Light emitting diode and light emitting device

Abstract

The invention provides a light-emitting diode and a light-emitting device, the upper surface of an electrode structure in the light-emitting diode is provided with an opening part, the electrode structure is provided with a first part and a second part, the boundary line of the first part and the second part is located in the bottom area of the opening part, and the metal continuity of the first part is better than that of the second part. In other words, the integrity of the metal film layer of the first part is better than that of the metal film layer of the second part, and preferably, the first part does not have defects such as cracks and holes which damage the continuity or integrity of the first part; or the crack degree (crack gap) or the void ratio (porosity) of the second part is far smaller than the crack degree or the void ratio of the second part. Therefore, at least the first part in the electrode structure continuously and uniformly covers the side wall of the electrode through hole, the first part is enough to ensure good conductivity of the light-emitting diode, and meanwhile, due to the fact that the electrode structure has good coverage and uniformity, the reliability of the light-emitting diode can also be improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor devices and apparatus, and particularly to a light-emitting diode and a light-emitting device. Background Technology

[0002] Light-emitting diodes (LEDs) have advantages such as high luminous intensity, high efficiency, small size, and long lifespan, and are considered one of the most promising light sources today. In recent years, LEDs have been widely used in daily life, such as lighting, signal display, backlighting, automotive lights, and large-screen displays. At the same time, these applications have also placed higher demands on the brightness and chip size of LEDs.

[0003] With the rapid adoption of Micro LED technology and high-resolution displays, chip sizes are shrinking. This leads to increased localized stress in the electrode areas during fabrication, and electrode problems can arise due to poor step coverage. Current Micro LED chip manufacturing processes typically employ electron beam evaporation (EBD) to form metal electrodes. However, due to the highly directional nature of EBD, complex structures such as sidewall steps, micropores, and microtrenches often exist on the chip surface, especially near electrode holes. These complex surfaces often exhibit poor metal coverage, making it difficult to obtain a uniform and continuous metal coating. This is particularly pronounced with complex through-hole structures on the sidewalls, which easily create deposition dead zones. These discontinuities lead to a series of problems, affecting the chip's conductivity and reliability. Summary of the Invention

[0004] In view of the deficiencies and defects in the conductivity and reliability of light-emitting diodes caused by the defects in electrode coverage and continuity in the prior art, the present invention provides a light-emitting diode and a light-emitting device to solve one or more of the above-mentioned problems.

[0005] One embodiment of this application provides a light-emitting diode, which includes at least:

[0006] A semiconductor epitaxial stack includes a first semiconductor layer, an active layer, and a second semiconductor layer stacked sequentially; the semiconductor epitaxial stack has a first mesa and a second mesa, the surface of the first mesa is the exposed first semiconductor layer, the surface of the second mesa is the second semiconductor layer, and the first mesa is lower than the second mesa;

[0007] Electrode through-holes are located above the first and second mezzanine surfaces;

[0008] An electrode structure covers the sidewalls and bottom of the electrode through-hole, and the upper surface of the electrode structure has an opening; the electrode structure has a first part and a second part, and the boundary line between the first part and the second part is located in the bottom region of the opening;

[0009] The metal continuity of the first part is superior to that of the second part.

[0010] Another embodiment of this application provides a light-emitting device, which includes a circuit board and a light-emitting element disposed on the circuit board, wherein the light-emitting element includes the light-emitting diode provided in this application.

[0011] As described above, the light-emitting diode and light-emitting device of this application have the following beneficial effects:

[0012] The light-emitting diode (LED) of this application has an opening on the upper surface of its electrode structure. The electrode structure has a first portion and a second portion, with the boundary line located in the bottom region of the opening. The metal continuity of the first portion is superior to that of the second portion; that is, the integrity of the metal film layer in the first portion is superior to that in the second portion. Preferably, the first portion is free from defects such as cracks or holes that could disrupt its continuity or integrity. Even if cracks or holes exist in the first portion, the degree of cracking (crack gap) or porosity (porosity) is much smaller than that in the second portion. This ensures that at least the first portion of the electrode structure continuously and uniformly covers the sidewall of the electrode via. This first portion is sufficient to guarantee the good conductivity of the LED. Even if cracks or holes appear in the second portion of the electrode structure, it will not affect the conductivity of the LED. Furthermore, due to the good coverage and uniformity of the electrode structure, the reliability of the LED is also improved. Attached Figure Description

[0013] Figure 1 The diagram shown is a schematic diagram of the structure of a light-emitting diode provided in Embodiment 1 of the present invention.

[0014] Figure 2 Displayed as Figure 1 A partially enlarged structural diagram of the first electrode section.

[0015] Figure 3 Displayed as Figure 1 A partially enlarged schematic diagram of the second electrode section.

[0016] Figure 4 Shown as an optional example, Figure 1 The diagram shows a top view of the light-emitting diode, with only a portion of the structure's projected outline shown.

[0017] Figure 5Shown as an optional example, Figure 1 The diagram shows a top view of the light-emitting diode, with only a portion of the structure's projected outline shown.

[0018] Figure 6 Shown as an optional example of vapor-deposited metal material formation Figure 1 A schematic diagram of the electrode structure shown.

