Light emitting diode and method of manufacturing the same

Abstract

The present application provides a light emitting diode and a manufacturing method thereof. The light emitting diode comprises a conductive substrate, a transparent conductive layer and an epitaxial composite layer. The transparent conductive layer has a plurality of conductive pegs arranged on the conductive substrate. The epitaxial composite layer has a light emitting layer and a first conductive type in-situ doped epitaxial bottom layer arranged on the transparent conductive layer. The first conductive type in-situ doped epitaxial bottom layer has a second conductive type local diffusion region arranged in the first conductive type in-situ doped epitaxial bottom layer and in contact with the conductive pegs, so that the current flowing through the light emitting layer substantially directly flows into the conductive pegs through the second conductive type local diffusion region.

Description

Technical Field

[0001] This invention relates to a light-emitting diode and a method for manufacturing the same, and particularly to a high-brightness light-emitting diode and a method for manufacturing the same. Background Technology

[0002] Light-emitting diodes (LEDs) have advantages such as high brightness, small size, low power consumption, and long lifespan, and are widely used in optoelectronic products such as lighting and displays. Please refer to [link / reference]. Figure 1 It displays the design of currently common high-brightness LEDs. Figure 1 The displayed light-emitting diode has an epitaxial composite layer 20 disposed on a substrate 10, which includes a P-type epitaxial layer 21, a light-emitting layer 22, and an N-type epitaxial layer 23. A transparent conductive layer 30 is sandwiched between the substrate and the epitaxial composite layer 20, and a plurality of conductive plugs 32 are disposed in the transparent conductive layer 30. These conductive plugs 32 serve as ohmic contacts between the epitaxial layer and the metal reflective layer and for current diffusion distribution.

[0003] In actual operation, the external current injected into this conventional light-emitting diode (LED) from the upper electrode 40 partially flows along path A as shown in the figure, passing through the light-emitting layer 22 and the P-type epitaxial layer 21, before flowing into the conductive plug 32. However, a portion of the current may flow below the upper electrode 40 due to the low resistance between the PN junctions. As shown in the figure, it flows along path B, passing through the light-emitting layer 22 and the P-type epitaxial layer 21 below the upper electrode, and finally into the conductive plug 32. When the current on path B flows into the light-emitting layer 22, the light it generates may be partially overlapped with the upper electrode 40 in the vertical direction, thus being blocked by the upper electrode 40, reducing the efficiency of light emission and causing pad shading problems.

[0004] On the other hand, after the MESA (Medium-Etching Asphalt) etching process, the sidewalls of the epitaxial layer of a light-emitting diode (LED) are affected by the etching, resulting in more lattice defects within the epitaxial layer. This makes the outer sidewalls susceptible to electrical overstress (EOS) or electrostatic discharge (ESD) attacks, leading to failure and leakage problems. To overcome these issues, the industry urgently needs an innovative LED and manufacturing method to improve brightness and increase ESD resistance. Summary of the Invention

[0005] The main objective of this invention is to provide a high-brightness light-emitting diode (LED) with anti-static properties and a method for manufacturing the same. Specifically, this invention utilizes a localized impurity doping and diffusion process to precisely control the current path distribution within the LED. This prevents the light-emitting area generated in the current path from being blocked by the electrode pads in the vertical direction, thereby enhancing brightness. Simultaneously, this invention also allows for control over current flow in the peripheral region of the epitaxial layer, improving the device's anti-static capability.

[0006] To achieve the above objectives, the present invention provides a light-emitting diode (LED) comprising a conductive substrate, a transparent conductive layer, and an epitaxial composite layer. The transparent conductive layer has a plurality of conductive plugs disposed on the conductive substrate. The epitaxial composite layer has a light-emitting layer and a first conductivity type in-situ doped epitaxial layer disposed on the transparent conductive layer. The first conductivity type in-situ doped epitaxial layer has a second conductivity type local diffusion region disposed within the first conductivity type in-situ doped epitaxial layer and in contact with the conductive plugs, such that the current flowing through the light-emitting layer substantially flows directly into the conductive plugs through the second conductivity type local diffusion region.

