Light emitting diode and light emitting device

Abstract

This invention relates to the field of semiconductor manufacturing technology, and particularly to a light-emitting diode (LED), comprising a semiconductor stack and a first electrode. The semiconductor stack includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked sequentially. The surface of the first semiconductor layer has a roughened structure, and the first electrode is disposed on the surface of the first semiconductor layer, wherein the first electrode at least partially covers the roughened structure. This configuration effectively improves the current spreading performance of the LED and enhances its quality.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a light-emitting diode and a light-emitting device. Background Technology

[0002] A light-emitting diode (LED) is a semiconductor light-emitting element, typically made of semiconductors such as GaN, GaAs, GaP, and GaAsP. Its core is a PN junction that emits light. LEDs possess advantages such as high luminous intensity, high efficiency, small size, and long lifespan, and are considered one of the most promising light sources available today. LEDs are widely used in lighting, monitoring and command systems, high-definition broadcasting, high-end cinemas, office displays, interactive conferencing, virtual reality, and other fields.

[0003] In recent years, with the advancement of GaN material preparation technology, GaN-based LEDs have been gradually applied to various aspects of life. However, in some mid-to-high-end applications, the performance requirements for LEDs are becoming increasingly stringent, with high luminous efficiency, low energy consumption, and high reliability becoming the common goals of all LED product developers. Currently, LEDs commonly exhibit uneven current distribution under high-current applications, leading to increased junction temperature and severe degradation of luminous efficiency. Therefore, improving the current distribution capability of LEDs has become a pressing problem and challenge for those skilled in the art.

[0004] It should be noted that the information disclosed in this background section is intended only to enhance the understanding of the overall background of the present invention, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] This invention provides a light-emitting diode (LED) comprising a semiconductor stack and a first electrode. The semiconductor stack includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked sequentially, wherein the surface of the first semiconductor layer has a roughened structure. The first electrode is disposed on the surface of the first semiconductor layer. The first electrode at least partially covers the roughened structure.

[0006] The present invention also provides a light-emitting device, which includes a circuit board and a light-emitting diode, wherein the light-emitting diode is disposed on the circuit board, and the light-emitting diode is the light-emitting diode provided in any of the above embodiments.

[0007] An embodiment of the present invention provides a light-emitting diode and a light-emitting device. By covering a roughened structure with a first electrode, a portion of the first electrode is directly deposited onto the roughened structure during the evaporation process, thereby forming a relatively low contact barrier in that area. Therefore, spatially, the contact area between the first electrode and the first semiconductor layer forms a high contact barrier region and a low contact barrier region. Current tends to diffuse through the low contact barrier region to the light-emitting region, thus effectively improving the current diffusion performance of the light-emitting diode and enhancing its quality.

[0008] Other features and advantages of the present invention will be set forth in the following description, and some of the technical features and advantages may be apparent from the description or learned by practicing the invention. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, some of the drawings in the following description are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a top view schematic diagram of the structure of a light-emitting diode provided in an embodiment of the present invention;

[0011] Figure 2A It is along Figure 1 A schematic diagram of the cross-sectional structure intercepted by the intercept line FF;

[0012] Figure 2B yes Figure 2A A magnified view of point A in the diagram;

[0013] Figure 2C yes Figure 2B A schematic diagram of the vertical projection of the lower end point of the edge of the corresponding first electrode and the roughened structure onto the horizontal plane;

[0014] Figure 3 This is a schematic diagram of the structure of the first electrode and the first semiconductor layer provided in an embodiment of the present invention;

[0015] Figure 4 This is a top view schematic diagram of the first electrode and semiconductor stack provided in an embodiment of the present invention;

[0016] Figure 5 This is a schematic diagram of the structure of a light-emitting diode provided in another embodiment of the present invention;

[0017] Figure 6This is a schematic diagram of a horizontally structured light-emitting diode provided in another embodiment of the present invention;

[0018] Figure 7 This is a top view of the structure of a light-emitting diode provided in another embodiment of the present invention;

[0019] Figure 8 yes Figure 7 A schematic diagram of the cross-sectional structure taken from the middle;

[0020] Figure 9 This is a top view of the structure of a light-emitting diode provided in another embodiment of the present invention;

[0021] Figure 10 yes Figure 9 A schematic diagram of the cross-sectional structure taken from the middle.