[0019] Figure 7 Shown as another optional example, the formation of vapor-deposited metallic materials Figure 1 A schematic diagram of the electrode structure shown.

[0020] Figure 8 The diagram shown is a schematic diagram of the light-emitting device provided in Embodiment 2 of the present invention.

[0021] Component designation explanation

[0022] 100, Light Emitting Diode; 101, Front Plated Surface; 102, Back Plated Surface; 110, Substrate; 111, Front Side; 112, Back Side; 120, Semiconductor Epitaxial Stack; 1201, First Mesa; 1202, Second Mesa; 121, First Semiconductor Layer; 122, Active Layer; 123, Second Semiconductor Layer; 130, Transparent Conductive Layer; 140, Insulating Protective Layer; 150, Reflective Layer; 161, First Electrode; 1610, First electrode through hole; 1611, First part; 1612, Second part; 1600, Opening; 160-1, First sidewall; 160-11, First section; 160-12, Second section; 160-2, Second sidewall; 162, Second electrode; 1620, Second electrode through hole; 1621, First part; 1622, Second part; 171, First platform area; 172, Second platform area.

[0023] 200. Target material; 201. Electron beam.

[0024] 300, Light-emitting device; 301, Circuit board; 302, Light-emitting unit. Detailed Implementation

[0025] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0026] In existing technologies, as the size of light-emitting diodes (LEDs) gradually shrinks, for example to the 10 μm to 50 μm level, localized stress easily forms in the electrode area during the LED manufacturing process. This localized stress concentration makes the electrode structure highly susceptible to defects such as cracks or holes forming on the sidewalls or corners of the electrode vias. These cracks or holes cause current congestion or uneven current distribution, leading to deterioration of electrode conductivity. The cracks or holes also become channels for the intrusion of moisture, oxygen, fluorine, etc., causing oxidation or corrosion of the internal chip structure, increasing the chip's environmental sensitivity. Under high temperature and humidity environments, or during long-term aging tests with continuous current injection, the cracks or holes can further expand, damaging the internal film layers of the chip, causing component failure, and reducing chip reliability.

[0027] To address the aforementioned deficiencies of existing light-emitting diodes (LEDs), one embodiment of this application provides an LED comprising at least:

[0028] A semiconductor epitaxial stack includes a first semiconductor layer, an active layer, and a second semiconductor layer stacked sequentially; the semiconductor epitaxial stack has a first mesa and a second mesa, the surface of the first mesa is the exposed first semiconductor layer, the surface of the second mesa is the second semiconductor layer, and the first mesa is lower than the second mesa;

[0029] Electrode through-holes are located above the first and second mezzanine surfaces;

[0030] An electrode structure covers the sidewalls and bottom of the electrode through-hole, and the upper surface of the electrode structure has an opening; the electrode structure has a first part and a second part, and the boundary line between the first part and the second part is located in the bottom region of the opening;

[0031] The metal continuity of the first part is superior to that of the second part.

[0032] As described above, the metal continuity of the first part of the electrode structure is superior to that of the second part; that is, the integrity of the metal film layer in the first part is superior to that in the second part. Preferably, the first part is free from defects such as cracks or holes that could disrupt its continuity or integrity. Even if cracks or holes exist in the first part, the degree of cracking (crack gap) or porosity (porosity) is much smaller than that in the second part. This ensures that at least the aforementioned first part of the electrode structure continuously and uniformly covers the sidewalls of the electrode via, which is sufficient to guarantee the good conductivity of the LED. Even if cracks or holes appear in the second part of the electrode structure, it will not affect the conductivity of the LED. Furthermore, due to the good coverage and uniformity of the electrode structure, the reliability of the LED can also be improved.

[0033] Optionally, the dividing line between the first part and the second part is the bisector of the bottom region of the opening.

[0034] The dividing line between the first part and the second part is the bisector of the bottom area of ​​the opening. This ensures that the first part is at least half of the electrode structure, thus guaranteeing sufficient coverage area and ensuring the conductivity reliability of the entire electrode structure.

[0035] Optionally, the first portion is located on the facing surface of the electrode through hole when the electrode structure is formed by vapor deposition of the metal material; the second portion is located on the back surface of the electrode through hole when the electrode structure is formed by vapor deposition of the metal material.

[0036] The first part being located on the vapor deposition surface is conducive to forming a dense and continuous structure, ensuring that the metal continuity of the first part is better than that of the second part.

[0037] Optionally, the metal material of the electrode structure extends from the sidewall of the electrode via to above the semiconductor epitaxial stack. The first portion has a first sidewall above the semiconductor epitaxial stack, and the second portion has a second sidewall above the semiconductor epitaxial stack. The angle between the first sidewall and the plane containing the surface of the semiconductor epitaxial stack is smaller than the angle between the second sidewall and the plane containing the surface of the semiconductor epitaxial stack.

[0038] The difference in the sidewall angles between the first and second parts above the semiconductor epitaxial stack results in a larger coverage area for the first part on the semiconductor epitaxial stack, which correspondingly increases the electrode area and improves the conductivity of the electrode.

