N-type layer, the voltage reduction effect is not good. When the aluminum content of the N-type contact layer is much smaller than that of the N-type layer or even approaches 0, although the voltage can be improved, it may produce a light absorption effect, and because the lattice matching difference becomes larger, the quality of the epitaxial layer subsequently formed on the N-type contact layer is degraded, thereby affecting the light-emitting efficiency.

[0005] Another known method for reducing the contact resistance of the N-type electrode is to increase the electron concentration of the N-type contact layer between the N-type layer and the light-emitting layer by high doping. In practice, the concentration of doped silicon is increased to 1x10 19 / cm 3 However, if the doping concentration is too high, it will be detrimental to the crystal quality of the subsequent light-emitting layer quantum well growth.

[0006] In the above growth method, the thickness of the N-type contact layer must be at least greater than 0.5 μm because of the tolerance of the etching process. This deteriorates the quality of the quantum well epitaxy formed on the N-type contact layer, which is not conducive to the light-emitting efficiency. In view of this, the existing technology needs to be improved. Summary of the invention

[0007] The purpose of the present disclosure is to provide a light emitting diode structure to achieve the effect of lowering the forward operating voltage, reducing the waste heat of the device, and improving the output power and reliability.

[0008] The present disclosure provides a light-emitting diode structure, including a substrate, a first semiconductor layer, at least one light-emitting layer, at least one second semiconductor layer, at least one semiconductor contact layer, at least one first conductive layer, and at least one second conductive layer. The first semiconductor layer is disposed on the substrate and has at least one first thickness structure and at least one second thickness structure, and the first thickness of at least one first thickness structure is greater than the second thickness of at least one second thickness structure. At least one light-emitting layer is disposed on at least one first thickness structure of the first semiconductor layer. At least one second semiconductor layer is disposed on at least one light-emitting layer, and the doping type of at least one second semiconductor layer is different from that of the first semiconductor layer. At least one semiconductor contact layer is disposed on at least one second thickness structure of the first semiconductor layer, the vertical projections of at least one semiconductor contact layer and at least one light-emitting layer on the substrate do not overlap or contact, and the doping type of at least one semiconductor contact layer is the same as that of the first semiconductor layer. At least one first conductive layer is disposed on at least one semiconductor contact layer. At least one second conductive layer is disposed on at least one second semiconductor layer.

[0009] In some embodiments, the light-emitting diode structure further includes an insulating layer, at least one first conductive pad, and at least one second conductive pad. The insulating layer covers at least the sidewalls of at least one first thickness structure, the upper surface of at least one second thickness structure, the sidewalls of at least one light-emitting layer, the sidewalls of at least one second semiconductor layer, the sidewalls and the upper surface of at least one semiconductor contact layer, the sidewalls of at least one first conductive layer, and the sidewalls and the upper surface of at least one second conductive layer. The insulating layer further has at least one first opening and at least one second opening respectively located above at least one first conductive layer and at least one second conductive layer. At least one first conductive pad and at least one second conductive pad are disposed on the insulating layer and are electrically connected to at least one first conductive layer and at least one second conductive layer respectively through at least one first opening and at least one second opening.

[0010] In some embodiments, at least one semiconductor contact layer includes Al x Ga y In 1-x-y N, where 0 ≤ x, y ≤ 1.

[0011] In some embodiments, when x + y = 1, the doping concentration of at least one semiconductor contact layer is greater than 1 x 10 19 / cm 3 .

[0012] In some embodiments, the thickness of at least one semiconductor contact layer is between about 1 nm and about 500 nm.

[0013] In some embodiments, the doping concentration of at least one semiconductor contact layer is higher than that of the first semiconductor layer.

[0014] In some embodiments, at least one semiconductor contact layer includes a plurality of sub-contact layers, and the doping concentration of each sub-contact layer may be the same or different, and the sub-contact layers may be stacked in sequence according to the doping concentration from high to low or at least two doping concentrations may be stacked alternately.

[0015] In some embodiments, at least one semiconductor contact layer includes a plurality of sub-contact layers, and these sub-contact layers include Al x Ga y In 1-x-y N, where 0≤x,y≤1. Among them, when x + y = 1 for each sub-contact layer, the doping concentration of the sub-contact layer adjacent to at least one first conductive layer is greater than that of other sub-contact layers.

[0016] In some embodiments, at least one semiconductor contact layer includes a plurality of sub-contact layers, and these sub-contact layers include Al x Ga y In 1-x-y N, where 0≤x,y≤1. Among them, the sub-contact layer adjacent to at least one first conductive layer is Ga y In 1-y N, where 0 < y < 1.

[0017] In some embodiments, at least one semiconductor contact layer includes a plurality of sub-contact layers, and the sub-contact layers may be stacked in sequence according to the energy gap from high to low or at least two energy gaps may be stacked alternately.

[0018] In some embodiments, at least one semiconductor contact layer includes a plurality of independent contact layers, and these independent contact layers are all electrically connected to the first semiconductor layer and at least one first conductive layer, and each two adjacent independent contact layers are spaced apart from each other by an insulating portion.

[0019] In some embodiments, when the number of semiconductor contact layers is multiple, a light-emitting layer is included between any two adjacent semiconductor contact layers, and when the number of first conductive layers is multiple, these first conductive layers are respectively disposed on these semiconductor contact layers.

[0020] In some embodiments, the light-emitting diode structure further includes a conductive connection layer, which is disposed on these first conductive layers and configured to electrically connect each first conductive layer.

[0021] In some embodiments, the semiconductor contact layer includes a plurality of through holes, and these through holes penetrate the semiconductor contact layer along the thickness direction.

[0022] The present disclosure provides a light-emitting diode structure, including a substrate, a second conductive layer, a second semiconductor layer, a light-emitting layer, a first semiconductor layer, a first conductive layer, an insulating layer, and a semiconductor contact layer. The second conductive layer is disposed on the substrate. The second semiconductor layer is disposed on the second conductive layer. The light-emitting layer is disposed on the second semiconductor layer. The first semiconductor layer is disposed on the light-emitting layer, and the doping type of the first semiconductor layer is different from that of the second semiconductor layer. The first conductive layer is disposed between the substrate and the second conductive layer, and the first conductive layer includes a base portion and a protruding portion. The protruding portion penetrates through the second conductive layer, the second semiconductor layer, and the light-emitting layer to be electrically connected to the first semiconductor layer. The insulating layer is disposed between the first conductive layer and the second conductive layer. The semiconductor contact layer is disposed between the protruding portion of the first conductive layer and the first semiconductor layer, and the doping type of the semiconductor contact layer is the same as that of the first semiconductor layer. Wherein, the protruding portion of the first conductive layer and the semiconductor contact layer are both electrically isolated from the second conductive layer, the second semiconductor layer, and the light-emitting layer through the extending portion of the insulating layer.

[0023] In some embodiments, the doping concentration of the semiconductor contact layer is higher than that of the first semiconductor layer.

[0024] In some embodiments, the semiconductor contact layer includes a plurality of sub-contact layers. The doping concentration of each sub-contact layer can be the same or different, and the arrangement of each sub-contact layer can be stacked in sequence according to the doping concentration from high to low or alternately stacked with at least two doping concentrations.

