Light emitting diode

Abstract

The invention provides a light-emitting diode. The light-emitting diode comprises a substrate, a semiconductor light-emitting structure, a P-type electrode and an N-type electrode. The semiconductor light-emitting structure comprises a P-type semiconductor layer, a light-emitting layer and an N-type semiconductor layer, the P-type semiconductor layer is located on the substrate, the light-emitting layer is located on the P-type semiconductor layer, and the N-type semiconductor layer is located on the light-emitting layer; wherein the P-type semiconductor layer comprises a first side and a second side opposite to each other, the substrate is connected with the first side, and the light-emitting layer is connected with the second side; the P-type electrode is embedded into the P-type semiconductor layer from the second side of the P-type semiconductor layer to the first side of the P-type semiconductor layer, so that each side surface of the embedded part of the P-type electrode is attached to the P-type semiconductor layer; and the N-type electrode is positioned on the N-type semiconductor layer.

Description

Technical Field

[0001] This invention relates to a light-emitting diode, and more particularly to a light-emitting diode that can reduce electrode linewidth and lower resistance. Background Technology

[0002] In recent years, light-emitting diodes (LEDs) have been widely used in various fields and products with lighting needs. Currently, common LEDs mainly convert electrical energy into light energy by generating electroluminescence through the interface between two different semiconductor materials, allowing them to emit not only high-brightness light but also energy-saving properties.

[0003] Typically, red light-emitting diodes (LEDs) are constructed by sequentially stacking a P-type semiconductor layer, a light-emitting layer, an N-type semiconductor layer, and an N-type electrode on a substrate, with the P-type electrode positioned on the exposed P-type semiconductor layer. Because the P-type electrode must have sufficient linewidth and is opaque, the light-emitting area of ​​the red LED is reduced due to the P-type electrode's shielding effect, making it difficult to improve the overall brightness of the LED.

[0004] Therefore, how to design light-emitting diodes that can improve the above problems has become a topic worthy of research. Summary of the Invention

[0005] The purpose of this invention is to provide a light-emitting diode that can reduce electrode linewidth and lower resistance.

[0006] To achieve the above objectives, the light-emitting diode of the present invention includes a substrate, a semiconductor light-emitting structure, a P-type electrode, and an N-type electrode. The semiconductor light-emitting structure includes a P-type semiconductor layer, a light-emitting layer, and an N-type semiconductor layer. The P-type semiconductor layer is located on the substrate, the light-emitting layer is located on the P-type semiconductor layer, and the N-type semiconductor layer is located on the light-emitting layer. The P-type semiconductor layer includes a first side and a second side opposite to each other. The substrate is connected to the first side, and the light-emitting layer is connected to the second side. The P-type electrode is embedded in the P-type semiconductor layer from the second side toward the first side, such that each side of the embedded portion of the P-type electrode is attached to the P-type semiconductor layer. The N-type electrode is located on the N-type semiconductor layer.

[0007] In one embodiment of the present invention, the second side of the P-type semiconductor layer includes a setting region, and the setting region is an accommodating space extending from the surface of the second side toward the first side to a set depth.

[0008] In one embodiment of the present invention, the depth is set to be less than the thickness of the P-type semiconductor layer and not more than 10µm.

[0009] In one embodiment of the present invention, the setting area is kept at a distance from the light-emitting layer and the N-type semiconductor layer of the semiconductor light-emitting structure in the horizontal direction.

[0010] In one embodiment of the present invention, the P-type semiconductor layer is made of P-type gallium phosphide material, and the N-type semiconductor layer is made of N-type aluminum gallium indium phosphide material.

[0011] In one embodiment of the present invention, the cross-sectional area of ​​the P-type electrode in the horizontal direction is not less than 3% of the total cross-sectional area of ​​the light-emitting diode in the horizontal direction.

[0012] In one embodiment of the present invention, the set wavelength of the semiconductor light-emitting structure is between 590 nm and 1050 nm.

[0013] In one embodiment of the present invention, the light-emitting diode further includes a bonding layer located between the substrate and the first semiconductor layer, wherein the bonding layer is made of silicon dioxide material.

[0014] In one embodiment of the present invention, the P-type electrode is made of beryllium gold alloy or zinc gold alloy.

[0015] In one embodiment of the present invention, the substrate is a sapphire substrate.