[0007] In one embodiment of the light-emitting diode of the present invention, the first conductivity type in-situ doped epitaxial layer is an N-type indium phosphide (InP) epitaxial layer, and the second conductivity type local diffusion region is a P-type indium phosphide (InP) local diffusion region.

[0008] In one embodiment of the light-emitting diode of the present invention, there is a gap between the second conductive local diffusion region and the sidewall of the epitaxial composite layer, so that the second conductive local diffusion region does not touch the sidewall of the epitaxial composite layer.

[0009] In one embodiment of the light-emitting diode of the present invention, the light-emitting diode further includes an upper electrode disposed on an epitaxial composite layer, wherein the upper electrode and the second conductive local diffusion region do not overlap in the vertical direction, so that the current injected from the upper electrode flows through the light-emitting layer and substantially directly into the conductive plug through the second conductive local diffusion region.

[0010] In one embodiment of the light-emitting diode of the present invention, the light-emitting layer is an indium gallium arsenide (InGaAs) intrinsic epitaxial layer.

[0011] In one embodiment of the light-emitting diode of the present invention, the light-emitting layer is a second conductivity type lightly doped indium gallium arsenide (InGaAs) epitaxial layer.

[0012] In one embodiment of the light-emitting diode of the present invention, each conductive plug is a second type of conductive ohmic contact plug.

[0013] In one embodiment of the light-emitting diode of the present invention, the second conductive ohmic contact is a P-type indium gallium arsenide phosphide (InGaAsP) conductive contact.

[0014] To achieve the above objectives, the present invention provides a light-emitting diode (LED) comprising a conductive substrate, an epitaxial composite layer, and a top electrode. The epitaxial composite layer has a light-emitting layer and a first conductivity type in-situ doped epitaxial layer. The first conductivity type in-situ doped epitaxial layer has a second conductivity type local diffusion region disposed within the first conductivity type in-situ doped epitaxial layer and does not overlap with the top electrode in the vertical direction, so that current injected from the top electrode flows substantially directly into the conductive substrate through the second conductivity type local diffusion region after passing through the light-emitting layer.

[0015] In another embodiment of the light-emitting diode of the present invention, the first conductivity type in-situ doped epitaxial layer is an N-type indium phosphide (InP) epitaxial layer, and the second conductivity type local diffusion region is a P-type indium phosphide (InP) local diffusion region.

[0016] In another embodiment of the light-emitting diode of the present invention, there is a gap between the second conductive local diffusion region and the sidewall of the epitaxial composite layer, so that the second conductive local diffusion region does not touch the sidewall of the epitaxial composite layer.

[0017] In another embodiment of the light-emitting diode of the present invention, the light-emitting diode further includes a transparent conductive layer having a plurality of conductive plugs disposed between the conductive substrate and the epitaxial composite layer, and forming an ohmic contact with the second conductive local diffusion region, so that the current injected from the upper electrode flows through the light-emitting layer and substantially directly flows into the conductive plugs through the second conductive local diffusion region.

[0018] In another embodiment of the light-emitting diode of the present invention, each conductive plug is a P-type indium gallium arsenide phosphide (InGaAsP) conductive plug.

[0019] In another embodiment of the light-emitting diode of the present invention, the light-emitting layer is an indium gallium arsenide (InGaAs) intrinsic epitaxial layer.

[0020] In another embodiment of the light-emitting diode of the present invention, the light-emitting layer is a second conductivity type lightly doped indium gallium arsenide (InGaAs) epitaxial layer.

[0021] To achieve the above objectives, the present invention provides a method for manufacturing a light-emitting diode (LED), comprising the following steps: First, an epitaxial composite layer is provided on an epitaxial growth substrate, the epitaxial composite layer having a light-emitting layer and a first conductivity type in-situ doped epitaxial underlayer. Second, a plurality of conductive plugs are provided on the epitaxial composite layer. Next, a second conductivity type local diffusion region is provided in the first conductivity type in-situ doped epitaxial underlayer, forming an ohmic contact with the conductive plugs. Finally, a conductive substrate is provided and wafer-bonded to the epitaxial growth substrate, and the epitaxial growth substrate is removed, wherein the current flowing through the light-emitting layer substantially flows directly through the second conductivity type local diffusion region into the conductive plugs and into the conductive substrate.