[0025] In some embodiments, the semiconductor contact layer includes a plurality of independent contact layers. These independent contact layers are all electrically connected to the first semiconductor layer and the first conductive layer, and each two adjacent independent contact layers are spaced from each other through an insulating portion.

[0026] In some embodiments, the semiconductor contact layer includes a plurality of through holes, and these through holes penetrate through the semiconductor contact layer along the thickness direction. Description of the Drawings

[0027] The following will be read in conjunction with the drawings. The various aspects of the present disclosure can be best understood according to the following detailed description. It should be understood that, according to the convention in the industry, the various features are not drawn to scale. In fact, for clarity, the dimensions of the various features can be increased or decreased arbitrarily.

[0028] Figure 1 To show a top view of the light-emitting diode structure according to some embodiments of the present disclosure;

[0029] Figure 2 To show according to Figure 1 The cross-sectional schematic diagram of the cross-section line AA' in

[0030] Figures 3 to 8Schematic cross-sectional views showing the manufacturing of a light-emitting diode structure according to some embodiments of the present disclosure at various steps;

[0031] Figure 9 Schematic cross-sectional views showing a light-emitting diode structure according to some other embodiments of the present disclosure;

[0032] Figure 10 Schematic cross-sectional views showing a light-emitting diode structure according to still some other embodiments of the present disclosure;

[0033] Figure 11 Top view showing a light-emitting diode structure according to some embodiments of the present disclosure;

[0034] Figure 12 For showing according to Figure 11 Schematic cross-sectional view along the section line BB' in;

[0035] Figure 13 Top view showing a light-emitting diode structure according to some other embodiments of the present disclosure;

[0036] Figure 14 For showing according to Figure 13 Schematic cross-sectional view along the section line CC' in;

[0037] Figure 15 Top view showing a light-emitting diode structure according to still some other embodiments of the present disclosure;

[0038] Figure 16 For showing according to Figure 15 Schematic cross-sectional view along the section line DD' in;

[0039] Figure 17 Top view showing a light-emitting diode structure according to still some other embodiments of the present disclosure;

[0040] Figure 18 For showing according to Figure 17 Schematic cross-sectional view along the section line EE' in;

[0041] Figure 19 Top view showing a light-emitting diode structure according to still some other embodiments of the present disclosure;

[0042] Figure 20 For showing according to Figure 19 Schematic cross-sectional view along the section line FF' in;

[0043] Figure 21 Schematic cross-sectional views showing a light-emitting diode structure according to still some other embodiments of the present disclosure;

[0044] Figure 22Schematic diagram of a semiconductor contact layer in a light-emitting diode structure according to some further embodiments of the present disclosure.

[0045]

Symbol Description

[0046] 100: Light-emitting diode structure

[0047] 110: Substrate

[0048] 120: First semiconductor layer

[0049] 122: First thickness structure

[0050] 124: Second thickness structure

[0051] 126: Upper surface

[0052] 130: Light-emitting layer

[0053] 140: Second semiconductor layer

[0054] 150: Semiconductor contact layer

[0055] 150’: Semiconductor contact layer

[0056] 151 - 154: Sub-contact layers

[0057] 155: Independent contact layer

[0058] 156: Insulating portion

[0059] 157: Through hole

[0060] 160: First conductive layer

[0061] 160a: First conductive layer base

[0062] 160b: First conductive layer protrusion

[0063] 170: Second conductive layer

[0064] 172: Upper surface

[0065] 180: Insulating layer

[0066] 182: First opening

[0067] 184: Second opening

[0068] 186: Top surface

[0069] 180a: Insulating layer extension

[0070] 190a: First conductive pad

[0071] 190b: Second conductive pad

[0072] AA’: Section line

[0073] BB’: Section line

[0074] CC’: Section line

[0075] DD’: Section line

[0076] EE’: Section line

[0077] FF’: Section line

[0078] CL: Conductive connection layer

[0079] T1: First thickness

[0080] T2: Second thickness Detailed implementation manners

[0081] The following disclosure provides many different embodiments or examples for implementing different features of the provided subject matter. Specific examples of the following original elements, numerical values, operations, materials, configurations, and the like are used to simplify the disclosure. Of course, these are merely examples and are not intended to be limiting. Other original elements, numerical values, operations, materials, configurations, and the like also need to be considered. For example, in the following description, forming a first feature above a second feature may include embodiments in which the first feature and the second feature are formed in direct contact, and may also include embodiments in which additional features may be formed between the first feature and the second feature such that the first feature and the second feature are not in direct contact. Additionally, the disclosure may repeat reference numerals and / or words in various examples. This repetition itself does not indicate a relationship between the various embodiments and / or configurations discussed.

[0082] In addition, for ease of description, spatially relative terms such as "below", "beneath", "lower", "above", "upper", etc. may be used in the disclosure to describe one element or feature in relation to another or more elements or features as shown in the figures. In addition to the orientations described in the figures, the spatially relative terms are also intended to cover different orientations of the device during use or operation. The device may be oriented in other ways (rotated 90 degrees or in other directions), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0083] Generally, the light-emitting device of the present disclosure can be used in any related device with lighting or light-emitting functions. By growing a thin semiconductor contact layer (or ohmic contact layer) on the surface of the N-type semiconductor layer not covered by the light-emitting layer, an ohmic contact is formed for the N-type electrode, so as to reduce the forward operating voltage, reduce the alloy temperature and component waste heat, and improve the output power and component reliability, without affecting the epitaxial crystal quality of the light-emitting layer.

[0084] Example 1

[0085] In some embodiments of the present disclosure, a light-emitting diode structure 100 capable of reducing the forward operating voltage is provided. Please also refer to Figure 1 and Figure 2 , Figure 1 which is a top view showing the light-emitting diode structure according to some embodiments of the present disclosure. Figure 2 is a schematic cross-sectional view showing the cross-section along the hatching line AA' in Figure 1 . It should be noted that for convenience of reference, Figure 2 the insulating layer 180, the first conductive pad 190a and the second conductive pad 190b in Figure 1 are not shown in

[0086] In some embodiments of the present disclosure, as shown in Figure 2 , the first semiconductor layer 120 is disposed on the substrate 110. The first semiconductor layer 120 has a first thickness structure 122 and a second thickness structure 124, and the first thickness T1 of the first thickness structure 122 is greater than the second thickness T2 of the second thickness structure 124. The substrate 110 can include any suitable substrate. In one embodiment, the substrate 110 can be a transparent substrate or an opaque substrate. In some embodiments, the material of the substrate 110 includes, but is not limited to, a glass substrate, a sapphire substrate, a silicon substrate, a printed circuit board, a metal substrate, a ceramic substrate, an acrylic substrate, or a combination thereof. In one embodiment, the material of the substrate 110 includes, but is not limited to, silicon dioxide (SiO 2 ), silicon nitride (Si 3 N 4 ), titanium dioxide (TiO 2 ), tantalum pentoxide (Ta 2 O 5 ), gold, aluminum, copper, nickel, or a combination thereof.