[0039] Optionally, the first sidewall has a first segment connected to the semiconductor epitaxial stack and a second segment connected to the first segment, wherein the angle between the first segment and the plane containing the surface of the semiconductor epitaxial stack is smaller than the angle between the second segment and the plane containing the surface of the semiconductor epitaxial stack.

[0040] The aforementioned configuration of the sidewalls of the first part enables the first part to form a trailing portion on the semiconductor epitaxial stack. This trailing portion reduces the inclination of the sidewalls of the first part, which is beneficial for improving the coverage and adhesion of the metal material and enhancing the reliability of the electrode structure.

[0041] Optionally, the metal material of the electrode structure extends from the sidewall of the electrode via to the surface of the semiconductor epitaxial stack. The first portion forms a first platform region above the semiconductor epitaxial stack, and the second portion forms a second platform region above the semiconductor epitaxial stack. The width L1 of the first platform region is greater than the width L2 of the second platform region.

[0042] Optionally, the width L2 of the second platform region satisfies: 0≤L2≤0.5 μm.

[0043] Optionally, the width L1 of the first platform region satisfies: 0.5 μm ≤ L1 ≤ 2 μm.

[0044] The formation of the aforementioned first platform region can also increase the coverage area of ​​the first part of the electrode structure, and also allow the first part to transition to the first sidewall more smoothly, which is beneficial to improving the coverage uniformity of the electrode structure and improving the reliability of the electrode structure.

[0045] Optionally, the projection is made on the plane containing the surface of the semiconductor epitaxial stack, and within the bottom range of the electrode via, the projection profile of the opening in the first part and the bottom projection profile of the electrode via have a first minimum distance L3, and the projection profile of the opening in the second part and the bottom projection profile of the electrode via have a second minimum distance L4, where L3 > L4.

[0046] Optionally, the first minimum distance L3 satisfies: 0 < L3 ≤ 0.1 μm.

[0047] Optionally, the second minimum distance L4 satisfies: 0 ≤ L4 ≤ 0.05 μm.

[0048] Optionally, the coverage area S1 of the first part at the bottom of the electrode through hole is greater than the coverage area S2 of the second part at the bottom of the electrode through hole.

[0049] Optionally, the ratio of S1 to S2 is between 3:1 and 10:1.

[0050] The minimum distance and coverage area settings of the first and second parts increase the coverage of the first part at the bottom of the electrode via, ensuring that the electrode structure and the semiconductor epitaxial stack have sufficient contact area, thereby ensuring the conductivity of the light-emitting diode.

[0051] Optionally, the first part and the second part are formed as a continuous structure.

[0052] Since the first and second parts of the electrode structure form a continuous structure, the structural integrity of the electrode structure is guaranteed, which helps to improve its conductivity reliability.

[0053] Optionally, the light-emitting diode further includes:

[0054] An insulating protective layer covers the surfaces and sidewalls of the first mesa and the second mesa, as well as the sidewalls of the semiconductor epitaxial stack.

[0055] A reflective layer is located above the insulating protective layer, and the electrode via penetrates both the reflective layer and the insulating protective layer.

[0056] The aforementioned reflective layer can also be a stack of insulating materials. While increasing the reflection of light, it can work together with the insulating protective layer to provide insulation protection, further improving the reliability of the light-emitting diode.

[0057] Optionally, the side adjacent to the first and second platform is defined as the inner side of the light-emitting diode, and the side opposite to the first and second platform is defined as the outer side of the light-emitting diode. The facing side is the side closer to the outer side, and the back plating side is the side closer to the inner side.

[0058] By using the outer side of the LED as the plating surface, the coverage area of ​​the first part is increased without short circuits or other issues, thus ensuring the reliability of the LED.

[0059] Another embodiment of the present invention provides a light-emitting device, which includes a circuit board and a light-emitting element disposed on the circuit board, the light-emitting element including the light-emitting diode provided in this application. This light-emitting device includes the light-emitting diode of this application, and therefore can achieve good light extraction efficiency and brightness.

[0060] Example 1

[0061] This embodiment provides a light-emitting diode, such as Figure 1 As shown, the light-emitting diode 100 includes at least a semiconductor epitaxial stack 120, electrode vias, and electrode structures. The aforementioned semiconductor epitaxial stack 120 comprises a first semiconductor layer 121, an active layer 122, and a second semiconductor layer 123 stacked sequentially. Referring also to… Figure 1 The light-emitting diode 100 may also include a substrate 110 having a front side 111 and a back side 112, and a semiconductor epitaxial stack 120 located on the front side 111 of the substrate 110.

[0062] The material of the substrate 110 can be selected from substances such as sapphire (Al2O3), SiC, GaAs, GaN, ZnO, Si, GaP, InP, and Ge, but is not limited thereto. The substrate 110 can be a light-transmitting substrate capable of transmitting light in the ultraviolet wavelength band, such as a sapphire substrate. In this embodiment, the side of the semiconductor epitaxial stack 120 adjacent to the front surface 111 of the substrate 110 is the light-emitting surface side. In order to increase the light extraction rate, the light-emitting surface side is usually formed into a roughened surface.