[0022] In one embodiment of the LED manufacturing method of the present invention, the step of providing a second conductive local diffusion region involves providing a patterned mask layer disposed on the epitaxial composite layer and exposing the conductive plugs for an ion doping and diffusion process.

[0023] In one embodiment of the light-emitting diode manufacturing method of the present invention, the step of providing an ion doping and diffusion process is to create a gap between the second conductive local diffusion region and the sidewall of the epitaxial composite layer, and to ensure that the second conductive local diffusion region does not touch the sidewall of the epitaxial composite layer.

[0024] In one embodiment of the light-emitting diode manufacturing method of the present invention, the manufacturing method further includes providing an upper electrode disposed on an epitaxial composite layer, wherein the upper electrode and the second conductive local diffusion region do not overlap in the vertical direction, so that the current injected from the upper electrode flows through the light-emitting layer and substantially directly through the second conductive local diffusion region into the conductive plug and into the conductive substrate.

[0025] In one embodiment of the light-emitting diode manufacturing method of the present invention, the step of providing an epitaxial composite layer includes providing a second conductivity type lightly doped indium gallium arsenide (InGaAs) epitaxial layer as a light-emitting layer.

[0026] Other objects of the present invention, as well as the technical means and implementation methods of the present invention, will be understood by those skilled in the art upon referring to the accompanying drawings and the embodiments described below. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a traditional light-emitting diode (LED).

[0028] Figures 2 to 9 This is a schematic diagram illustrating the manufacture of a light-emitting diode according to one embodiment of the present invention;

[0029] Figure 10 This is a schematic diagram of the current path of the light-emitting diode in one embodiment of the present invention;

[0030] Figure 11This is a schematic diagram of the energy band of the epitaxial layer of a light-emitting diode in one embodiment of the present invention;

[0031] Figure 12 This is a top view schematic diagram of a light-emitting diode according to an embodiment of the present invention; and

[0032] Figure 13 This is a schematic diagram of the manufacturing process steps of the light-emitting diode of the present invention.

[0033] Explanation of reference numerals in the attached figures

[0034] 10 Substrates

[0035] 20 Epitaxial Composite Layer

[0036] 21 P-type epitaxial layer

[0037] 22. Light-emitting layer

[0038] 23 N-type epitaxial layer

[0039] 30 Transparent conductive layer

[0040] 32 conductive plugs

[0041] 40 Upper electrode

[0042] 100 Epitaxial Growth Substrate

[0043] 101 Epitaxial Composite Layer

[0044] 102 Essential Epitaxial Layer

[0045] 103 Buffer Epitaxial Layer

[0046] 104 First conductivity type in-situ doped epitaxial layer

[0047] 105 Emissive Layer

[0048] 106 First conductivity type in-situ doped epitaxial layer

[0049] 107 Essential Epitaxial Layer

[0050] 108 conductive plugs

[0051] 109th layer of curtain

[0052] 110 Second type of localized diffusion region

[0053] 111 Transparent conductive layer

[0054] 112 Mirror Layer

[0055] 113 Conductive substrate

[0056] 114 Upper Electrode

[0057] 115 Lower electrode

[0058] Path A

[0059] Path B

[0060] C path

[0061] S interval

[0062] XY line segments. Detailed Implementation

[0063] The following embodiments will explain the content of this invention. These embodiments are not intended to limit the implementation of this invention to any specific environment, application, or special method described in the embodiments. Therefore, the descriptions of the embodiments are merely illustrative of the invention and not intended to limit it. It should be noted that in the following embodiments and accompanying drawings, elements not directly related to this invention have been omitted and are not shown, and the dimensional relationships between the elements in the drawings are for ease of understanding only and are not intended to limit the actual scale.