[0087] In one embodiment, the first semiconductor layer 120 may be an N-type group III-V semiconductor layer. In some embodiments of the present disclosure, the group III-V semiconductor layer may include, but is not limited to, binary epitaxial materials such as gallium arsenide (GaAs), gallium nitride (GaN), gallium phosphide (GaP), indium arsenide (InAs), etc., or ternary or quaternary epitaxial materials such as gallium arsenide phosphide (GaAsP), aluminum gallium arsenide (AlGaAs), indium gallium phosphide (InGaP), indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN), aluminum indium gallium nitride (AlGaInN), aluminum indium gallium phosphide (AlInGaP), indium gallium arsenide phosphide (InGaAsP), etc. Therefore, the N-type group III-V semiconductor layer can be formed by doping the above group III-V semiconductor layer with group IV-A elements (such as silicon, etc.) or group VI-A elements (such as tellurium, etc.).

[0088] Please continue to refer to Figure 2 , in some embodiments, the light-emitting layer 130 is disposed on the first thickness structure 122 of the first semiconductor layer 120. In one embodiment, the light-emitting layer 130 may include, but is not limited to, multiple quantum wells (MQW), single quantum well (SQW), homojunction, heterojunction, or other similar structures.

[0089] Still please refer to Figure 2 , in some embodiments, the second semiconductor layer 140 is disposed on the light-emitting layer 130. In one embodiment, the second semiconductor layer 140 may be a P-type group III-V semiconductor layer. In some embodiments of the present disclosure, the group III-V semiconductor layer may include, but is not limited to, binary epitaxial materials such as gallium arsenide, gallium nitride, gallium phosphide, indium arsenide, aluminum nitride, indium nitride, indium phosphide, etc., or ternary or quaternary epitaxial materials such as gallium arsenide phosphide, aluminum gallium arsenide, indium gallium phosphide, indium gallium nitride, aluminum gallium nitride, aluminum indium gallium nitride, aluminum indium gallium phosphide, indium gallium arsenide phosphide, etc. Therefore, the P-type group III-V semiconductor layer can be formed by doping the above group III-V semiconductor layer with group II-A elements (such as beryllium, magnesium, calcium, or strontium, etc.) or group II-B elements (such as zinc, etc.). Therefore, the doping type of the second semiconductor layer 140 is different from that of the first semiconductor layer 120.

[0090] As Figure 2As shown, in some embodiments, the semiconductor contact layer 150 is disposed on the second thickness structure 124 of the first semiconductor layer 120, and the doping type of the semiconductor contact layer 150 is the same as that of the first semiconductor layer 120. By providing the semiconductor contact layer 150, the resistance between the first semiconductor layer 120 and the first conductive layer 160 can be reduced.

[0091] In one embodiment, the semiconductor contact layer 150 includes Al x Ga y In 1-x-y N, where 0 ≤ x, y ≤ 1. Specifically, the semiconductor contact layer 150 can be an N-type III-V semiconductor layer. In some embodiments of the present disclosure, the III-V semiconductor layer can include, but is not limited to, binary epitaxial materials such as gallium nitride, or ternary or quaternary epitaxial materials such as indium gallium nitride, aluminum gallium indium nitride, etc. Therefore, the N-type III-V semiconductor layer can be formed by doping the above III-V semiconductor layer with Group IV-A elements (such as silicon, etc.) or Group VI-A elements. As mentioned above, it should be noted that in some embodiments, the vertical projections of the semiconductor contact layer 150 and the light-emitting layer 130 on the substrate 110 do not overlap or contact, and the semiconductor contact layer 150 also does not overlap or contact the first thickness structure 122 of the first semiconductor layer 120. In one embodiment, the thickness of the semiconductor contact layer 150 is between about 1 nm and about 500 nm, including but not limited to 1 nm, 20 nm, 40 nm, 60 nm, 80 nm, 100 nm, 120 nm, 140 nm, 160 nm, 180 nm, 200 nm, 220 nm, 240 nm, 260 nm, 280 nm, 300 nm, 320 nm, 340 nm, 360 nm, 380 nm, 400 nm, 420 nm, 440 nm, 460 nm, 480 nm, 500 nm, or any value between any two of these values.

[0092] In some embodiments, the first conductive layer 160 is disposed on the semiconductor contact layer 150. In one embodiment of the present disclosure, the doping concentration of the semiconductor contact layer 150 is higher than that of the first semiconductor layer 120. In another embodiment of the present disclosure, the semiconductor contact layer 150 includes Al x Ga y In 1-x-y N, where x + y = 1, and the doping concentration of the semiconductor contact layer 150 is greater than 1 x 10 19 / cm 3 . Regarding the doping concentration of the above semiconductor contact layer 150, it is because when the doping concentration of the semiconductor contact layer 150 is greater than 1 x 10 19 / cm 3Only when the semiconductor contact layer 150 enters the degenerate state, the impurity energy levels form a continuous energy band, resulting in a reduction in the effective energy gap of the semiconductor contact layer 150, making it easier for carriers to be transported across the interfaces between the first semiconductor layer 120 and the semiconductor contact layer 150 and between the first conductive layer 160 and the semiconductor contact layer 150 (because the energy gap that the carriers need to cross is reduced), and thus the contact resistance decreases. In another embodiment of the present disclosure, the semiconductor contact layer 150 contains Al x Ga y In 1-x-y N, where x = 0, that is to say, the semiconductor contact layer 150 contains Ga y In 1-y N. At this time, the energy gap of the semiconductor contact layer 150 is lower, reducing the energy gap that carriers need to cross between the first semiconductor layer 120 and the first conductive layer 160, and thus the contact resistance decreases.

[0093] In some embodiments, the width of the first conductive layer 160 disposed on the semiconductor contact layer 150 is substantially smaller than that of the semiconductor contact layer 150. The material of the first conductive layer 160 includes, but is not limited to, a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), or a material with a transparent conductive effect; or an opaque metal material. For example, the opaque metal material includes chromium (Cr), gold (Au), titanium (Ti), aluminum (Al), vanadium (V), or a similar opaque metal material.

[0094] In some embodiments, the second conductive layer 170 is disposed on the second semiconductor layer 140, and the width of the second conductive layer 170 is substantially smaller than that of the second semiconductor layer 140. In one embodiment, the material of the second conductive layer 170 includes, but is not limited to, a transparent conductive material such as indium tin oxide, indium zinc oxide, aluminum zinc oxide, or a material with a transparent conductive effect; or an opaque metal material. For example, the opaque metal material includes gold, titanium, aluminum, nickel (Ni), platinum (Pt), palladium (Pd), or a similar opaque metal material.

[0095] Still refer to Figure 2, in one embodiment, an insulating layer 180 is disposed over the aforementioned light-emitting diode structure. The insulating layer 180 covers at least the sidewalls of the first thickness structure 122, the upper surface 126 of the second thickness structure 124, the sidewalls of the light-emitting layer 130, the sidewalls of the second semiconductor layer 140, the sidewalls and the upper surface of the semiconductor contact layer 150, the sidewalls and the upper surface of the first conductive layer 160, and the sidewalls and the upper surface 172 of the second conductive layer 170. In other embodiments, the insulating layer 180 may not cover the upper surface of the first conductive layer 160, meaning that the insulating layer 180 only covers the two sidewalls of the first conductive layer 160. Also, the insulating layer 180 has a first opening 182 and a second opening 184 located respectively over the first conductive layer 160 and the second conductive layer 170. In some embodiments of the present disclosure, the insulating layer 180 can be formed by chemical vapor deposition, printing, coating, or other suitable methods, and the first opening 182 and the second opening 184 can be formed by an etching process. In some embodiments, the materials used for the insulating layer 180 may include, but are not limited to, silicon oxide, silicon nitride, silicon oxynitride, epoxy resin, or other suitable insulating materials.