[0022] Figure label:

[0023] 10-Semiconductor stack; 101-First semiconductor layer; 102-Light-emitting layer; 103-Second semiconductor layer; 11-Roughened structure; 12-First electrode; 121-Electrode extension; 122-Blocking electrode; 14-Second electrode; 16-Insulating layer; 18-Current blocking layer; 20-Bonding layer; 22-Substrate; 24-Back metal layer; C1, C2-Lower edge endpoints; 31-First sidewall; 32-Second sidewall; 33-Outer sidewall; 41-Side region; 42-Central region; 52-Transparent conductive layer; 54-Metal reflective layer; L1, L2-Distance; S1, S2-Vertical projection line segments. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. The technical features designed in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be understood that the terms "center," "lateral," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. Additionally, the term "comprising" and any variations thereof mean "at least comprising."

[0026] This invention provides a light-emitting diode (LED) comprising a semiconductor stack and a first electrode. The semiconductor stack includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked sequentially. The surface of the first semiconductor layer has a roughened structure. The first electrode is disposed on the surface of the first semiconductor layer. The first electrode at least partially covers the roughened structure. By covering the roughened structure with the first electrode, a portion of the first electrode is directly deposited onto the roughened structure during the evaporation process, thereby forming a relatively low contact barrier in this area. Therefore, spatially, the contact area between the first electrode and the first semiconductor layer forms a high contact barrier region and a low contact barrier region. Current tends to diffuse through the low contact barrier region to the light-emitting region, thus effectively improving the current diffusion performance of the LED and enhancing its quality.

[0027] In some embodiments, the vertical projection points of at least one lower edge of the first electrode onto the horizontal plane are distributed within the vertical projection line segment of the roughened structure onto the horizontal plane. That is, the low barrier contact region formed between the first electrode and the first semiconductor layer is located on the side of the first electrode, thereby allowing more current to flow downward through the side region of the first electrode, preventing current from being directly injected downward from the electrode, and improving the current spreading performance of the light-emitting diode.

[0028] In some embodiments, the first electrode includes at least one electrode extension having opposing first and second sidewalls. The roughened structure covered by the electrode extension extends from the first sidewall toward the second sidewall by a distance of 0.1 to 10 micrometers, such that the low contact barrier region formed between the roughened structure and the first electrode is kept at an appropriate size, effectively improving the current spreading performance of the light-emitting diode.

[0029] In some embodiments, the first electrode includes at least one electrode extension having opposing first and second sidewalls. The ratio of the distance the roughened structure covered by the electrode extension extends from the first sidewall to the second sidewall to the distance between the first and second sidewalls is no greater than 1 / 3, so that the low contact barrier region formed between the roughened structure and the first electrode is kept at an appropriate size, effectively improving the current spreading performance of the light-emitting diode.

[0030] In some embodiments, the distance by which the roughened structure covered by the electrode extension extends from the first sidewall to the second sidewall is greater than or equal to the distance by which the roughened structure covered by the electrode extension extends from the second sidewall to the first sidewall. This is because the electrode extension closer to the center of the LED covers more roughened structures, while the electrode extension closer to the outer edge of the LED covers less roughened structures, thus further improving the current spreading performance of the LED.

[0031] In some embodiments, the roughened structure covered by the electrode extension extends from the second sidewall to the first sidewall by a distance of 0 to 10 micrometers, such that the electrode extension is less covered by the roughened structure closer to the outer edge of the light-emitting diode.

[0032] In some embodiments, considering that no current needs to diffuse to the edge of the LED, the second sidewall is closer to the edge of the LED than the first sidewall.

[0033] In some embodiments, the first electrode includes a block electrode having a peripheral sidewall. The roughened structure covered by the block electrode extends from the peripheral sidewall toward the center of the block electrode by a distance of 0.1 to 15 micrometers, so that the low contact barrier region formed between the roughened structure and the first electrode is kept at an appropriate size, effectively improving the current spreading performance of the light-emitting diode.

[0034] In some embodiments, the first electrode includes a block electrode having a peripheral sidewall. The roughened structure covered by the block electrode extends from the peripheral sidewall toward the center of the block electrode at a distance that is no more than 1 / 3 of the size of the block electrode. This ensures that the low contact barrier region formed between the roughened structure and the first electrode is kept at an appropriate size, effectively improving the current spreading performance of the light-emitting diode.

[0035] In some embodiments, the first electrode has opposing inner and outer sidewalls, and the distance by which the roughened structure covered by the first electrode extends from the inner sidewall to the outer sidewall is greater than or equal to the distance by which the roughened structure covered by the first electrode extends from the outer sidewall to the inner sidewall. This is because the first electrode closer to the center of the LED has more roughened structure covered, and the first electrode closer to the outer edge of the LED has less roughened structure covered, which can further improve the current spreading performance of the LED.

[0036] In some embodiments, considering that no current needs to diffuse to the edge of the LED, the outer wall is closer to the edge of the LED than the inner wall.