[0064] This invention discloses a light-emitting diode (LED) and its manufacturing method. Specifically, the LED disclosed in this invention achieves uniform current distribution and diffusion through the arrangement of locally diffused epitaxial layers, thereby improving the light extraction efficiency of the LED, as detailed below. Please refer to... Figure 2 This illustration shows a short-wave infrared light-emitting diode in one embodiment of the present invention, using indium phosphide (InP) as an epitaxial growth substrate 100, but is not limited thereto. Next, an epitaxial composite layer 101 is first epitaxially grown on this epitaxial growth substrate 100 using metal-organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE) techniques. This epitaxial composite layer 101 includes an intrinsic epitaxial layer 102, such as an indium phosphide (InP) layer, to ensure high-quality epitaxial growth. Secondly, a buffer epitaxial layer 103, such as an indium gallium arsenide (InGaAs) epitaxial layer, is grown on the intrinsic epitaxial layer 102 for lattice matching between subsequently grown light-emitting layers and for forming good ohmic contacts with electrodes.

[0065] Secondly, the epitaxial composite layer 101 further comprises, sequentially on the buffer epitaxial layer 103, a first conductivity type in-situ doped epitaxial layer 104, a light-emitting layer 105, and a first conductivity type in-situ doped epitaxial layer 106. The light-emitting layer 105 is a multiple quantum well (MQW) structure, specifically a pure indium gallium arsenide (InGaAs) epitaxial layer sandwiched between two first conductivity type in-situ doped epitaxial layers. In a preferred embodiment, this light-emitting layer 105 can be a p-type lightly doped indium gallium arsenide (InGaAs) epitaxial layer. In this embodiment, the emission wavelength of the light-emitting layer 105 can be 1100–1700 nanometers (nm). It should be noted that the material described above for the light-emitting layer is merely one embodiment, and the present invention is not limited thereto. In practical applications, the materials and their composition can be adjusted according to the emission wavelength. For example, the epitaxial layer can be aluminum gallium indium phosphide (AlGaInP), indium gallium phosphide (InGaP), aluminum gallium arsenide (AlGaAs), etc.

[0066] On the other hand, the first conductivity type in-situ doped epitaxial layer 104 and the first conductivity type in-situ doped epitaxial layer 106 are specifically N-type lightly doped indium phosphide (InP) epitaxial layers, whose doping elements, for example, but not limited to, sulfur (S) or silicon (Si), have a doping concentration of about 10. 16～17 (cm -3 Finally, during the epitaxial process, an intrinsic epitaxial layer 107 is further extended on the first conductivity type in-situ doped epitaxial layer 106, for example, but not limited to, an intrinsic indium gallium arsenide phosphide (InGaAsP) epitaxial layer, to serve as a conductive plug for subsequent ohmic contact layers.

[0067] Please see Figure 3 Next, a patterning process is performed. Based on the requirement for uniform current distribution and diffusion in the light-emitting diode, and in conjunction with the subsequent electrode pad pattern design, a portion of the intrinsic epitaxial layer 107 is removed to form multiple patterned intrinsic epitaxial layers 107 on top of the first conductivity type in-situ doped epitaxial layer 106. (See also...) Figure 4 and Figure 5 This demonstrates a localized ion doping and diffusion process. Specifically, a patterned mask layer 109 is formed on the first conductivity type in-situ doped epitaxial layer 106 to expose multiple patterned intrinsic epitaxial layers 107 on the surface of the first conductivity type in-situ doped epitaxial layer 106, and a portion of the exposed surface of the first conductivity type in-situ doped epitaxial layer 106 around the patterned intrinsic epitaxial layers 107. Next, an ion doping and diffusion process is performed to form a second conductivity type localized diffusion region 110 in the partially exposed area of ​​the first conductivity type in-situ doped epitaxial layer 106, such as... Figure 5 As shown. Specifically, please refer to... Figure 12It shows a top view of a light-emitting diode according to an embodiment of the present invention, wherein, Figure 5 yes Figure 12 A schematic cross-sectional view of the midline segment XY. Figure 12 The image clearly shows the second conductivity type local diffusion region 110, which is the region in the first conductivity type in-situ doped epitaxial layer 106 that has undergone the aforementioned ion doping diffusion. In contrast, the area outside the second conductivity type local diffusion region 110 belongs to the region of the first conductivity type in-situ doped epitaxial layer 106 that has not undergone ion doping diffusion.