[0016] With this design, the light-emitting diode of the present invention increases the contact area between the P-type electrode and the P-type semiconductor layer by embedding the P-type electrode in the P-type semiconductor layer, thereby reducing the resistance of the P-type electrode. In circuit design, the linewidth of the P-type electrode can be reduced, thereby increasing the light-emitting area and improving the overall brightness of the light-emitting diode. Attached Figure Description

[0017] Figure 1 This is a top view of the light-emitting diode of the present invention.

[0018] Figure 2 The light-emitting diode of the present invention is along Figure 1 A cross-sectional view of line segment AA in the diagram.

[0019] Figure 3 This is a schematic diagram of the manufacturing process of the light-emitting diode of the present invention. Detailed Implementation

[0020] Since the various aspects and embodiments are merely illustrative and non-limiting, other aspects and embodiments may arise for those skilled in the art after reading this specification without departing from the scope of the invention. The features and advantages of these embodiments will become more apparent from the following detailed description and the scope of this application.

[0021] In this document, the terms "a" or "an (species / component)" are used to describe the elements and components described herein. This is done for ease of explanation only and to provide a general meaning regarding the scope of the invention. Therefore, unless it is clearly intended otherwise, this description should be understood to include one (species / component) or at least one (species / component), and the singular also includes multiples.

[0022] In this document, ordinal numbers such as "first" or "second" are primarily used to distinguish or refer to identical or similar elements or structures, and do not necessarily imply a spatial or temporal order of these elements or structures. It should be understood that, in certain situations or configurations, ordinal numbers can be used interchangeably without affecting the implementation of this application.

[0023] In this document, the terms “comprising,” “having,” or any other similar terms are intended to cover non-exclusive inclusions. For example, an element or structure containing multiple elements is not limited to those listed herein, but may include other elements not expressly listed but which are generally inherent to the element or structure.

[0024] Reference Figure 1 and Figure 2 ,in Figure 1 This is a top view of the light-emitting diode of the present invention. Figure 2 The light-emitting diode of the present invention is along Figure 1 A cross-sectional view of line segment AA in the diagram. (See diagram below.) Figure 1 and Figure 2 As shown, the light-emitting diode 1 of the present invention mainly includes a substrate 10, a semiconductor light-emitting structure 20, a P-type electrode 30, and an N-type electrode 40. The substrate 10 is the basic structural component of the light-emitting diode 1 of the present invention, used to support the semiconductor light-emitting structure 20, the P-type electrode 30, the N-type electrode 40, and other components. In the present invention, the substrate 10 is made of single-polished sapphire material, but the substrate 10 can also be made of other common substrate materials.

[0025] A semiconductor light-emitting structure 20 is located on a substrate 10 and is used to emit light with a set wavelength after becoming conductive. The semiconductor light-emitting structure 20 is an epitaxial stacked structure and includes a P-type semiconductor layer 21, a light-emitting layer 22, and an N-type semiconductor layer 23. The P-type semiconductor layer 21 is located on the substrate 10, the light-emitting layer 22 is located on the P-type semiconductor layer 21, and the N-type semiconductor layer 23 is located on the light-emitting layer 22. In one embodiment of the present invention, the P-type semiconductor layer 21 is made of P-type gallium phosphide (P-GaP) material, the light-emitting layer 22 is a multiple-quantum-well (MQW) layer, and the N-type semiconductor layer 23 is made of N-type aluminum gallium indium phosphide (N-AlGaInP) material. Accordingly, the semiconductor light-emitting structure 20 can exhibit a P-MQW-N epitaxial stacked structure.

[0026] The P-type semiconductor layer 21 mainly includes a first side 211 and a second side 212 facing each other. The first side 211 faces and is close to the substrate 10, while the second side 212 faces away from and is far from the substrate 10. The P-type semiconductor layer 21 is connected to the substrate 10 through the first side 211, and the P-type semiconductor layer 21 is connected to the light-emitting layer 23 and the P-type electrode 30 through the second side 212. In this invention, the P-type electrode 30 is embedded in the P-type semiconductor layer 21 from the second side 212 toward the first side 211 (or the substrate 10), such that each side of the embedded portion of the P-type electrode 30 (e.g., the lower surface and side surface of the embedded portion) adheres to the P-type semiconductor layer 21, thereby increasing the contact area between the P-type electrode 30 and the P-type semiconductor layer 21.