[0037] In some embodiments, the first electrode includes a side region and a central region, the side region being connected to the central region, the side region being covered by a roughened structure, and the central region not being covered by the roughened structure. That is, the low-barrier contact region formed between the first electrode and the first semiconductor layer is located at the side of the first electrode, thereby allowing more current to flow downward through the side region of the first electrode, preventing current from being directly injected downward from the electrode, and improving the current spreading performance of the light-emitting diode.

[0038] In some embodiments, from the perspective of the longitudinal cross-section of the light-emitting diode, the side region refers to the region formed by extending from the sidewall of the first electrode toward the center of the first electrode. The sum of the lengths of the vertical projection line segments of the side region on the horizontal plane is defined as the first length, and the sum of the lengths of the vertical projection line segments of the center region on the horizontal plane is defined as the second length. The ratio of the first length to the second length is not greater than 2, so that the low contact barrier region formed between the roughened structure and the first electrode is kept at an appropriate size, effectively improving the current spreading performance of the light-emitting diode.

[0039] In some embodiments, the area ratio of the side region to the center region is no greater than 2, so that the low contact barrier region formed between the roughened structure and the first electrode is kept at an appropriate size, effectively improving the current spreading performance of the light-emitting diode.

[0040] In some embodiments, the area ratio of the side region to the first electrode is no greater than 2 / 3, so that the low contact barrier region formed between the roughened structure and the first electrode is kept at an appropriate size, effectively improving the current spreading performance of the light-emitting diode.

[0041] In some embodiments, the light-emitting diode further includes a second electrode disposed on the lower surface of the second semiconductor layer.

[0042] In some embodiments, the light-emitting diode further includes an insulating layer, a current blocking layer, a bonding layer, a substrate, and a back metal layer. The insulating layer covers the semiconductor stack, the current blocking layer is disposed on the lower surface of the second semiconductor layer and connected to the second electrode, the bonding layer is disposed on the lower surface of the second electrode, the substrate is disposed on the lower surface of the bonding layer, and the back metal layer is disposed on the lower surface of the substrate.

[0043] In some embodiments, the roughness of the roughened structure is 0.2 to 1 μm.

[0044] In some embodiments, the light-emitting diode is a vertically oriented light-emitting diode.

[0045] In some embodiments, the current density of the light-emitting diode is ≥1A / mm². 2 The light-emitting diode described in this invention operates at a current density greater than or equal to 1 A / mm². 2 It performs better in high current density scenarios.

[0046] The present invention also provides a light-emitting device, which includes a circuit board and a light-emitting diode, wherein the light-emitting diode is disposed on the circuit board, and the light-emitting diode is the light-emitting diode provided in any of the above embodiments.

[0047] Please see Figures 1 to 3 , Figure 1 This is a top view schematic diagram of a light-emitting diode provided in an embodiment of the present invention. Figure 2A It is along Figure 1 A schematic diagram of the cross-sectional structure intercepted by the intercept line FF. Figure 2B yes Figure 2A A magnified view of a portion of point A in the diagram. Figure 2C yes Figure 2B A schematic diagram of the vertical projection of the lower end point M of the edge of the first electrode 12 and the roughened structure 11 onto the horizontal plane. Figure 3 This is a schematic diagram of the structure of the first electrode 12 and the first semiconductor layer 101 provided in an embodiment of the present invention. To achieve at least one or more of the aforementioned advantages, an embodiment of the present invention provides a light-emitting diode. As shown in the figure, the light-emitting diode includes a semiconductor stack 10 and a first electrode 12.

[0048] The semiconductor stack 10 includes a first semiconductor layer 101, a light-emitting layer 102, and a second semiconductor layer 103 stacked sequentially. That is, the light-emitting layer 102 is located between the first semiconductor layer 101 and the second semiconductor layer 103.

[0049] The first semiconductor layer 101 can be an N-type semiconductor layer, which can provide electrons to the light-emitting layer 102 under the action of a power source. In some embodiments, the first semiconductor layer 101 includes an N-type doped nitride layer. The N-type impurity can include one or a combination of Si, Ge, and Sn. The material of the first semiconductor layer 101 can include GaN, AlGaN, InGaN, InAlGaN, etc., or materials including AlGaAs, GaP, GaAs, GaAsP, AlGaInP, etc. Currently, in order to improve the emission efficiency of light emitted from the light-emitting layer 102, the surface of the first semiconductor layer 101 is roughened, that is, the surface of the first semiconductor layer 101 has a roughened structure 11. Optionally, the roughness of the roughened structure 11 is 0.2 to 1 μm.