[0063] The semiconductor epitaxial stack 120 of this embodiment can be any semiconductor epitaxial stack 120 capable of emitting light under the action of voltage. In this embodiment, each material layer in the semiconductor epitaxial stack 120 can be formed by means such as Physical Vapor Deposition (PVD), Chemical Vapor Deposition (CVD), Epitaxy Growth Technology, and Atomic Layer Deposition (ALD). The semiconductor epitaxial stack 120 is a semiconductor material capable of providing conventional radiation such as ultraviolet, blue, green, yellow, red, infrared light, etc. By adjusting the composition ratio of the semiconductor material in the active layer 122, light of a target wavelength is radiated. For example, a gallium nitride-based semiconductor stack doped with elements such as aluminum and indium mainly provides radiation in the 200nm - 570nm band; or an aluminum gallium indium phosphide-based or aluminum gallium arsenide-based semiconductor stack mainly provides radiation in the 550nm - 950nm band.

[0064] When the semiconductor epitaxial stack 120 emits light in the ultraviolet wavelength band, each semiconductor layer of the light-emitting structure can include In containing aluminum (Al) x1 Al y1 Ga 1-x1-y1 N (0 ≤ x1 ≤ 1, 0 < y1 ≤ 1, 0 ≤ x1 + y1 ≤ 1) material. Among them, the Al component can be represented by the ratio of the total atomic weight including the atomic weights of In, Ga, and Al to the atomic weight of Al. For example, when the Al component accounts for 40%, the Ga component in Al 0.4 Ga 0.6 N can account for 60%.

[0065] The first semiconductor layer 121 in the above semiconductor epitaxial stack 120 can be realized by a compound semiconductor such as a III-V group or a II-VI group, and can be doped with a first dopant. The first semiconductor layer 121 can be In x1 Al y1 Ga 1-x1-y1The empirical formula of the semiconductor material of N (0≤x1≤1, <y1≤1, 0≤x1 + y1≤1) can be, for example, a material selected from AlGaN, AlN, InAlGaN, etc. The first dopant can be an N-type dopant such as Si, Ge, Sn, Se, Te. When the first dopant is an N-type dopant, the first semiconductor layer 121 doped with the first dopant is an N-type semiconductor layer.

[0066] The active layer 122 is disposed between the first semiconductor layer 121 and the second semiconductor layer 123. The active layer 122 is a layer where electrons (or holes) injected through the first semiconductor layer 121 meet holes (or electrons) injected through the second semiconductor layer 123. As electrons and holes recombine and jump to a lower energy level, light with an ultraviolet wavelength can be generated in the active layer 122. The active layer 122 can have a structure selected from a single well structure, a multi-well structure, a single quantum well structure, a multi quantum well (MQW) structure, a quantum dot structure, or a quantum wire structure, but is not limited thereto.

[0067] The active layer 122 can include a plurality of well layers and barrier layers. The well layers and barrier layers can have an empirical formula of In x2 Al y2 Ga 1-x2-y2 N (0≤x2≤1, 0<y2≤1, 0≤x2 + y2≤1). The aluminum component of the well layer can vary according to the emission light wavelength. As the aluminum component increases, the wavelength of the light emitted from the well layer can become smaller.

[0068] The second semiconductor layer 123 is formed on the active layer 122 and can be a compound semiconductor such as a III-V group or a II-VI group, and the second semiconductor layer 123 can be doped with a second dopant. The second semiconductor layer 123 can be a semiconductor material with an empirical formula of In x5 Al y2 Ga 1-x5-y2 N (0≤x5≤1, 0<y2≤1, 0≤x5 + y2≤1), or can be a material selected from AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, Ba, etc., the second semiconductor layer 123 doped with the second dopant is a p-type semiconductor layer.

[0069] Although not shown, it can be understood that an electron blocking layer (EBL) etc. can be provided between the active layer 122 and the second semiconductor layer 123. As a confinement layer of the active layer 122, the electron blocking layer can reduce the leakage of electrons.

[0070] Refer to Figure 1The semiconductor epitaxial stack 120 has a first mesa 1201 and a second mesa 1202. For example, the first mesa 1201 can be formed by etching away part of the active layer 122 and the second semiconductor layer 123 to expose the first semiconductor layer 121. The unetched portion of the semiconductor epitaxial stack 120 forms the second mesa 1202, which is the light-emitting region of the light-emitting diode 100. (See also...) Figure 1 The first mesa 1201 and the second mesa 1202 are arranged side by side. In an optional example, the first mesa 1201 can be an open mesa formed on one side or a corner of the light-emitting diode 100. In another optional example, it can be as follows... Figure 1 The diagram shows a mesa structure formed in a semiconductor epitaxial stack 120, where the first mesa 1201 is surrounded by the second mesa 1202.

[0071] Refer again Figure 1 The light-emitting diode 100 in this embodiment also includes electrode vias and electrode structures formed in the electrode vias. Specifically, the electrode vias include a first electrode via 1610 located above the first mesa 1201 and a second electrode via 1620 formed above the second mesa 1202. Referring also to... Figure 1 The light-emitting diode 100 also includes an insulating protective layer 140 and a reflective layer 150. The insulating protective layer 140 covers the surface and sidewalls of the light-emitting diode 100, and the reflective layer 150 is formed above the insulating protective layer 140, specifically above the insulating protective layer 140 on the surface and sidewalls of the first mesa 1201 and the second mesa 1202. The insulating protective layer 140 can be an insulating oxide, insulating nitride, etc. For example, it can be one or more of SiO2, Si3N4, Al2O3, TiO2, ZnO, HfO2, etc. The insulating protective layer 140 can be a single structure or a multilayer structure. Its thickness is between 100 Å and 3000 Å, and further, between 500 Å and 2000 Å. The aforementioned insulating protective layer 140 can block impurities such as water vapor and electrolyte ions, which helps to improve the brightness of the light-emitting diode and reduce the light decay of the device.