[0068] Specifically, it can involve doping with elements such as zinc (Zn) or carbon (C) at a doping concentration of approximately 10. 16～17 (cm -3 The ion doping and diffusion process forms a localized low-resistivity P-type contact doped diffusion region. It should be emphasized that the pattern outline of this second conductivity type local diffusion region 110 is based on the upper electrode 114 (as intended) to be formed in subsequent processes. Figure 12 The pattern shown is designed so that the two do not overlap in the vertical direction, thereby achieving uniform current distribution and preventing obstruction by the upper electrode, thus improving the light extraction efficiency, as detailed later. Furthermore, this second conductive local diffusion region 110 also has another feature: a gap S exists between its outer contour and the sidewall of the epitaxial composite layer 101, ensuring that the second conductive local diffusion region 110 does not touch the sidewall of the epitaxial composite layer 101, thereby increasing the antistatic capability of the light-emitting diode, as detailed later.

[0069] On the other hand, in a preferred embodiment of the present invention, the original multiple patterned intrinsic epitaxial layers 107 will be simultaneously converted into multiple patterned second conductivity epitaxial layers due to the simultaneous influence of ion doping and diffusion processes. As mentioned above, when the intrinsic epitaxial layer 107 is an intrinsic indium gallium arsenide phosphide (InGaAsP) epitaxial layer, after ion doping and diffusion processes, the multiple patterned second conductivity epitaxial layers will become multiple patterned second conductivity indium gallium arsenide phosphide (InGaAsP) epitaxial layers, specifically multiple patterned P-type indium gallium arsenide phosphide (InGaAsP) epitaxial layers, serving as multiple conductive plugs 108 in the subsequent light-emitting diode structure, and can form good ohmic contact with the metal reflective layer formed in the subsequent process (that is, the conductive plug 108 is a second conductivity ohmic contact plug, more specifically, a P-type indium gallium arsenide phosphide (InGaAsP) conductive plug), such as Figure 5 and Figure 12 As shown.

[0070] Please see Figure 6After removing the patterned mask layer 109, a transparent conductive layer 111 is then formed on the wafer surface by vapor deposition, covering multiple conductive plugs 108, an undoped and diffused first conductivity type in-situ doped epitaxial layer 106, and a second conductivity type local diffusion region 110, and electrically connected to the conductive plugs 108. The transparent conductive layer 111 is composed of indium tin oxide (ITO), aluminum zinc oxide (AZO), zinc tin oxide (IZO), nickel oxide, indium tin oxide, cadmium tin oxide, antimony tin oxide, or combinations thereof.

[0071] Please see Figure 7 The reflective layer 112 is deposited on the transparent conductive layer 111. Specifically, the reflective layer 112 is a metal stack, which can be deposited in segments using methods such as metal evaporation or sputtering, forming good ohmic contact with the interfaces of each conductive plug 108. The material of the reflective layer 112 is selected from one or a combination of silver (Ag), titanium (Ti), platinum (Pt), and gold (Au) to form the reflective mirror system of the light-emitting diode. This reflective layer has high reflectivity, effectively reflecting light from inside the light-emitting diode structure to enhance luminous intensity and reduce light absorption loss within the structure.

[0072] Please see Figure 8 Next, using wafer bonding technology, the epitaxial growth substrate 100 and a conductive substrate 113 are bonded together. This conductive substrate 113 can be, but is not limited to, a silicon substrate or a sapphire substrate. Specifically, after bonding one side of the mirror layer 112 on the epitaxial growth substrate 100 to the conductive substrate 113, a wafer removal process is performed to remove the epitaxial growth substrate 100 and the intrinsic epitaxial layer 102 from one side of the conductive substrate 113, exposing the buffer epitaxial layer 103. Then, a wafer flipping process is performed, so that the conductive substrate 113 serves as the bottom support structure of the light-emitting diode chip, the first conductivity type in-situ doped epitaxial layer 104 becomes a first conductivity type in-situ doped epitaxial upper layer, and the first conductivity type in-situ doped epitaxial layer 106 becomes a first conductivity type in-situ doped epitaxial bottom layer, facilitating subsequent wafer dicing and other processes. Figure 9 As shown, a meta-electro-assay (MESA) process is performed on the epitaxial composite layer 101 to etch a portion of the epitaxial composite layer 101, specifically, the etched portion of the first conductivity type in-situ doped epitaxial upper layer, the light-emitting layer 105, and the first conductivity type in-situ doped epitaxial lower layer. Subsequently, a metal layer is formed on the buffer epitaxial layer 103, and a patterned etching process is performed on the metal layer and the buffer epitaxial layer 103 to form the upper electrode 114. Furthermore, a metal evaporation process is performed on the back side of the conductive substrate 113 to form the lower electrode 115, thus completing the final structure of the light-emitting diode of the present invention.