[0050] The light-emitting layer 102 can be a quantum well (QW) structure. In some embodiments, the light-emitting layer 102 can also be a multiple quantum well (MQW) structure, wherein the multiple quantum well structure includes multiple quantum well layers (Wells) and multiple quantum barrier layers (Barriers) arranged alternately in a repeating manner, such as a GaN / AlGaN, InAlGaN / InAlGaN, or InGaN / AlGaN multi-quantum well structure. Furthermore, the composition and thickness of the well layers within the light-emitting layer 102 determine the wavelength of the generated light. To improve the luminous efficiency of the light-emitting layer 102, this can be achieved by changing the depth of the quantum wells, the number of paired quantum wells and quantum barriers, the thickness, and / or other characteristics within the light-emitting layer 102.

[0051] The second semiconductor layer 103 can be a P-type semiconductor layer, which can provide holes to the light-emitting layer 102 under power. In some embodiments, the second semiconductor layer 103 includes a P-type doped nitride layer. The P-type impurity can include one or a combination of Mg, Zn, and Be. The second semiconductor layer 103 can be a single-layer structure or a multi-layer structure with different compositions. The light-emitting diode can be a vertically oriented light-emitting diode, a conventionally oriented light-emitting diode, or a flip-chip light-emitting diode.

[0052] The first electrode 12 is disposed on the surface of the first semiconductor layer 101. Figure 1The location of the first electrode 12 is indicated by shading. The first electrode 12 can be a single-layer, double-layer, or multi-layer structure, such as Ti / Al, Ti / Al / Ti / Au, Ti / Al / Ni / Au, V / Al / Pt / Au, etc. During the fabrication process, taking the first semiconductor of GaN material as an example, the roughened structure 11 formed by the roughening treatment of the GaN first semiconductor layer 101 surface is corroded by a strong alkaline solution, such as KOH. Therefore, the free atoms or dielectric oxides on the surface of the GaN first semiconductor layer 101 in this region are effectively removed, that is, the Ga atoms or GaOx on the surface of the GaN material are removed. Then, through Ar plasma treatment before the first electrode 12 is deposited, the nitrogen vacancies on the surface of the first semiconductor in this region can be increased simultaneously, thereby reducing the contact barrier in this region. Therefore, the contact area between the first electrode 12 and the first semiconductor layer 101 forms a high contact barrier region and a low contact barrier region. In other words, the area where the first electrode 12 contacts the roughened structure 11 forms a low contact barrier region, while the area where the first electrode 12 contacts the unroughened surface of the first semiconductor layer 101 forms a high contact barrier region. Current tends to diffuse through the low contact barrier region to the light-emitting region. Therefore, by providing at least a portion of the roughened structure 11 covered by the first electrode 12, both high and low contact barrier regions are formed, effectively improving the current diffusion performance of the light-emitting diode and enhancing its quality.

[0053] In some embodiments, the vertical projection points of at least one lower edge endpoint M of the first electrode 12 in the horizontal plane are distributed within the vertical projection line segment S1 of the roughened structure 11 in the horizontal plane. This vertical projection line segment S1 can be a single line segment or composed of multiple spaced line segments, and the projection point of the lower edge endpoint M is located only within one of these multiple line segments. That is, the low-barrier contact region formed between the first electrode 12 and the first semiconductor layer 101 is located on the side of the first electrode 12, allowing more current to flow downwards through the side region of the first electrode 12, preventing current from being directly injected downwards from the electrode, and improving the current spreading performance of the light-emitting diode. Optionally, in high-current applications (such as light-emitting diode current density ≥ 1 A / mm²), 2 For LEDs, the current spreading requirements are higher. Therefore, the vertical projection points of the two lower edge endpoints M and N of the first electrode 12 onto the horizontal plane can be distributed within the vertical projection lines S1 and S2 of the roughened structure 11 onto the horizontal plane. This means that low-barrier contact areas are formed on both the left and right sides of the first electrode 12, resulting in better current spreading. In this embodiment, the sidewall is a vertical sidewall. In some embodiments, when the sidewall is an inclined sidewall, the lower edge endpoint M is determined by the outermost intersection point of the first electrode 12 and the surface of the first semiconductor layer 101 in the longitudinal section of the LED.

[0054] In some embodiments, the first electrode 12 includes at least one electrode extension 121. The first electrode 12 may also include a pad electrode (e.g., Figure 1 The two areas (lower left and lower right) contain pad electrodes primarily used for external wire bonding during packaging. The pad electrodes can be designed in different shapes according to actual wire bonding needs, such as cylindrical, square, or other polygonal shapes. The electrode extension 121 can be formed in a predetermined pattern shape, and the electrode extension 121 can have various shapes; in this embodiment, for example... Figure 1 As shown, the electrode extension 121 is strip-shaped and has 5 longitudinal electrode extensions 121 and 2 transverse electrode extensions 121.