[0096] In one embodiment of the present disclosure, when the insulating layer 180 covers the sidewalls and the upper surface of the first conductive layer 160, the width of the first conductive layer 160 is substantially greater than the width of the first opening 182 of the insulating layer 180. In another embodiment, when the insulating layer 180 only covers the two sidewalls of the first conductive layer 160, the width of the first conductive layer 160 is substantially equal to the width of the first opening 182 of the insulating layer 180.

[0097] In one embodiment, a first conductive pad 190a is disposed over the insulating layer 180 and is electrically connected to the first conductive layer 160 through the first opening 182. A second conductive pad 190b is disposed over the insulating layer 180 and is electrically connected to the second conductive layer 170 through the second opening 184. Specifically, the first conductive pad 190a is disposed over the insulating layer 180 and fills the first opening 182; the second conductive pad 190b is disposed over the insulating layer 180 and fills the second opening 184. In some embodiments, the first conductive pad 190a and the second conductive pad 190b protrude and are exposed on the top surface 186 of the insulating layer 180, and the exposed portions can serve as platforms for electrical contact. In some embodiments, the materials of the first conductive pad 190a and the second conductive pad 190b include, but are not limited to, aluminum, copper, nickel, gold, platinum, titanium, or other suitable conductive materials.

[0098] Please refer to Figures 3 to 8 , Figures 3 to 8To illustrate cross-sectional schematic views of manufacturing a light-emitting diode structure at various steps according to some embodiments of the present disclosure, the manufacturing process of the light-emitting diode structure of the present disclosure will be described below. For the convenience of comparing the differences from the above embodiments and simplifying the description, the same symbols are used to label the same elements in the following embodiments, and the differences between the embodiments are mainly described, and the repeated parts will not be described again.

[0099] First, as Figure 3 shown, in one embodiment, the substrate 110 serves as a growth substrate for epitaxial growth. Then, the first semiconductor layer 120, the light-emitting layer 130, and the second semiconductor layer 140 are deposited or stacked in sequence from bottom to top. In some embodiments, the first semiconductor layer 120 is an N-type III-V semiconductor layer, and the second semiconductor layer 140 is a P-type III-V semiconductor layer. The formation or deposition methods of the foregoing first semiconductor layer 120, light-emitting layer 130, and second semiconductor layer 140 may include, but are not limited to, chemical vapor deposition, physical vapor deposition, plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition, electroplating, or other suitable processes and / or combinations thereof for deposition. In some embodiments, the sidewalls of the substrate 110, the first semiconductor layer 120, the light-emitting layer 130, and the second semiconductor layer 140 are flush with each other. Herein, the materials, materials, or compositions of the substrate 110, the first semiconductor layer 120, the light-emitting layer 130, and the second semiconductor layer 140 have been detailed in the previous paragraphs and will not be repeated here.

[0100] Next, as Figure 4 shown, in one embodiment, Figure 4A step of etching a part of the aforementioned second semiconductor layer 140, a part of the light-emitting layer 130, and a part of the first semiconductor layer 120, and exposing a part of the first semiconductor layer 120. In this step, a mask or an anti-etching material (not shown) is first disposed on the upper surface of a part of the second semiconductor layer 140, and etching is performed downward until a part of the first semiconductor layer 120 is also etched, and then the mask or the anti-etching material is removed. In this way, a first thickness structure 122 and a second thickness structure 124 of the first semiconductor layer 120 are formed. In an embodiment, the first thickness structure 122 has a first thickness T1, and the second thickness structure 124 has a second thickness T2. Also, the part of the first semiconductor layer 120 exposed after etching is the second thickness structure 124. Therefore, the aforementioned first thickness T1 is substantially greater than the second thickness T2. In this step, an etching process applicable to a large depth is included. In some embodiments, the etching process includes, but is not limited to, dry etching (such as plasma etching), wet etching (such as chemical etching), or other suitable processes and / or combinations thereof for etching. In an embodiment, the present disclosure uses plasma etching to expose the upper surface of the second thickness structure 124 of the first semiconductor layer 120.

[0101] As Figure 5 shown, in some embodiments, a semiconductor contact layer 150 is formed on the second thickness structure 124. In an embodiment, the width of the semiconductor contact layer 150 is substantially smaller than that of the second thickness structure 124, that is, a part of the upper surface of the second thickness structure 124 is still exposed after the semiconductor contact layer 150 is formed. In an embodiment, the formation method or deposition method of the semiconductor contact layer 150 may include, but is not limited to, chemical vapor deposition, physical vapor deposition, plasma-assisted chemical vapor deposition, atomic layer deposition, electroplating, or other suitable processes and / or combinations thereof for deposition. Herein, the material, material quality, or composition of the semiconductor contact layer 150 has been detailed in the previous paragraphs and will not be elaborated herein.

[0102] As Figure 6 shown, in some embodiments, after forming as Figure 5After the light-emitting diode structure shown, a first conductive layer 160 is formed on the semiconductor contact layer 150, and at the same time, a second conductive layer 170 is formed on the second semiconductor layer 140. The width of the first conductive layer 160 is substantially smaller than that of the semiconductor contact layer 150, and the width of the second conductive layer 170 is substantially smaller than that of the second semiconductor layer 140. That is to say, after the first conductive layer 160 and the second conductive layer 170 are formed, a part of the upper surfaces of the semiconductor contact layer 150 and the second semiconductor layer 140 is still exposed. In one embodiment, the method of forming or depositing the first conductive layer 160 includes, but is not limited to, chemical vapor deposition, physical vapor deposition, plasma-assisted chemical vapor deposition, atomic layer deposition, electroplating, or other suitable processes and / or combinations thereof for deposition. Herein, the materials, materials, or components of the first conductive layer 160 have been detailed in the previous paragraphs and will not be elaborated here. In one embodiment, the method of forming or depositing the second conductive layer 170 includes, but is not limited to, chemical vapor deposition, physical vapor deposition, plasma-assisted chemical vapor deposition, atomic layer deposition, electroplating, or other suitable processes and / or combinations thereof for deposition. Herein, the materials, materials, or components of the second conductive layer 170 have been detailed in the previous paragraphs and will not be elaborated here.

[0103] Next, please refer to Figure 7 , in Figure 6 An insulating layer 180 is formed on the formed light-emitting diode structure, and an etching process or a drilling process is performed to form a first opening 182 and a second opening 184. Among them, for the sake of concisely describing the necessary technologies, the step of pre-setting the resist layer is not drawn in Figure 7 . Specifically, the first opening 182 exposes a part of the upper surface of the first conductive layer 160, that is to say, the insulating layer 180 covers both side walls and another part of the upper surface of the first conductive layer 160. At the same time, the insulating layer 180 covers both side walls of the semiconductor contact layer 150 and a part of the upper surface that is not in contact with the first conductive layer 160. The second opening 184 exposes a part of the upper surface of the second conductive layer 170, that is to say, the insulating layer 180 covers another part of the upper surface of the second conductive layer 170 and both side walls of the second conductive layer 170. In one embodiment, the method of forming the insulating layer 180 includes, but is not limited to, chemical vapor deposition, physical vapor deposition, plasma-assisted chemical vapor deposition, atomic layer deposition, electroplating, or other suitable processes and / or combinations thereof for deposition. In one embodiment, the etching methods for forming the first opening 182 and the second opening 184 include, but are not limited to, wet etching, dry etching, chemical etching, physical etching, selective etching, or other suitable processes and / or combinations thereof for etching.