[0072] In an optional example, the aforementioned reflective layer 150 may be a Bragg reflective layer comprising a high-refractive-index material layer and a low-refractive-index material layer stacked on top of each other. Here, "high-refractive-index" and "low-refractive-index" refer to the relative refractive indices of the stacked material layers, and do not represent specific refractive index values. The aforementioned high-refractive-index material layer and low-refractive-index material layer may be SiO2, SiN, or SiO2. x N y TiO xA dash breech-guided mirror (DBR) formed by repeatedly stacking two or more of the following materials: Si3N4, Al2O3, TiN, AlN, ZrO2, TiAlN, TiSiN, HfO2, TaO2, NbO2, or MgF2. For example, in this embodiment, the high refractive index material layer is TiO2. x Layers (e.g., TiO2, Ti2O3, or Ti3O5) or NbO y The high-refractive-index material layer (e.g., NbO2 or Nb3O5) and the low-refractive-index material layer are SiO2 layers. The total number of stacked layers of the high-refractive-index and low-refractive-index material layers is between 2 and 100 layers, further between 2 and 10 layers, and even further between 2 and 5 layers. The thickness of the high-refractive-index and low-refractive-index material layers is between 100 Å and 1000 Å, further between 200 Å and 800 Å, 500 Å and 1000 Å, and 500 Å and 800 Å. The thicknesses of the high-refractive-index and low-refractive-index material layers are usually different. As described above, the reflective layer 150 is a stack of insulating materials, which, while increasing light reflection, can work together with the insulating protective layer 140 to provide insulation protection, further improving the reliability of the light-emitting diode 100.

[0073] In the optional examples, refer to Figure 1 The light-emitting diode 100 also includes a transparent conductive layer 130, which is formed above the second mesa 1202. Specifically, the transparent conductive layer 130 can completely cover the second semiconductor layer 123 exposed on the second mesa 1202, or it can partially cover the second semiconductor layer 123. Figure 1 As shown, in this embodiment, the transparent conductive layer 130 covers a portion of the second semiconductor layer 123. There is a certain distance between the edge of the transparent conductive layer 130 and the edge of the second semiconductor layer 123; that is, the transparent conductive layer 130 is not covered above the second semiconductor layer 123 at the edge of the second mesa 1202. The transparent conductive layer 130 is formed of a transparent conductive material, including but not limited to indium tin oxide (ITO), indium oxide (InO), tin oxide (SnO), cadmium tin oxide (CTO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), zinc tin oxide (ZTO), gallium zinc oxide (GZO), indium tungsten oxide (IWO), zinc oxide (ZnO), gallium phosphide (GaP), indium cerium oxide (ICO), indium tungsten oxide (IWO), indium titanium oxide (ITiO), indium zinc oxide (IZO), indium gallium oxide (IGO), gallium aluminum zinc oxide (GAZO), or combinations of the above materials.

[0074] Refer again Figure 1A first electrode via 1610 penetrates the reflective layer 150 and the insulating protective layer 140 above the first mesa 1201, exposing the first semiconductor layer 121 of the first mesa 1201. A second electrode via 1620 penetrates the reflective layer 150 and the insulating protective layer 140 above the second mesa 1202, exposing the aforementioned transparent conductive layer 130. The electrode structure includes a first electrode 161 and a second electrode 162. The first electrode 161 is formed above the first mesa 1201 and fills the bottom and sidewalls of the first electrode via 1610 to be electrically connected to the first semiconductor layer 121. The second electrode 162 is formed above the second mesa 1202 and fills the sidewalls and bottom of the second electrode via 1620 to be electrically connected to the second semiconductor layer 123 via the transparent conductive layer 130.

[0075] In this embodiment, the upper surface of the electrode structure has an opening, and the electrode structure has a first part and a second part. The metal continuity of the first part is better than that of the second part, that is, the integrity of the metal film layer in the first part is better than that in the second part. Preferably, the first part is free from defects such as cracks or holes that would disrupt its continuity or integrity; even if cracks or holes exist in the first part, the degree of cracking (crack gap) or porosity (porosity) is much smaller than that in the second part. As is generally understood, the aforementioned facing surface and back surface are the opposite sides of the electrode through-hole. As described above, the first part can ensure good conductivity of the entire electrode structure, and regardless of whether cracks or holes exist in the second part, the conductivity of the electrode structure can be achieved by the first part, ensuring its reliability.