[0055] The electrode extension 121 has opposing first sidewalls 31 and second sidewalls 32, such as Figure 2B The left and right sidewalls are shown. Considering that the low contact barrier region formed between the roughened structure 11 and the first electrode 12 should be kept at an appropriate size to effectively improve the current spreading performance of the light-emitting diode, optionally, the roughened structure 11 covered by the electrode extension 121 extends from the first sidewall 31 towards the second sidewall 32 a distance L1 of 0.1 to 10 micrometers. Preferably, in some embodiments, L1 can be 1 to 6 micrometers, for example, 2 micrometers, 3 micrometers, 4 micrometers, or 5 micrometers. Optionally, the ratio of the distance L1 extending from the first sidewall 31 towards the second sidewall 32 to the distance between the first sidewall 31 and the second sidewall 32 is not greater than 1 / 3. The above definition of the sidewall is based on the longitudinal section of the light-emitting diode. The extension direction can be horizontal. The sidewalls shown in the figure are vertical sidewalls, with the starting point being the lowest endpoint of each sidewall, such as points M and N in the figure. When the sidewall is an inclined sidewall, starting from the first sidewall 31 refers to the lowest point of the first sidewall 31 in the inclined state. Similarly, starting from the second sidewall 32 refers to the lowest point of the second sidewall 32 in the inclined state.

[0056] In some embodiments, considering that the electrode extension 121 closer to the center of the LED covers more of the roughened structure 11, and the electrode extension 121 closer to the outer edge of the LED covers less of the roughened structure 11, the current spreading performance of the LED can be further improved. Therefore, the distance L1 of the roughened structure 11 covered by the electrode extension 121 extending from the first sidewall 31 to the second sidewall 32 can be greater than or equal to the distance L2 of the roughened structure 11 covered by the electrode extension 121 extending from the second sidewall 32 to the first sidewall 31. In some embodiments, considering that current diffusion to the edge of the LED is not required closer to the edge of the LED, the second sidewall 32 is closer to the edge of the LED than the first sidewall 31. The roughened structure 11 covered by the electrode extension 121 extends from the second sidewall 32 towards the first sidewall 31 for a distance L2 of 0 to 10 micrometers, such that the roughened structure 11 covered by the electrode extension 121 is less near the outer edge of the light-emitting diode. Preferably, in some embodiments, L1 can be 1 to 6 micrometers, for example, 2 micrometers, 3 micrometers, 4 micrometers, or 5 micrometers. In some embodiments, the roughened structure 11 may not be covered below the second sidewall 32 of the electrode extension 121.

[0057] In some embodiments, the first electrode 12 is defined to have opposing inner and outer sidewalls, with the outer sidewall being closer to the edge of the light-emitting diode than the inner sidewall. Figure 1 Taking an example, looking from left to right, the left sidewall of the first electrode extension 121 is the outer sidewall, and the right sidewall of the first electrode extension 121 is the inner sidewall; or, the right sidewall of the first electrode extension 121 is the outer sidewall, and the left sidewall of the second electrode extension 121 is the inner sidewall; or, the right sidewall of the first electrode extension 121 is the inner sidewall, and the right sidewall of the fifth electrode extension 121 is the outer sidewall. In other words, the outer and inner sidewalls are determined relative to each other; the sidewall closer to the center of the LED is the inner sidewall, and the other is the outer sidewall. Considering that the first electrode 12 closer to the center of the LED is covered by more roughened structures 11, and the first electrode 12 closer to the outer edge of the LED is covered by less roughened structures 11, the current spreading performance of the LED can be further improved. Therefore, the distance that the roughened structure 11 covered by the first electrode 12 extends from the inner wall to the outer wall is greater than or equal to the distance that the roughened structure covered by the first electrode extends from the outer wall to the inner wall.

[0058] In some embodiments, such as Figure 3 As shown, the first electrode 12 includes a side region 41 and a central region 42. Figure 3The side region 41 and the central region 42 are illustrated using different shading patterns. The side region 41 connects to the central region 42. The side region 41 covers the roughened structure 11, while the central region 42 does not cover the roughened structure 11. That is, the side region 41 refers to the portion of the first electrode 12 above the roughened structure 11, and the central region 42 refers to the portion of the first electrode 12 not above the roughened structure 11. Considering that the low contact barrier region formed between the roughened structure 11 and the first electrode 12 should be kept at an appropriate size to effectively improve the current spreading performance of the light-emitting diode, optionally, from the longitudinal cross-sectional view of the light-emitting diode, the side region 41 refers to the region formed by extending from the sidewall of the first electrode 12 towards the center of the first electrode 12. The sum of the lengths of the vertical projection line segments of the side region 41 on the horizontal plane is defined as the first length (the sum of W1 and W2 in the figure), and the sum of the lengths of the vertical projection line segments of the central region 42 on the horizontal plane is defined as the second length (W3 in the figure). The ratio of the first length to the second length is not greater than 2. Optionally, from the perspective of the longitudinal section of the light-emitting diode, refer to Figure 3 As shown, the area ratio of the side region 41 to the central region 42 is no greater than 2; optionally, the area ratio of the side region 41 to the first electrode 12 is no greater than 2 / 3.