[0104] As shown in Figure 8As shown, in some embodiments, a first conductive pad 190a is formed in the first opening 182 and on a partial upper surface of the insulating layer 180. Among them, the first conductive pad 190a is electrically connected to the first conductive layer 160. In some embodiments, a second conductive pad 190b is formed in the second opening 184 and on a partial upper surface of the insulating layer 180, and the second conductive pad 190b is electrically connected to the second conductive layer 170. In one embodiment, the forming methods of the first conductive pad 190a and the second conductive pad 190b include, but are not limited to, chemical vapor deposition, physical vapor deposition, plasma-assisted chemical vapor deposition, atomic layer deposition, electroplating, or other suitable processes and / or combinations thereof for deposition.

[0105] Combining the above Figures 3 to 8 , the light-emitting diode structure in some embodiments of the present disclosure is completed. Its feature is that a semiconductor contact layer 150 is formed on the second thickness structure 124 of the first semiconductor layer 120. By reducing the energy gap required for carrier transmission between the first semiconductor layer 120 and the first conductive layer 160, the forward operating voltage is reduced, the alloy temperature and component waste heat are reduced, and the output power and component reliability are improved.

[0106] Example 2

[0107] Please refer to Figure 9 , Figure 9 which is a cross-sectional schematic diagram of a light-emitting diode structure according to some other embodiments of the present disclosure. It should be noted that Figure 9 the features of Figure 6 and Figure 7 can be referred to simultaneously and are described in detail as follows.

[0108] In some embodiments, the step of forming the first conductive layer 160 in the foregoing Figure 6 can be interchanged with the steps of forming the insulating layer 180 and the first opening 182 and the second opening 184 in Figure 7 . That is, only after first forming the second conductive layer 170 on the second semiconductor layer 140, the insulating layer 180 is directly formed on the light-emitting diode structure, and then the first opening 182 and the second opening 184 are etched. Specifically, the first opening 182 exposes a partial upper surface of the semiconductor contact layer 150, that is, the insulating layer 180 covers both side walls of the semiconductor contact layer 150 and another part of the upper surface.

[0109] As described above, after interchanging some steps between Figure 6 and Figure 7 , the first conductive layer 160 is continuously formed or deposited in the first opening 182 on the semiconductor contact layer 150. In one embodiment, the width of the first conductive layer 160 is substantially equal to the width of the first opening 182 ( Figure 9) Therefore, the width of the first conductive layer 160 is smaller than that of the semiconductor contact layer 150. Thus, after the first conductive layer 160 is formed, the insulating layer 180 is located on both sidewalls of the first conductive layer 160, and all upper surfaces of the first conductive layer 160 are exposed within the first opening 182.

[0110] In this embodiment, the subsequent steps are the same as those in Embodiment 1, that is, a first conductive pad 190a is formed within the first opening 182, on the first conductive layer 160, and on a partial upper surface of the insulating layer 180. Among them, the first conductive pad 190a is electrically connected to the first conductive layer 160. Moreover, a second conductive pad 190b is formed within the second opening 184 and on a partial upper surface of the insulating layer 180, and the second conductive pad 190b is electrically connected to the second conductive layer 170.

[0111] It should be noted that, for the sake of simplicity, the order exchange described in this embodiment is represented by Figure 9 The previous steps are only described in words and are not shown in the figures. However, the aforementioned process sequence should still be included within the scope of the rights described in this disclosure. Moreover, the types of processes for forming or manufacturing the aforementioned respective elements are the same as those in Embodiment 1, so they will not be elaborated here.

[0112] Embodiment 3

[0113] In some other embodiments of this disclosure, please refer to Figure 10 , Figure 10 which is a schematic cross-sectional view showing a light-emitting diode structure according to another embodiment of this disclosure. In the Figure 10 shown light-emitting diode structure, compared with Figure 2 , the main difference lies in the semiconductor contact layer 150'. In one embodiment, the semiconductor contact layer 150' includes a plurality of sub-contact layers 151, 152, 153, and 154. Please note that the four sub-contact layers 151, 152, 153, and 154 here are only exemplary and should not be used to limit this disclosure. More or fewer sub-contact layers than four should be within the scope of this disclosure.

[0114] In some embodiments, the doping concentration of each of the sub-contact layers 151, 152, 153, and 154 can be different, and each of the sub-contact layers 151, 152, 153, and 154 can be stacked in sequence from top to bottom according to the level of the doping concentration. That is, the doping concentration of each of the sub-contact layers 151, 152, 153, and 154 gradually decreases from the position close to the first conductive layer 160 towards the direction of the second thickness structure 124 of the first semiconductor layer 120. Specifically, in one embodiment aspect of this disclosure, the silicon doping concentration of the sub-contact layer 151 is about 2x10 19 / cm 3 , and the silicon doping concentration of the sub-contact layer 152 is about 4x10 19 / cm 3 , the silicon doping concentration of the sub-contact layer 153 is about 6x10 19 / cm 3 , while the silicon doping concentration of the sub-contact layer 154 is about 8x10 19 / cm 3 .

[0115] In some other embodiments, all of the sub-contact layers 151, 152, 153, and 154 have two or more doping concentrations and are alternately stacked from top to bottom according to the doping concentrations. That is, the stacking manner of each of the sub-contact layers 151, 152, 153, and 154 can be alternately stacked from top to bottom according to two or more doping concentrations. Specifically, in one embodiment of the present disclosure, the silicon doping concentration of the sub-contact layer 151 is about 4x10 19 / cm 3 , the silicon doping concentration of the sub-contact layer 152 is about 8x10 19 / cm 3 , the silicon doping concentration of the sub-contact layer 153 is about 4x10 19 / cm 3 , while the silicon doping concentration of the sub-contact layer 154 is about 8x10 19 / cm 3 . It can be seen therefrom that the stacking manner of each of the sub-contact layers 151, 152, 153, and 154 can be alternately stacked from top to bottom according to two or more doping concentrations.

[0116] In still some other embodiments, each of the sub-contact layers 151, 152, 153, and 154 includes Al x Ga y In 1-x-y N, where 0≤x,y≤1. And when x + y = 1 for each of the sub-contact layers 151, 152, 153, and 154, the doping concentration of the sub-contact layer 154 adjacent to the first conductive layer 160 is greater than that of the other sub-contact layers 151, 152, and 153. Specifically, in one embodiment of the present disclosure, each of the sub-contact layers 151, 152, 153, and 154 is Al x Ga y In 1-x-y N, and when 0≤x,y≤1 and x + y = 1, each of the sub-contact layers 151, 152, 153, and 154 does not contain indium (In). For example, the sub-contact layer 151 is Al 0.3 Ga 0.7 N, the sub-contact layer 152 is Al 0.2 Ga 0.8 N, the sub-contact layer 153 is Al 0.1 Ga 0.9N, and the sub-contact layer 154 is GaN. At this time, the silicon doping concentration of the sub-contact layer 151 is about 2x10 19 / cm 3 The silicon doping concentration of the sub-contact layer 152 is about 2.5x10 19 / cm 3 The silicon doping concentration of the sub-contact layer 153 is about 3.8x10 19 / cm 3 The silicon doping concentration of the sub-contact layer 154 is about 6x10 19 / cm 3 .