[0076] Specifically, refer to Figure 1 and Figure 2 The first electrode 161 mentioned above includes a first portion 1611 and a second portion 1612. For example... Figure 2 As shown, the surface of the first electrode 161 has an opening 1600, and the boundary line between the first portion 1611 and the second portion 1612 is located in the bottom region of the opening 1600. Further, the boundary line is the bisector of the bottom region of the opening 1600, meaning that in the bottom region, the area ratio of the first portion 1611 and the second portion 1612 is 1:1. This ensures that the first portion 1611 is at least half of the first electrode 161, guaranteeing sufficient coverage area and thus ensuring the conductivity reliability of the entire electrode structure.

[0077] like Figure 1 and Figure 2As shown, the metal material forming the electrode structure extends from the sidewall of the first electrode via 1610 to above the semiconductor epitaxial stack 120. The first portion 1611 forms a first sidewall 160-1 above the semiconductor epitaxial stack 120, and the second portion 1612 forms a second sidewall 160-2 above the semiconductor epitaxial stack 120. (Refer to...) Figure 1 The first sidewall 160-1 and the plane containing the surface of the semiconductor epitaxial stack 120 have an included angle α1, and the second sidewall 160-2 and the plane containing the surface of the semiconductor epitaxial stack 120 have an included angle α2. Both angles α1 and α2 refer to acute angles between the corresponding sidewalls and the plane, and angle α1 is smaller than angle α2, meaning the first sidewall 160-1 is more gently sloping than the second sidewall 160-2. The difference in the included angles of the sidewalls of the first portion 1611 and the second portion 1612 above the semiconductor epitaxial stack 120 results in a larger coverage area of ​​the first portion 1611 on the semiconductor epitaxial stack 120, correspondingly increasing the electrode area and improving the electrode's conductivity.

[0078] Refer again Figure 2 The first sidewall 160-1 of the first portion 1611 of the first electrode 161 includes two portions with different inclinations. Specifically, it has a first segment 160-11 connected to the semiconductor epitaxial stack 120 and a second segment 160-12 connected to the first segment 160-11. The first segment 160-11 has an included angle α11 with the plane containing the surface of the semiconductor epitaxial stack 120, and the second segment 160-12 has an included angle α12 with the plane containing the surface of the semiconductor epitaxial stack 120. Similarly, the included angles α11 and α12 refer to the acute angles between the corresponding sidewalls and the planes, where α11 is less than α12. The aforementioned included angle feature of the first segment 160-11 and the second segment 160-12 of the first sidewall 160-1 causes the first sidewall 160-1 to exhibit a tailing phenomenon above the semiconductor epitaxial stack 120, forming a tailing portion. This tailing portion reduces the inclination of the sidewall of the first portion 1611, which is beneficial to improving the coverage and adhesion of the metal material, and increasing the reliability of the electrode structure while increasing the electrode area.

[0079] Refer again Figure 2The first portion 1611 forms a first platform region 171 above the semiconductor epitaxial stack 120, and the second portion 1612 forms a second platform region 172 above the semiconductor epitaxial stack 120. The width L1 of the first platform region 171 is greater than the width L2 of the second platform region 172. Optionally, the width L1 of the first platform region 171 satisfies: 0.5 μm ≤ L1 ≤ 2 μm. The width L2 of the second platform region 172 satisfies: 0 ≤ L2 ≤ 0.5 μm. The formation of the first platform region 171 can also increase the coverage area of ​​the first portion 1611, and also allow the first portion 1611 to transition more smoothly to the first sidewall 160-1, which is beneficial to improving the coverage uniformity of the first electrode 161 and improving the reliability of the first electrode 161.

[0080] In the optional examples, refer to Figure 4 and Figure 5 Simultaneously refer to Figure 2 Projected onto the plane containing the surface of the semiconductor epitaxial stack 120, within the bottom region of the first electrode via 1610, the projected outline of the first portion 1611 of the first electrode 161 has a first minimum distance L3 with respect to the bottom projected outline of the first electrode via 1610, and the projected outline of the second portion 1612 has a second minimum distance L4 with respect to the bottom projected outline of the first electrode via 1610, wherein L3 > L4. Optionally, the first minimum distance L3 satisfies: 0 < L3 ≤ 0.1 μm, and the second minimum distance L4 satisfies: 0 ≤ L4 ≤ 0.05 μm. The aforementioned limitation of the first minimum distance L3 and the second minimum distance L4 can increase the coverage area of ​​the first portion 1611 at the bottom of the first electrode via 1610. Specifically, as Figure 4 As shown, the first part 1611 covers an area of ​​S1 at the bottom of the first electrode through hole 1610, and the second part 1612 covers an area of ​​S2 at the bottom of the first electrode through hole 1610, where S1 is greater than S2. Furthermore, the ratio of S1 to S2 is between 3:1 and 10:1.

[0081] The increased coverage area at the bottom of the first electrode via 1610 correspondingly improves the conductivity of the first portion 1621, thereby ensuring the conductivity and reliability of the first electrode 161. The aforementioned minimum distance and coverage area settings between the first and second portions increase the coverage of the first portion at the bottom of the electrode via, ensuring sufficient contact area between the electrode structure and the semiconductor epitaxial stack, thus guaranteeing the conductivity of the light-emitting diode.