[0059] In some embodiments, such as Figure 4 As shown in the figure, only the relative positional relationship between the first electrode 12 and the semiconductor stack 10 is illustrated. The first electrode 12 includes a block electrode 122, the shape of which differs from the electrode extension 121. It is primarily a single, integral block, such as a near-circular or square shape. The block electrode 122 has a peripheral sidewall 33. Considering that the low contact barrier region formed between the roughened structure 11 and the first electrode 12 should be kept at an appropriate size to effectively improve the current spreading performance of the light-emitting diode, the roughened structure 11 covered by the block electrode 122 extends from the peripheral sidewall 33 towards the center of the block electrode 122 by a distance of 0.1 to 15 micrometers. Preferably, in some embodiments, this distance extending towards the center of the block electrode 122 can be 1 to 6 micrometers, for example, 2 micrometers, 3 micrometers, 4 micrometers, or 5 micrometers. Optionally, the ratio of the distance that the roughened structure 11 covered by the block electrode 122 extends from the outer sidewall 33 towards the center of the block electrode 122 to the size of the block electrode 122 is no greater than 1 / 3. The size of the block electrode 122 can be understood as follows: when the block electrode 122 is circular, its size is its diameter; when the block electrode 122 is square, its size is its side length.

[0060] In some embodiments, such as Figure 5As shown, the light-emitting diode is a vertically oriented light-emitting diode. The light-emitting diode also includes a second electrode 14, an insulating layer 16, a current blocking layer 18, a bonding layer 20, a substrate 22, and a back metal layer 24.

[0061] The first electrode 12 and the second electrode 14 are located on the upper and lower sides of the semiconductor stack 10, respectively. The second electrode 14 is disposed on the lower surface of the second semiconductor layer 103. The second electrode 14 can be made of a transparent conductive material or a metallic material, and its suitability can be selected according to the doping of the surface layer (such as a p-type GaN surface layer) of the second semiconductor layer 103. In some embodiments, the second electrode 14 is made of a transparent conductive material, which may include indium tin oxide (ITO), indium zinc oxide (IZO), indium oxide (InO), tin oxide (SnO), cadmium tin oxide (CTO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), zinc tin oxide (ZTO), gallium-doped zinc oxide (GZO), tungsten-doped indium oxide (IWO), or zinc oxide (ZnO), but the embodiments disclosed herein are not limited thereto.

[0062] An insulating layer 16 covers the semiconductor stack 10. The insulating layer 16 is used to prevent electrical connection between the first semiconductor layer 101 and the second semiconductor layer 103 due to leakage of conductive material, reducing short-circuit abnormalities in the light-emitting diode, but this disclosure is not limited to this. The material of the insulating layer 16 includes a non-conductive material. The non-conductive material is preferably an inorganic material or a dielectric material. The inorganic material may include silicone. The dielectric material includes electrically insulating materials such as aluminum oxide, silicon nitride, silicon oxide, titanium oxide, or magnesium fluoride. For example, the insulating layer 16 may be silicon dioxide, silicon nitride, titanium oxide, tantalum oxide, niobium oxide, barium titanate, or a combination thereof, such as a Bragg mirror (DBR) formed by repeatedly stacking two materials with different refractive indices.

[0063] A current blocking layer 18 is disposed on the lower surface of the first semiconductor and connected to the second electrode 14. The current blocking layer 18 is used to block the vertical flow of current to further improve the current spreading performance of the light-emitting diode. The current blocking layer 18 may contain a non-conductive material.

[0064] A bonding layer 20 is disposed on the lower surface of the second electrode 14. The bonding layer 20 is a bonding metal material used to adhere one side of the second electrode 14 to the substrate 22, such as gold, tin, titanium, nickel, platinum, etc. The bonding layer 20 can be a single-layer structure or a multi-layer structure, and can be a combination of various materials.