[0117] In some other embodiments, each of these sub-contact layers 151, 152, 153, and 154 includes Al x Ga y In 1-x-y N, where 0 ≤ x, y ≤ 1. Among them, the sub-contact layer 154 adjacent to the first conductive layer 160 is Ga y In 1-y N, where 0 < y < 1. That is to say, the sub-contact layers 151, 152, and 153 may or may not contain indium (In), and the sub-contact layer 154 adjacent to the first conductive layer 160 does not contain aluminum and must contain indium. The contact resistance with the first conductive layer 160 can be effectively reduced through the indium gallium nitride with a narrow surface energy gap, while the lattice mismatch between the indium gallium nitride and the underlying first semiconductor layer 120 can be buffered through the other graded aluminum indium gallium nitride. Specifically, in an embodiment of the present disclosure, the sub-contact layer 151 is Al 0.3 Ga 0.7 N, the sub-contact layer 152 is Al 0.2 Ga 0.7 In 0.1 N, the sub-contact layer 153 is Al 0.1 Ga 0.8 In 0.1 N, and the sub-contact layer 154 is Ga 0.9 In 0.1 N. That is, the sub-contact layers 151, 152, and 153 include Al x Ga y In 1-x-y N, where 0 ≤ x, y ≤ 1. And, the sub-contact layer 154 adjacent to the first conductive layer 160 is Ga y In 1-y N, where 0 < y < 1. In short, the sub-contact layers 151, 152, and 153 may or may not contain indium (In), and the sub-contact layer 154 adjacent to the first conductive layer 160 does not contain aluminum and must contain indium.

[0118] In still other embodiments, each of the sub-contact layers 151, 152, 153, and 154 may be arranged to be stacked in order of increasing or decreasing energy gap or to have at least two energy gaps stacked alternately. All of the sub-contact layers 151, 152, 153, and 154 have more than two energy gaps and are stacked alternately from top to bottom according to the energy gaps. That is, each of the sub-contact layers 151, 152, 153, and 154 may be stacked alternately from top to bottom according to more than two energy gaps. Specifically, in one embodiment of the present disclosure, the energy gap of the sub-contact layer 151 is about 2.4 eV, the energy gap of the sub-contact layer 152 is about 2.1 eV, the energy gap of the sub-contact layer 153 is about 2.0 eV, and the energy gap of the sub-contact layer 154 is about 1.5 eV. Each of the sub-contact layers 151, 152, 153, and 154 may be arranged to be stacked in order of increasing or decreasing energy gap. In another embodiment of the present disclosure, the energy gap of the sub-contact layer 151 is about 2.0 eV, the energy gap of the sub-contact layer 152 is about 1.5 eV, the energy gap of the sub-contact layer 153 is about 2.0 eV, and the energy gap of the sub-contact layer 154 is about 1.5 eV. Each of the sub-contact layers 151, 152, 153, and 154 may be stacked alternately from top to bottom according to more than two energy gaps.

[0119] Embodiment 4

[0120] Please refer to Figure 11 and Figure 12 , Figure 11 which is a top view of a light-emitting diode structure according to some embodiments of the present disclosure. Figure 12 is a schematic cross-sectional view taken along the section line BB' in Figure 11 . Figure 11 and Figure 12 show the same light-emitting diode structure as described above in Figure 1 and Figure 2 , however, Figure 12 is viewed with the section line BB' in Figure 11 as the reference view. As can be seen from Figure 12 , in some embodiments, the semiconductor contact layer 150 located above the second thickness structure 124 of the first semiconductor layer 120 has a continuous and integrally formed structure. However, the semiconductor contact layer 150 described in the present disclosure may also have a non-continuous or non-integrally formed structure, the characteristics and structure of which are described in detail below.

[0121] In still other embodiments, please refer to Figure 13 and Figure 14 simultaneously. Figure 13 is a top view of a light-emitting diode structure according to still other embodiments of the present disclosure. Note that the first semiconductor layer 120, the light-emitting layer 130, and the second semiconductor layer 140 are not shown in Figure 13 . Figure 14 is a schematic cross-sectional view taken alongFigure 13 Schematic cross-sectional view of the cross-section line CC'. In some further embodiments of the present disclosure, such as Figure 13 shown, the semiconductor contact layer 150 includes a plurality of independent contact layers 155 and an insulating portion 156, and any two adjacent independent contact layers 155 are spaced apart from each other by the insulating portion 156. Specifically, the independent contact layers 155 and the insulating portion 156 are alternately arranged. Moreover, each independent contact layer 155 is electrically connected to the first semiconductor layer 120 and the first conductive layer 160. Additionally, in one embodiment, the insulating portion 156 will be connected to and cover the light-emitting diode structure with a subsequently formed insulating layer 180. In one embodiment, after the semiconductor contact layer 150 is formed, the independent contact layers 155 can be formed by, but not limited to, wet etching, dry etching, chemical etching, physical etching, selective etching or other suitable processes and / or combinations thereof for etching. In one embodiment, the insulating portion 156 between each independent contact layer 155 can be formed by, but not limited to, chemical vapor deposition, physical vapor deposition, plasma-assisted chemical vapor deposition, atomic layer deposition, electroplating or other suitable processes and / or combinations thereof for deposition. In one embodiment, the material of the insulating portion 156 can include, but not limited to, silicon oxide, silicon nitride, silicon oxynitride, epoxy resin or other suitable insulating materials. In one embodiment, the shape of the insulating portion 156 can include, but not limited to, dot-shaped, block-shaped, spherical or other suitable shapes.

[0122] As described above, when the semiconductor contact layer 150 is processed to form a plurality of independent contact layers 155, the overall area of the semiconductor contact layer 150 will be reduced, thereby reducing the light absorption probability of the semiconductor contact layer 150. At the same time, because the insulating portion 156 is filled between each independent contact layer 155, the current is dispersed, and the forward operating voltage is further reduced.

[0123] Example 5

[0124] Please refer to Figure 4 、 Figure 15 and Figure 16 simultaneously, Figure 15 which is a top view of a light-emitting diode structure showing some further embodiments of the present disclosure. Figure 16 which is a schematic cross-sectional view of the cross-section line DD' shown in Figure 15 . Note that for ease of reference, Figure 16 the insulating layer 180 and the conductive pad 190 in Figure 15 are not shown in Figure 4 . In some further embodiments of the present disclosure, in the etching step of Figure 15 , the etched portion can be adjusted to form a light-emitting diode structure as shown in Figure 15Among them, the parts where the semiconductor contact layer 150 is provided are all etched parts, which are different from Figure 4 Etching is only performed at one end of the light-emitting diode structure. Further, through the cross-section line DD’, the etched light-emitting diode structure is as Figure 16 shown. The position where the semiconductor contact layer 150 is located is the second thickness structure 124. On both sides away from the semiconductor contact layer 150, there can be a layered structure composed of the first thickness structure 122 of the first semiconductor layer 120, the light-emitting layer 130, the second semiconductor layer 140, and so on.

[0125] As described above, in this embodiment, three layered structures composed of the first thickness structure 122 of the first semiconductor layer 120, the light-emitting layer 130, the second semiconductor layer 140, and so on are formed. However, it should be noted that the formed state here is only for illustrative purposes, and more or fewer layered structures or semiconductor contact layer 150 should all fall within the scope of this disclosure.