[0027] Further, in one embodiment of the present invention, the second side 212 of the P-type semiconductor layer 21 includes a placement area B. The placement area B is an accommodating space extending from the surface of the second side 212 toward the first side 211 to a predetermined depth D, where a P-type electrode 30 can be disposed such that the P-type electrode 30 is at least partially buried within the P-type semiconductor layer 21. In one embodiment of the present invention, the predetermined depth D is less than the thickness of the P-type semiconductor layer 21, and the predetermined depth D does not exceed 10µm. Structurally, the placement area B maintains a horizontal distance from the light-emitting layer 22 and the N-type semiconductor layer 23 of the aforementioned formed semiconductor light-emitting structure 20, without direct contact.

[0028] Accordingly, by embedding a portion of the P-type electrode 30 into the P-type semiconductor layer 21, the contact area between the P-type electrode 30 and the P-type semiconductor layer 21 can be effectively increased, thereby reducing the resistance. This eliminates the need to increase the original design linewidth of the P-type electrode 30, and can even further reduce the design linewidth to shrink the electrode area, thereby increasing the light-emitting area. Furthermore, in one embodiment of the present invention, the P-type electrode 30 is made of beryllium gold (BeAu) alloy or zinc gold (ZnAu) alloy, but the present invention is not limited thereto.

[0029] In terms of design, the area occupied by the P-type electrode 30 of the light-emitting diode 1 of the present invention is subject to specific limitations compared to the die area of ​​the light-emitting diode 1 of the present invention. To prevent the die voltage of the light-emitting diode 1 of the present invention from being too high, in one embodiment of the present invention, the cross-sectional area of ​​the P-type electrode 30 along the horizontal direction (i.e., corresponding to...) Figure 1 The area of ​​setting area B in the image is not less than the total cross-sectional area of ​​LED 1 along the horizontal direction (i.e., the corresponding area of ​​setting area B in the image). Figure 1 and Figure 2The cross-sectional area of ​​the P-type semiconductor layer 21 in the horizontal direction is 3% to provide a voltage stabilizing effect; preferably, in one embodiment of the invention, the cross-sectional area of ​​the P-type electrode 30 in the horizontal direction is about 3% to 20% of the total cross-sectional area of ​​the light-emitting diode 1 in the horizontal direction.

[0030] The N-type electrode 40 is located on the N-type semiconductor layer 23. In one embodiment of the invention, the N-type electrode 40 is made of a common metal, such as gold (Au), nickel (Ni), or germanium (Ge), but other metals or alloys may also be used.

[0031] The light emitted by the aforementioned semiconductor light-emitting structure 20 has a set wavelength, which varies depending on the material used in the semiconductor light-emitting structure 20. In one embodiment of the present invention, the set wavelength of the semiconductor light-emitting structure 20 is between 590 nm and 1050 nm, that is, the semiconductor light-emitting structure 20 of the light-emitting diode 1 of the present invention emits light corresponding to the red light band.

[0032] Furthermore, in one embodiment of the present invention, the light-emitting diode 1 further includes a bonding layer 50. The bonding layer 50 is located between the substrate 10 and the P-type semiconductor layer 21 of the semiconductor light-emitting structure 20. The bonding layer 50 is made of silicon dioxide (SiO2) material. The bonding layer 50 can provide a better interface bonding effect between the substrate 10 and the semiconductor light-emitting structure 20. However, the present invention is not limited to this, and the bonding layer 50 can also be made of other materials that can provide similar effects.

[0033] The following describes the manufacturing process of the light-emitting diode 1 of the present invention. Please refer to [link / reference needed]. Figure 3 This is a schematic diagram illustrating the manufacturing process of the light-emitting diode of the present invention. (As shown...) Figure 3 As shown, a gallium arsenide (GaAs) substrate is first provided as the epitaxial substrate, and a semiconductor epitaxial process is performed on the GaAs substrate to form a semiconductor light-emitting structure 20 including the aforementioned P-type semiconductor layer 21, light-emitting layer 22, and N-type semiconductor layer 23. Next, a surface roughening process is performed on the exposed side of the P-type semiconductor layer 21, and a bonding layer 50 is formed on the roughened exposed side to bond the substrate 10 to the semiconductor light-emitting structure 20 via the bonding layer 50. After the substrate 10 and the semiconductor light-emitting structure 20 are bonded, the gallium arsenide substrate can be removed, revealing the structure as shown. Figure 3 The structure in (a) is shown. Then, a platform (MESA) process is performed on the semiconductor light-emitting structure 20, such that a planar region for forming the setting region B is formed on the second side 212 of the P-type semiconductor layer 21, and the structure exhibits the following characteristics: Figure 3 The structure of (b).