[0065] Substrate 22 is disposed on the lower surface of bonding layer 20. Substrate 22 is a conductive substrate, which can be silicon, silicon carbide, or a metal substrate, wherein the metal substrate can be copper, tungsten, or molybdenum. In order to support the semiconductor stack 10 with sufficient mechanical strength, the thickness of substrate 22 can be 50 μm or more. In addition, in order to facilitate the machining of substrate 22 after bonding to semiconductor stack 10, the thickness of substrate 22 can be made not to exceed 300 μm.

[0066] A back metal layer 24 is disposed on the lower surface of the substrate 22. The back metal layer 24 is formed on the back side of the substrate 22 in a full-surface manner. In this embodiment, the substrate 22 is a conductive support substrate, and the first electrode 12 and the back metal layer 24 are formed on both sides of the substrate 22 to enable current to flow vertically through the semiconductor stack 10 and provide a uniform current density.

[0067] In some embodiments, such as Figure 6 As shown, the light-emitting diode (LED) is a horizontally structured LED. The LED also includes a second electrode 14. The first electrode 12 and the second electrode 14 are disposed on the same side of the first semiconductor layer 101. Furthermore, in some embodiments, when the surface of the second semiconductor layer 103 is also roughened, the sidewalls of the second electrode 14 can also cover the roughened surface of the second semiconductor layer 103 to form a low contact barrier region, thereby improving the current spreading performance of the LED.

[0068] In some embodiments, such as Figure 7 and Figure 8 As shown, Figure 7 This is a top view schematic diagram of a light-emitting diode provided in another embodiment of the present invention. Figure 8 yes Figure 7 A schematic diagram of the cross-sectional structure taken from the middle. Compared to Figure 5The main difference between this embodiment and the vertically structured light-emitting diode is that the light-emitting diode further includes a transparent conductive layer 52 and a metal reflective layer 54. The transparent conductive layer 52 is disposed on the lower surface of the second semiconductor layer 103 and covers the current blocking layer 18. The transparent conductive layer 52 can be made of a transparent conductive material, which may include indium tin oxide (ITO), indium zinc oxide (IZO), indium oxide (InO), tin oxide (SnO), etc., but this embodiment is not limited thereto. The metal reflective layer 54 covers the transparent conductive layer 52. The metal reflective layer 54 mainly serves to reflect light, and the material of the metal reflective layer 54 may include Ag metal. In some embodiments, Figure 7 The pad electrodes located at the lower left and lower right can also be adjusted to a similar position. Figure 9 It is located in the middle.

[0069] In some embodiments, such as Figure 9 and Figure 10 As shown, Figure 9 This is a top view schematic diagram of a light-emitting diode provided in another embodiment of the present invention. Figure 10 yes Figure 9 A schematic diagram of the cross-sectional structure taken from the middle. Compared to Figure 7 Regarding the vertical structure of the light-emitting diode shown, the main difference in this embodiment is that the transparent conductive layer 52 is disposed on the lower surface of the second semiconductor layer 103, but does not cover the current blocking layer 18. The metal reflective layer 54 still covers the transparent conductive layer 52, but does not completely cover the current blocking layer 18. In some embodiments, Figure 9 The pad electrode located in the middle can also be adjusted to a similar position. Figure 7 The center is located near the lower left and lower right.

[0070] The present invention also provides a light-emitting device, which includes a circuit board and a light-emitting diode, wherein the light-emitting diode is disposed on the circuit board, and the light-emitting diode is the light-emitting diode provided in any of the above embodiments.

[0071] In summary, the light-emitting diode and light-emitting device provided in one embodiment of the present invention, by covering the roughened structure 11 with the first electrode 12, allows a portion of the first electrode 12 to be directly deposited onto the roughened structure 11 during the evaporation process. Since the roughened structure 11 undergoes etching, free atoms or dielectric oxides on the surface of the first semiconductor in this region are effectively removed. Furthermore, the plasma treatment before the first electrode 12 is deposited simultaneously increases the nitrogen vacancies on the surface of the first semiconductor in this region, thereby lowering the contact barrier at the contact between the first electrode 12 and the roughened structure 11. In other words, the contact area between the first electrode 12 and the first semiconductor layer 101 forms a high contact barrier region and a low contact barrier region. Current tends to diffuse through the low contact barrier region to the light-emitting region, thus effectively improving the current diffusion performance of the light-emitting diode and enhancing its quality.

[0072] Furthermore, those skilled in the art should understand that although many problems exist in the prior art, each embodiment or technical solution of the present invention can be improved in only one or a few aspects, without necessarily solving all the technical problems listed in the prior art or the background art simultaneously. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as a limitation on that claim.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A light-emitting diode, characterized in that: The light-emitting diode includes: A semiconductor stack, comprising a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked sequentially, wherein the surface of the first semiconductor layer has a roughened structure; The first electrode is disposed on the surface of the first semiconductor layer; Wherein, the first electrode at least covers a portion of the roughened structure; and a portion of the first electrode does not cover the roughened structure; the first electrode includes a side region and a central region, the side region being connected to the central region, the side region covering the roughened structure, and the central region not covering the roughened structure.