[0073] Please see Figure 10 The figure shows a schematic diagram of a light-emitting diode according to an embodiment of the present invention. In the epitaxial composite layer 101 shown in the figure, a first conductivity type in-situ doped epitaxial layer 106 (i.e., a first conductivity type in-situ doped epitaxial bottom layer) is disposed on a transparent conductive layer 111. More specifically, the first conductivity type in-situ doped epitaxial bottom layer has a second conductivity type local diffusion region 110 disposed on each conductive plug. When an external current is injected into the upper electrode 114, the current will flow along... Figure 10 The path A shown flows through the first conductivity type in-situ doped epitaxial layer 104 and the light-emitting layer 105, and then substantially directly flows into each conductive plug 108 through the second conductivity type local diffusion region 110, then through the reflector layer 112 and the conductive substrate 113, to the lower electrode 115. In contrast, this external current does not flow into... Figure 10 The path C shown indicates that current will not flow into the undoped diffusion region in the first conductivity in-situ doped epitaxial layer 106 (i.e., the first conductivity in-situ doped epitaxial bottom layer).

[0074] The following will be coordinated Figure 11 The electron band structure explains why, after an external current is injected from the upper electrode, the current will choose path A instead of path C. Specifically, Figure 11 The upper half of the diagram shows the built-in potential diagrams of each epitaxial layer along path A. Clearly, when an external current is applied and an external voltage is used to overcome the built-in potential of the PN diode—that is, to overcome the energy bands between the second conductivity type local diffusion region 110 (i.e., the P-type doped InP layer) and the light-emitting layer 105 (i.e., the P-type lightly doped InGaAs layer), and between the light-emitting layer 105 (i.e., the P-type lightly doped InGaAs layer) and the first conductivity type in-situ doped epitaxial layer 104 (i.e., the N-type doped InP layer)—conduction is achieved. Conversely, if the external current chooses path C, the energy band diagrams of each epitaxial layer along its path will be as follows: Figure 11 As shown in the lower part, that is, Figure 11 The PNPN junction structure shown in the lower part contains, because its energy bands include Figure 11 The reverse built-in potential between the first conductivity type in-situ doped epitaxial layer 106 (i.e., the undoped diffusion region) and the light-emitting layer 105 shown in the lower part will cause the current to be unable to conduct through path C due to the inability to conduct.

[0075] Comparing the two scenarios, when the current flows through the light-emitting layer 105 via path A, it does not overlap with the upper electrode 114 in the vertical direction. Therefore, the light generated will not be blocked by the upper electrode 114, allowing it to be emitted smoothly without being obstructed or reduced in efficiency. Conversely, if the current flows through the light-emitting layer 105 via path C, the light generated will be obstructed by the upper electrode 114, which overlaps with the light in the vertical direction, thus reducing the light extraction efficiency. In other words, the present invention, through the ingenious arrangement of the second conductive local diffusion region 110, ensures that it does not overlap with the upper electrode in the vertical direction. Furthermore, through the band structure created between the epitaxial layers, it ensures that the light-emitting diode achieves a uniform distribution within the epitaxial composite layer, significantly reducing the loss due to electrode pad obstruction, thereby greatly improving the luminous efficiency of the light-emitting diode.