[0034] After performing the platform process, photolithography and dry (or wet) etching processes are then performed on the semiconductor light-emitting structure 20 to form a setting region B with a set depth on the second side 212 of the P-type semiconductor layer 21, and to present a shape as shown in the image. Figure 3 The structure in (c) is then combined with photolithography and vapor deposition processes to form a P-type electrode 30 buried at a set depth within the setting region B of the P-type semiconductor layer 21, and exhibiting the appearance of... Figure 3 The structure is shown in (d). Finally, a similar photolithography and vapor deposition process is performed to form an N-type electrode 40 on the N-type semiconductor layer 23, exhibiting the structure shown in (d). Figure 1 and Figure 2 The light-emitting diode 1 in the present invention is then used to complete the relevant manufacturing process of the light-emitting diode 1 of the present invention.

[0035] With this design, the light-emitting diode of the present invention increases the contact area between the P-type electrode and the P-type semiconductor layer by embedding the P-type electrode in the P-type semiconductor layer, thereby reducing the resistance of the P-type electrode. In circuit design, the linewidth of the P-type electrode can be reduced, thereby increasing the light-emitting area and improving the overall brightness of the light-emitting diode.

[0036] The above embodiments are merely illustrative in nature and are not intended to limit the embodiments of the subject matter of the application or the application or use of such embodiments. Furthermore, although at least one exemplary embodiment has been presented in the foregoing embodiments, it should be understood that numerous variations are possible with respect to the invention. It should also be understood that the embodiments described herein are not intended to limit the scope, use, or configuration of the claimed subject matter in any way. Rather, the foregoing embodiments will provide a simple guide for those skilled in the art to implement one or more of the described embodiments. Moreover, various changes can be made to the function and arrangement of the elements without departing from the scope defined by the claims, which include known equivalents and all foreseeable equivalents at the time of filing of this patent application.

[0037] [Symbol Explanation] 1 LED 10 substrates 20 Semiconductor Light Emitting Structure 21P type semiconductor layer 211 First Side 212 Second side 22 light-emitting layers 23N type semiconductor layer 30P type electrode 40N type electrode 50 bonded layers B Setting Area D sets the depth

Claims

1. A light emitting diode, comprising: a substrate; a semiconductor light emitting structure comprising a P-type semiconductor layer, a light emitting layer, and an N-type semiconductor layer, the P-type semiconductor layer being on the substrate, the light emitting layer being on the P-type semiconductor layer, and the N-type semiconductor layer being on the light emitting layer; wherein the P-type semiconductor layer comprises a first side and a second side opposite to each other, the substrate is connected to the first side, and the light emitting layer is connected to the second side; a P-type electrode embedded into the P-type semiconductor layer from the second side toward the first side of the P-type semiconductor layer, such that each side surface of the embedded portion of the P-type electrode is in contact with the P-type semiconductor layer; and an N-type electrode on the N-type semiconductor layer.

2. The light emitting diode of claim 1, wherein, The second side of the P-type semiconductor layer comprises a setting region, and the setting region is a receiving space extending to a set depth from a surface of the second side toward the first side.

3. The light emitting diode of claim 2, wherein, The set depth is less than the thickness of the P-type semiconductor layer and does not exceed 10 µm.

4. The light emitting diode of claim 2, wherein, The setting region is spaced apart from the light emitting layer and the N-type semiconductor layer of the semiconductor light emitting structure in a horizontal direction.

5. The light emitting diode of claim 1, wherein, The P-type semiconductor layer is made of a P-type gallium phosphide material, and the N-type semiconductor layer is made of an N-type aluminum gallium indium phosphide material.

6. The light emitting diode of claim 1, wherein, A cross-sectional area of the P-type electrode in a horizontal direction is not less than 3% of a total cross-sectional area of the light emitting diode in the horizontal direction.

7. The light emitting diode of claim 1, wherein, A set wavelength of the semiconductor light emitting structure is between 590 nm and 1050 nm.

8. The light emitting diode of claim 1, further comprising a bonding layer between the substrate and the P-type semiconductor layer, wherein, The bonding layer is made of a silicon dioxide material.

9. The light emitting diode of claim 1, wherein, The P-type electrode is made of a beryllium-gold alloy material or a zinc-gold alloy material.

10. The light emitting diode of claim 1, wherein, The substrate is a sapphire substrate.

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