2. The light-emitting diode according to claim 1, characterized in that: The vertical projection points of at least one lower edge of the first electrode in the horizontal plane are distributed within the vertical projection line segment of the roughened structure in the horizontal plane.

3. The light-emitting diode according to claim 1, characterized in that: The first electrode includes at least one electrode extension having opposing first and second sidewalls. The roughened structure covered by the electrode extension extends from the first sidewall toward the second sidewall for a distance of 0.1 to 10 micrometers.

4. The light-emitting diode according to claim 1, characterized in that: The first electrode includes at least one electrode extension having opposing first and second sidewalls. The ratio of the distance the roughened structure covered by the electrode extension extends from the first sidewall to the second sidewall to the distance between the first and second sidewalls is no greater than 1 / 3.

5. The light-emitting diode according to claim 3 or 4, characterized in that: The distance by which the roughened structure covered by the electrode extension extends from the first sidewall to the second sidewall is greater than or equal to the distance by which the roughened structure covered by the electrode extension extends from the second sidewall to the first sidewall.

6. The light-emitting diode according to claim 3 or 4, characterized in that: The roughened structure covered by the electrode extension extends from the second sidewall to the first sidewall by a distance of 0 to 10 micrometers.

7. The light-emitting diode according to claim 3 or 4, characterized in that: The second sidewall is closer to the edge of the light-emitting diode than the first sidewall.

8. The light-emitting diode according to claim 1, characterized in that: The first electrode includes a block electrode having a peripheral sidewall, and the roughened structure covered by the block electrode extends from the peripheral sidewall toward the center of the block electrode by a distance of 0.1 to 15 micrometers.

9. The light-emitting diode according to claim 1, characterized in that: The first electrode includes a block electrode with a peripheral sidewall. The ratio of the distance that the roughened structure covered by the block electrode extends from the peripheral sidewall toward the center of the block electrode to the size of the block electrode is no greater than 1 / 3.

10. The light-emitting diode according to claim 1, characterized in that: The first electrode has opposing inner and outer sidewalls, and the distance by which the roughened structure covered by the first electrode extends from the inner sidewall to the outer sidewall is greater than or equal to the distance by which the roughened structure covered by the first electrode extends from the outer sidewall to the inner sidewall.

11. The light-emitting diode according to claim 10, characterized in that: The outer sidewall is closer to the edge of the light-emitting diode than the inner sidewall.

12. The light-emitting diode according to claim 1, characterized in that: From the perspective of the longitudinal cross-section of the light-emitting diode, the side region refers to the region formed by extending from the sidewall of the first electrode toward the center of the first electrode. The sum of the lengths of the vertical projection line segments of the side region on the horizontal plane is defined as the first length, and the sum of the lengths of the vertical projection line segments of the center region on the horizontal plane is defined as the second length. The ratio of the first length to the second length is not greater than 2.

13. The light-emitting diode according to claim 1, characterized in that: The area ratio of the side region to the central region is no greater than 2.

14. The light-emitting diode according to claim 1, characterized in that: The area ratio of the side region to the area of ​​the first electrode is no greater than 2 / 3.

15. The light-emitting diode according to claim 1, characterized in that: The light-emitting diode also includes a second electrode, which is disposed on the lower surface of the second semiconductor layer.

16. The light-emitting diode according to claim 15, characterized in that: The light-emitting diode further includes an insulating layer, a current blocking layer, a bonding layer, a substrate, and a back metal layer. The insulating layer covers the semiconductor stack. The current blocking layer is disposed on the lower surface of the second semiconductor layer and connected to the second electrode. The bonding layer is disposed on the lower surface of the second electrode. The substrate is disposed on the lower surface of the bonding layer. The back metal layer is disposed on the lower surface of the substrate.

17. The light-emitting diode according to claim 1, characterized in that: The roughness of the roughened structure is 0.2 ~ 1 μm.

18. The light-emitting diode according to claim 1, characterized in that: The light-emitting diode is a vertically oriented light-emitting diode.

19. The light-emitting diode according to claim 1, characterized in that: The current density of the light-emitting diode is ≥1A / mm². 2 .

20. A light-emitting device, characterized in that: The light-emitting device includes a circuit board and a light-emitting diode, wherein the light-emitting diode is disposed on the circuit board, and the light-emitting diode is the light-emitting diode as described in any one of claims 1 to 19.

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