[0076] On the other hand, please refer to both. Figure 10 and Figure 12 It clearly shows that there is a gap S between the peripheral region and the sidewall of the undoped diffusion region in the first conductivity type in-situ doped epitaxial layer 106, thus preventing the second conductivity type local diffusion region 110 from touching the sidewall of the epitaxial composite layer 101. According to the above embodiment, this gap S region is an N-type lightly doped indium phosphide (InP) epitaxial layer. Similarly, considering the energy band of the epitaxial layer, if an external current flows from the first conductivity type in-situ doped epitaxial layer 104, the light-emitting layer 105, through the sidewall region of the first conductivity type in-situ doped epitaxial layer 106, the second conductivity type local diffusion region 110, and then into the conductive plug 108, this path will similarly encounter the energy band structure of the PNPN junction. The reverse built-in potential between the undoped diffusion region around the first conductive in-situ doped epitaxial layer 106 and the light-emitting layer 105 will also prevent current from flowing into this sidewall region, making the peripheral region non-conductive. This avoids the problem of failure caused by ESD or EOS surge current attacks due to leakage in the peripheral region of the high-platform epitaxial layer, thus improving the anti-static capability of the light-emitting diode.

[0077] Please see Figure 4This diagram illustrates the process of manufacturing a light-emitting diode (LED) according to the present invention. First, in step S01, an epitaxial composite layer is provided on an epitaxial growth substrate. The epitaxial composite layer has a light-emitting layer and a first conductivity type in-situ doped epitaxial underlayer. In step S02, a plurality of conductive plugs are provided on the epitaxial composite layer. Next, in step S03, a second conductivity type local diffusion region is provided in the first conductivity type in-situ doped epitaxial underlayer, forming an ohmic contact with each conductive plug. In step S04, a conductive substrate is wafer-bonded to the epitaxial growth substrate, and then the epitaxial growth substrate is removed. The current flowing through the light-emitting layer substantially flows directly through the second conductivity type local diffusion region into each conductive plug and into the conductive substrate. The descriptions of the relevant components in the process steps are as described above and will not be repeated here.

[0078] In summary, the light-emitting diode of the present invention is significantly different from the traditional epitaxial structure formed solely by in-situ doping. By employing localized impurity doping and diffusion processes, the current path distribution within the light-emitting diode is controlled, preventing it from being blocked by electrode pads, thereby improving brightness and antistatic capabilities. In a preferred embodiment, the light-emitting diode of the present invention further enhances brightness by arranging the localized impurity diffusion region and the conductive plug to achieve a more uniform current distribution.

[0079] The above embodiments are merely illustrative of implementation schemes of the present invention and to explain the technical features of the present invention, and are not intended to limit the scope of protection of the present invention. Any changes or equivalent arrangements that can be easily made by those skilled in the art are within the scope of protection claimed by the present invention, and the scope of protection of the present invention should be determined by the claims.

Claims

1. A light-emitting diode, comprising: A conductive substrate; A transparent conductive layer having multiple conductive pins is disposed on the conductive substrate; and An epitaxial composite layer, comprising a light-emitting layer and a first conductivity type in-situ doped epitaxial underlayer, is disposed on the transparent conductive layer. in, The first conductivity type in-situ doped epitaxial layer has a second conductivity type local diffusion region disposed in the first conductivity type in-situ doped epitaxial layer and in contact with the conductive plug, so that the current flowing through the light-emitting layer substantially flows directly into the conductive plug through the second conductivity type local diffusion region.

2. The light-emitting diode as claimed in claim 1, wherein the first conductivity type in-situ doped epitaxial layer is an N-type indium phosphide epitaxial layer, and the second conductivity type local diffusion region is a P-type indium phosphide local diffusion region.

3. The light-emitting diode as claimed in claim 1, wherein there is a gap between the second conductivity type local diffusion region and the sidewall of the epitaxial composite layer, such that the second conductivity type local diffusion region does not touch the sidewall of the epitaxial composite layer.

4. The light-emitting diode as claimed in claim 1 further includes an upper electrode disposed on the epitaxial composite layer, wherein the upper electrode and the second conductive local diffusion region do not overlap in the vertical direction, such that the current injected from the upper electrode flows through the light-emitting layer and then substantially directly flows into the conductive plug through the second conductive local diffusion region.

5. The light-emitting diode as claimed in claim 1, wherein the light-emitting layer is an indium gallium arsenide intrinsic epitaxial layer.