[0082] Optional examples, such as Figure 3As shown, taking the second electrode 162 as an example, the second electrode 162 also includes a first portion 1621 and a second portion 1622. The metal material forming the electrode structure extends from the sidewall of the second electrode via 1620 to above the semiconductor epitaxial stack 120. The first portion 1621 also forms a first sidewall 160-1 above the semiconductor epitaxial stack 120, and the second portion 1622 also forms a second sidewall 160-2 above the semiconductor epitaxial stack 120. (Refer to...) Figure 1 There is an angle β1 between the first sidewall 160-1 and the plane containing the surface of the semiconductor epitaxial stack 120, and an angle β2 between the second sidewall 160-2 and the plane containing the surface of the semiconductor epitaxial stack 120. Both angles β1 and β2 refer to the acute angles between the corresponding sidewalls and the plane, and angle β1 is smaller than angle β2.

[0083] Refer again Figure 3 The first sidewall 160-1 of the first portion 1621 of the second electrode 162 also includes two portions with different inclinations. That is, a first segment 160-11 connected to the semiconductor epitaxial stack 120 and a second segment 160-12 connected to the first segment 160-11, wherein the first segment 160-11 and the plane containing the surface of the semiconductor epitaxial stack 120 also have an included angle β11, and the second segment 160-12 and the plane containing the surface of the semiconductor epitaxial stack 120 have an included angle β12. Similarly, the included angles β11 and β12 refer to the acute angles between the corresponding sidewalls and the planes, wherein β11 is less than β12.

[0084] Similarly, as Figure 3 and Figure 4 As shown, a first plateau region 171 is formed on the semiconductor epitaxial stack 120 in the first portion 1611, and a second plateau region 172 is formed on the semiconductor epitaxial stack 120 in the second portion 1612. The first plateau region 171 and the second plateau region 172 have the same characteristics as the first plateau regions 171 and 172 of the first electrode 161. Similarly, projected onto the plane containing the surface of the semiconductor epitaxial stack 120, within the bottom region of the second electrode via 1620, the first portion 1621 and the second portion 1622 of the second electrode 162 have the same characteristics as the first portion 1611 and the second portion 1612 of the first electrode 161. These characteristics will not be repeated here, but can be referred to the above description of the first electrode 161. The above-described arrangement of the second electrode 162 also increases the coverage area of ​​its first portion 1621 and ensures its conductivity and reliability.

[0085] As described above, since the first electrode through hole 1610 has more complex sidewall features than the second electrode through hole 1620, the above-described configuration of the electrode structure in this embodiment is particularly suitable for the structure shown in the first electrode through hole 1610. On the one hand, it can improve the uniformity and adhesion of the metal material forming the electrode structure on the complex sidewall; on the other hand, it can increase the coverage area of ​​the metal material with a continuous structure in the electrode structure, thus ensuring the reliability of the electrode structure.

[0086] Optional examples, such as Figure 5 As shown, while keeping the direction of the vertically emitted electron beam 201 unchanged, the direction of the light-emitting diode 100 can be adjusted so that one side of the electrode through-hole faces the electron beam 210 as the plating face 101, and the opposite side is the back plating face 102. Alternatively, as... Figure 7 As shown, the light-emitting diode 100 is placed horizontally with the electrode via facing upwards. The electron beam 210 is oriented so that it faces the side of the electrode via, which is designated as the facing surface 101, and the opposite side is designated as the back surface 102. The electrode structure described above is formed by vapor deposition under the action of the electron beam 201. In an optional example, the side adjacent to the first mesa 1201 and the second mesa 1202 is defined as the inner side of the light-emitting diode 100, and the side opposite to the first mesa 1201 and the second mesa 1202 is defined as the outer side of the light-emitting diode. The facing surface 101 is preferably the side closer to the outer side, and the back surface 102 is the side closer to the inner side. Using the outer side of the light-emitting diode 100 as the facing surface 101 increases the coverage area of ​​the first part of the electrode structure while preventing short circuits and ensuring the reliability of the light-emitting diode.

[0087] Refer again Figure 6 and Figure 7 The first part of the electrode structure is located on the facing surface 101 when the electrode structure is formed by vapor deposition of metal material, and the second part is located on the back surface 102 when the electrode structure is formed by vapor deposition of metal material. In an optional example, when the first electrode 161 and the second electrode 162 of the light-emitting diode are simultaneously vapor-deposited, the first part 1611 of the first electrode 161 and the first part 1621 of the second electrode 162 located on the facing surface 101 are located on the same side of the electrode via, such as... Figure 4 As shown, the first portion 1611 of the first electrode 161 is located to the left of the first electrode through hole 1610, and the first portion 1621 of the second electrode 162 is also located to the left of the second electrode through hole 1620. It can be understood that the first portion 1611 of the first electrode 161 is located to the right of the first electrode through hole 1610, and the first portion 1621 of the second electrode 162 is also located to the right of the second electrode through hole 1620.

[0088] In an optional example, when the first electrode 161 and the second electrode 162 of the light-emitting diode are deposited, respectively, the first portion 1611 of the first electrode 161 and the first portion 1621 of the second electrode 162 located on the depositing surface 101 are located on opposite sides of the electrode via, such as... Figure 5 As shown, the first portion 1611 of the first electrode 161 is located to the left of the first electrode through hole 1610, and the first portion 1621 of the second electrode 162 is also located to the right of the second electrode through hole 1620. It can be understood that the first portion 1611 of the first electrode 161 is located to the right of the first electrode through hole 1610, and the first portion 1621 of the second electrode 162 is also located to the left of the second electrode through hole 1620.