[0126] Embodiment 6

[0127] Please also refer to Figure 17 and Figure 18 , Figure 17 which is a top view of a light-emitting diode structure according to some further embodiments of this disclosure. It should be noted that the first semiconductor layer 120 is not shown in Figure 15 . Figure 18 is a cross-sectional schematic diagram of the cross-section line EE’ in Figure 17 . Similar to the implementation states of Figure 13 and Figure 14 , in this embodiment, the semiconductor contact layer 150 includes a plurality of independent contact layers 155 and an insulating portion 156, and any two adjacent independent contact layers 155 are spaced apart from each other by the insulating portion 156. Additionally, in one implementation, the insulating portion 156 will be connected to and cover the light-emitting diode structure with a subsequently formed insulating layer 180. And each independent contact layer 155 is electrically connected to the first semiconductor layer 120 and the first conductive layer 160. In one embodiment, the etching and forming methods of the independent contact layer 155 and the insulating portion 156 described in this embodiment are the same as those in the foregoing Embodiment 4, so they will not be elaborated here. And the material of the insulating portion 156 is also the same as that in Embodiment 4.

[0128] As described above, when the semiconductor contact layer 150 is processed to form a plurality of independent contact layers 155, the overall area of the semiconductor contact layer 150 will be reduced, thereby reducing the light absorption probability of the semiconductor contact layer 150. At the same time, because the insulating portion 156 is filled between each independent contact layer 155, the current is dispersed, and the forward operating voltage is further reduced.

[0129] Embodiment 7

[0130] Please also refer to Figure 19 and Figure 20 , Figure 19 which is a top view of a light-emitting diode structure according to some further embodiments of the present disclosure. Figure 20 which is a schematic cross-sectional view along the section line FF' in Figure 19 . Note that, for ease of reference, Figure 20 the conductive connection layer CL, the insulating layer 180, and the conductive pad 190 in Figure 19 are not shown in Figure 19 . As shown in Figure 20 , in a top view, it can be seen that the light-emitting diode structure of the present disclosure includes a plurality of semiconductor contact layers 150 and a plurality of first conductive layers 160 located on the plurality of semiconductor contact layers 150. Then, referring to Figure 20 through the section line FF', since each semiconductor contact layer 150 is electrically isolated from each other, a conductive connection layer CL is provided to electrically connect each semiconductor contact layer 150 to each other and further electrically connect each semiconductor contact layer 150 and the first conductive pad 190. In one embodiment, after forming the light-emitting diode structure as shown in Figure 3 , a plurality of holes are formed by processes such as drilling or etching. The formation methods of the foregoing plurality of holes include, but are not limited to, wet etching, dry etching, chemical etching, physical etching, selective etching, or other suitable processes and / or combinations thereof for etching. Then, each semiconductor contact layer 150 and the first conductive layer 160 are formed in the holes. The formation methods include, but are not limited to, chemical vapor deposition, physical vapor deposition, plasma-assisted chemical vapor deposition, atomic layer deposition, electroplating, or other suitable processes and / or combinations thereof for deposition. In one embodiment, the material of the conductive connection layer CL includes, but is not limited to, a transparent conductive material including indium tin oxide, indium zinc oxide, aluminum zinc oxide, or a material having a transparent conductive effect; or an opaque metal material. For example, the opaque metal material includes chromium, gold, titanium, aluminum, vanadium, or other similar opaque metal materials.

[0131] Through the above description, the overall area of each semiconductor contact layer 150 is reduced, thereby reducing the light absorption probability of the semiconductor contact layer 150 and further reducing the forward operating voltage. It should be noted that the aspects shown here are only illustrative, and more or fewer semiconductor contact layers 150 should be included within the scope of the present disclosure.

[0132] Example 8

[0133] Please refer to Figure 21 , Figure 21FIG. is a cross-sectional schematic diagram of a light-emitting diode structure according to some further embodiments of the present disclosure. In this embodiment, the light-emitting diode structure includes a substrate 110, a first conductive layer 160, an insulating layer 180, a second conductive layer 170, a second semiconductor layer 140, a light-emitting layer 130, a semiconductor contact layer 150, and a first semiconductor layer 120. In one embodiment, as Figure 21 shown, the second conductive layer 170 is disposed on the substrate 110. The second semiconductor layer 140 is disposed on the second conductive layer 170. The light-emitting layer 130 is disposed on the second semiconductor layer 140. The first semiconductor layer 120 is disposed on the light-emitting layer 130, and the doping type of the first semiconductor layer 120 is different from that of the second semiconductor layer 140. The first conductive layer 160 is disposed between the substrate 110 and the second conductive layer 170. The first conductive layer 160 includes a base portion 160a and a protruding portion 160b. The protruding portion 160b penetrates through the second conductive layer 170, the second semiconductor layer 140, and the light-emitting layer 130 to be electrically connected to the first semiconductor layer 120. The insulating layer 180 is disposed between the first conductive layer 160 and the second conductive layer 170. The semiconductor contact layer 150 is disposed between the protruding portion 160b of the first conductive layer 160 and the first semiconductor layer 120, and the doping type of the semiconductor contact layer 150 is the same as that of the first semiconductor layer 120. Among them, the protruding portion 160b of the first conductive layer 160 and the semiconductor contact layer 150 are both electrically isolated from the second conductive layer 170, the second semiconductor layer 140, and the light-emitting layer 130 through the extending portion 180b of the insulating layer 180. It should be noted that the materials and formation methods of the light-emitting diode structure and its components described in this embodiment have been described in the foregoing embodiments, so they will not be repeated here.

[0134] Embodiment 9

[0135] Regarding the semiconductor contact layer 150 formed in the foregoing Embodiments 1 to 8, it may have a plurality of through holes 157. It should be noted that, for the sake of simplicity, the through holes 157 are not shown in the Figures 1 to 21 semiconductor contact layer 150. Regarding the foregoing plurality of through holes 157, please refer to Figure 22 , Figure 22 FIG. is a schematic diagram of the semiconductor contact layer 150 in a light-emitting diode structure according to some further embodiments of the present disclosure. From Figure 22It can be seen that after magnifying a part of the semiconductor contact layer 150 and the first conductive layer 160 in the light-emitting diode structure, it can be found that the appearance of the semiconductor contact layer 150 has a plurality of through holes 157. Regarding the through holes 157, when the semiconductor contact layer 150 is formed by a secondary growth process and the thickness of the formed semiconductor contact layer 150 is relatively thin, the state of the semiconductor contact layer 150 will be an incomplete thin film. That is to say, there will be a plurality of randomly distributed through holes 157 in the semiconductor contact layer 150. Then, when the first conductive layer 160 is formed on the semiconductor contact layer 150 in a subsequent process, a part of the first conductive layer 160 will fill into these through holes 157. Further, the contact area between the semiconductor contact layer 150 and the first conductive layer 160 increases, and the contact resistance can be more effectively reduced. In an embodiment of the present disclosure, the thickness of the semiconductor contact layer 150 formed by the secondary growth process is between about 400 nm and about 50 nm.