6. The light-emitting diode as claimed in claim 1, wherein the light-emitting layer is a second conductivity type lightly doped indium gallium arsenide epitaxial layer.

7. The light-emitting diode as claimed in claim 1, wherein each of the conductive plugs is a second type of ohmic contact plug.

8. The light-emitting diode of claim 7, wherein the second conductive ohmic contact is a P-type indium gallium arsenide phosphide conductive contact.

9. A light-emitting diode, comprising: A conductive substrate; An epitaxial composite layer is disposed on the conductive substrate, having a light-emitting layer and a first conductivity type in-situ doped epitaxial underlayer; and An upper electrode is disposed on the epitaxial composite layer. in, The first conductivity type in-situ doped epitaxial layer has a second conductivity type local diffusion region disposed in the first conductivity type in-situ doped epitaxial layer and does not overlap with the upper electrode in the vertical direction, so that the current injected from the upper electrode flows through the light-emitting layer and substantially directly flows into the conductive substrate through the second conductivity type local diffusion region.

10. The light-emitting diode of claim 9, wherein the first conductivity type in-situ doped epitaxial layer is an N-type indium phosphide epitaxial layer, and the second conductivity type local diffusion region is a P-type indium phosphide local diffusion region.

11. The light-emitting diode of claim 9, wherein there is a gap between the second conductivity type local diffusion region and the sidewall of the epitaxial composite layer, such that the second conductivity type local diffusion region does not touch the sidewall of the epitaxial composite layer.

12. The light-emitting diode of claim 9 further comprises a transparent conductive layer having a plurality of conductive plugs disposed between the conductive substrate and the epitaxial composite layer, and forming an ohmic contact with the second conductivity type local diffusion region, such that the current injected from the upper electrode flows through the light-emitting layer and substantially directly flows into the conductive plugs through the second conductivity type local diffusion region.

13. The light-emitting diode of claim 12, wherein each of the conductive plugs is a P-type indium gallium arsenide phosphide conductive plug.

14. The light-emitting diode of claim 9, wherein the light-emitting layer is an indium gallium arsenide intrinsic epitaxial layer.

15. The light-emitting diode of claim 9, wherein the light-emitting layer is a second conductivity type lightly doped indium gallium arsenide epitaxial layer.

16. A method for manufacturing a light-emitting diode, comprising: An epitaxial composite layer is provided, disposed on an epitaxial growth substrate, having a light-emitting layer and a first conductivity type in-situ doped epitaxial underlayer. Multiple conductive pins are provided and disposed on the epitaxial composite layer; A second conductivity type local diffusion region is provided, disposed in the first conductivity type in-situ doped epitaxial layer, and forms an ohmic contact with the conductive plug; and A conductive substrate is provided and bonded to the epitaxial growth substrate via wafer bonding, after which the epitaxial growth substrate is removed. in, The current flowing through the light-emitting layer substantially flows directly into the conductive plug and into the conductive substrate through the second conductivity type local diffusion region.

17. The method of manufacturing a light-emitting diode as claimed in claim 16, wherein the step of providing a second conductive local diffusion region comprises providing a patterned mask layer disposed on the epitaxial composite layer and exposing the conductive plugs for an ion doping and diffusion process.

18. The method of manufacturing a light-emitting diode as claimed in claim 17, wherein the step of providing an ion doping and diffusion process is to have a gap between the second conductivity type local diffusion region and the sidewall of the epitaxial composite layer, and to ensure that the second conductivity type local diffusion region does not touch the sidewall of the epitaxial composite layer.

19. The method of manufacturing a light-emitting diode as claimed in claim 16, further comprising providing an upper electrode disposed on the epitaxial composite layer, wherein the upper electrode and the second conductivity type local diffusion region do not overlap in the vertical direction, such that current injected from the upper electrode flows through the light-emitting layer and substantially directly through the second conductivity type local diffusion region into the conductive plug and into the conductive substrate.

20. The method of manufacturing a light-emitting diode as claimed in claim 16, wherein the step of providing the epitaxial composite layer comprises providing a second conductivity type lightly doped indium gallium arsenide epitaxial layer as the light-emitting layer.

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