[0089] Example 2

[0090] This embodiment provides a light-emitting device, such as... Figure 8 As shown, the light-emitting device 300 includes a circuit board 301 and at least one light-emitting unit 302 fixed to the circuit board 301. The light-emitting unit 302 includes the light-emitting diode provided in Embodiment 1 of this application. Because the light-emitting device includes the light-emitting diode provided in Embodiment 1, it has better reliability and good light extraction efficiency.

[0091] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A light-emitting diode, characterized in that, At least including: A semiconductor epitaxial stack includes a first semiconductor layer, an active layer, and a second semiconductor layer stacked sequentially; the semiconductor epitaxial stack has a first mesa and a second mesa, the surface of the first mesa is the exposed first semiconductor layer, the surface of the second mesa is the second semiconductor layer, and the first mesa is lower than the second mesa; Electrode through-holes are located above the first and second mezzanine surfaces; An electrode structure covers the sidewalls and bottom of the electrode through-hole, and the upper surface of the electrode structure has an opening; the electrode structure has a first part and a second part, and the boundary line between the first part and the second part is located in the bottom region of the opening; The metal continuity of the first part is superior to that of the second part.

2. The light-emitting diode according to claim 1, characterized in that, The dividing line between the first part and the second part is the bisector of the bottom region of the opening.

3. The light-emitting diode according to claim 1, characterized in that, The first part is located on the facing surface of the electrode through hole when the electrode structure is formed by vapor deposition of the metal material; the second part is located on the back surface of the electrode through hole when the electrode structure is formed by vapor deposition of the metal material.

4. The light-emitting diode according to claim 1, characterized in that, The metal material of the electrode structure extends from the sidewall of the electrode via to above the semiconductor epitaxial stack. The first part has a first sidewall above the semiconductor epitaxial stack, and the second part has a second sidewall above the semiconductor epitaxial stack. The angle between the first sidewall and the plane containing the surface of the semiconductor epitaxial stack is smaller than the angle between the second sidewall and the plane containing the surface of the semiconductor epitaxial stack.

5. The light-emitting diode according to claim 4, characterized in that, The first sidewall has a first segment connected to the semiconductor epitaxial stack and a second segment connected to the first segment, wherein the angle between the first segment and the plane containing the surface of the semiconductor epitaxial stack is smaller than the angle between the second segment and the plane containing the surface of the semiconductor epitaxial stack.

6. The light-emitting diode according to claim 1, characterized in that, The metal material of the electrode structure extends from the sidewall of the electrode via to the surface of the semiconductor epitaxial stack. The first part forms a first platform region above the semiconductor epitaxial stack, and the second part forms a second platform region above the semiconductor epitaxial stack. The width L1 of the first platform region is greater than the width L2 of the second platform region.

7. The light-emitting diode according to claim 6, characterized in that, The width L2 of the second platform region satisfies: 0≤L2≤0.5 μm.

8. The light-emitting diode according to claim 6, characterized in that, The width L1 of the first platform region satisfies: 0.5μm≤L1≤2μm.

9. The light-emitting diode according to claim 1, characterized in that, Projected onto the plane containing the surface of the semiconductor epitaxial stack, and within the bottom range of the electrode via, the projection profile of the opening in the first part and the bottom projection profile of the electrode via have a first minimum distance L3, and the projection profile of the opening in the second part and the bottom projection profile of the electrode via have a second minimum distance L4, where L3 > L4.

10. The light-emitting diode according to claim 9, characterized in that, The first minimum distance L3 satisfies: 0 < L3 ≤ 0.1 μm.

11. The light-emitting diode according to claim 9, characterized in that, The second minimum distance L4 satisfies: 0 ≤ L4 ≤ 0.05 μm.

12. The light-emitting diode according to claim 1, characterized in that, The coverage area S1 of the first part at the bottom of the electrode through hole is greater than the coverage area S2 of the second part at the bottom of the electrode through hole.

13. The light-emitting diode according to claim 1, characterized in that, The ratio of S1 to S2 is between 3:1 and 10:

1.

14. The light-emitting diode according to claim 1, characterized in that, The first part and the second part form a continuous structure.

15. The light-emitting diode according to claim 1, characterized in that, Also includes: An insulating protective layer covers the surfaces and sidewalls of the first mesa and the second mesa, as well as the sidewalls of the semiconductor epitaxial stack. A reflective layer is located above the insulating protective layer, and the electrode via penetrates both the reflective layer and the insulating protective layer.

16. The light-emitting diode according to claim 3, characterized in that, The side adjacent to the first and second platform is defined as the inner side of the light-emitting diode, and the side opposite to the first and second platform is defined as the outer side of the light-emitting diode. The facing side is the side closer to the outer side, and the back plating side is the side closer to the inner side.

17. A light-emitting device, characterized in that, It includes a circuit board and a light-emitting element disposed on the circuit board, wherein the light-emitting element comprises a light-emitting diode as described in any one of claims 1 to 16.

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