[0136] In summary, the present disclosure grows a thin semiconductor contact layer (or ohmic contact layer) on the surface of the N-type semiconductor not covered by the light-emitting layer, so that an ohmic contact is formed for the N-type electrode. In this way, the forward operating voltage, alloy temperature and component waste heat can be reduced, the output power can be increased, and the component reliability can be improved, while not affecting the epitaxial crystal quality of the light-emitting layer.

[0137] The foregoing disclosure outlines the features of several embodiments, enabling those skilled in the art to better understand various aspects of the present disclosure. Those skilled in the art will understand that they can easily use the present disclosure as a basis for designing or modifying other processes and structures to achieve the same purposes and / or achieve the same benefits as the embodiments introduced in the present disclosure. Those skilled in the art should also understand that although the present disclosure has been disclosed in multiple embodiments as above, it is not intended to limit the present disclosure. Any person familiar with this art can make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be determined by the scope defined in the appended claims.

Claims

1. A light-emitting diode structure, characterized in that, comprising: a substrate; a first semiconductor layer disposed on the substrate, the first semiconductor layer comprising: a first thickness structure; and a second thickness structure, wherein a first thickness of the first thickness structure is greater than a second thickness of the second thickness structure; a light-emitting layer disposed on the first thickness structure of the first semiconductor layer; a second semiconductor layer disposed on the light-emitting layer, a doping type of the second semiconductor layer being different from a doping type of the first semiconductor layer; a semiconductor contact layer disposed on the second thickness structure of the first semiconductor layer, wherein a vertical projection of the semiconductor contact layer and the light-emitting layer on the substrate do not overlap or contact each other, a doping type of the semiconductor contact layer is the same as a doping type of the first semiconductor layer, and the semiconductor contact layer includes a plurality of through holes that penetrate the semiconductor contact layer along a thickness direction; a first conductive layer disposed on the semiconductor contact layer; and a second conductive layer disposed on the second semiconductor layer.

2. The light-emitting diode structure according to claim 1, characterized in that, further comprising: an insulating layer that covers sidewalls of the first thickness structure, an upper surface of the second thickness structure, sidewalls of the light-emitting layer, sidewalls of the second semiconductor layer, sidewalls and an upper surface of the semiconductor contact layer, sidewalls of the first conductive layer, and sidewalls and an upper surface of the second conductive layer, and the insulating layer has a first opening and a second opening respectively located above the first conductive layer and the second conductive layer; and a first conductive pad and a second conductive pad disposed on the insulating layer and electrically connected to the first conductive layer and the second conductive layer respectively through the first opening and the second opening.

3. The light-emitting diode structure according to claim 1, characterized in that, The semiconductor contact layer comprises Al x Ga y In 1-x-y N, where 0 ≤ x, y ≤ 1.

4. The light-emitting diode structure according to claim 3, characterized in that, When x + y = 1, the doping concentration of the semiconductor contact layer is greater than 1x10 19 / cm 3 .

5. The light-emitting diode structure according to claim 1, characterized in that, a thickness of the semiconductor contact layer is between 1 nm and 500 nm.

6. The light-emitting diode structure according to claim 1, characterized in that, a doping concentration of the semiconductor contact layer is higher than a doping concentration of the first semiconductor layer.

7. The light-emitting diode structure according to claim 1, characterized in that, the semiconductor contact layer includes a plurality of sub-contact layers, doping concentrations of the respective sub-contact layers are the same or different, and the respective sub-contact layers are arranged to be stacked in order of increasing or decreasing doping concentration or at least two doping concentrations are stacked alternately.

8. The light-emitting diode structure according to claim 1, characterized in that, The semiconductor contact layer includes a plurality of sub-contact layers, and the plurality of sub-contact layers include Al x Ga y In 1-x-y N, where 0 ≤ x, y ≤ 1. When x + y = 1 for each of the sub-contact layers, the doping concentration of the sub-contact layer adjacent to the first conductive layer is greater than the doping concentrations of the other sub-contact layers.

9. The light-emitting diode structure according to claim 1, characterized in that, The semiconductor contact layer includes a plurality of sub-contact layers, and the plurality of sub-contact layers include Al x Ga y In 1-x-y N, where 0 ≤ x, y ≤ 1. Among them, the sub-contact layer adjacent to the first conductive layer is Ga y In 1-y N, where 0 < y < 1.

10. The light-emitting diode structure according to claim 1, characterized in that, the semiconductor contact layer includes a plurality of sub-contact layers, and the respective sub-contact layers are arranged to be stacked in order of increasing or decreasing bandgap or at least two bandgaps are stacked alternately.

11. The light-emitting diode structure according to claim 1, characterized in that, The semiconductor contact layer includes a plurality of independent contact layers, and all of the plurality of independent contact layers are electrically connected to the first semiconductor layer and the first conductive layer, and any two adjacent independent contact layers are spaced apart from each other by an insulating portion.

12. The light-emitting diode structure according to claim 10, wherein, the semiconductor contact layer includes a plurality of independent contact layers, and all of the plurality of independent contact layers are electrically connected to the first semiconductor layer and the first conductive layer, and any two adjacent independent contact layers are spaced apart from each other by an insulating portion.

13. The light-emitting diode structure according to claim 1, wherein, the number of the semiconductor contact layers is plural, the light-emitting layer is included between any two adjacent semiconductor contact layers, and the number of the first conductive layers is plural, and the first conductive layers are respectively disposed on the semiconductor contact layers.

14. The light-emitting diode structure according to claim 13, wherein, it further includes a conductive connection layer disposed on the first conductive layer and configured to electrically connect each of the first conductive layers.

15. A light-emitting diode structure, wherein, it includes: a substrate; a second conductive layer disposed on the substrate; a second semiconductor layer disposed on the second conductive layer; a light-emitting layer disposed on the second semiconductor layer; a first semiconductor layer disposed on the light-emitting layer, and the doping type of the first semiconductor layer is different from that of the second semiconductor layer; a first conductive layer disposed between the substrate and the second conductive layer, and the first conductive layer includes a base portion and a protruding portion, and the protruding portion penetrates through the second conductive layer, the second semiconductor layer and the light-emitting layer to be electrically connected to the first semiconductor layer; an insulating layer disposed between the first conductive layer and the second conductive layer; and a semiconductor contact layer disposed between the protruding portion of the first conductive layer and the first semiconductor layer, and the doping type of the semiconductor contact layer is the same as that of the first semiconductor layer, and the semiconductor contact layer includes a plurality of through holes, and the plurality of through holes penetrate through the semiconductor contact layer along the thickness direction; wherein, the protruding portion of the first conductive layer and the semiconductor contact layer are both electrically isolated from the second conductive layer, the second semiconductor layer and the light-emitting layer through an extension portion of the insulating layer.

16. The light-emitting diode structure according to claim 15, wherein, the doping concentration of the semiconductor contact layer is higher than that of the first semiconductor layer.

17. The light-emitting diode structure according to claim 15, wherein, the semiconductor contact layer includes a plurality of sub-contact layers, the doping concentration of each sub-contact layer is the same or different, and the arrangement of each sub-contact layer is to be stacked in sequence according to the doping concentration from high to low or at least two doping concentrations are stacked alternately.

18. The light-emitting diode structure according to claim 15, wherein, the semiconductor contact layer includes a plurality of independent contact layers, any two adjacent independent contact layers are spaced apart from each other by an insulating portion, and each independent contact layer is electrically connected to the first semiconductor layer and the first conductive layer.

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