Light emitting diode and light emitting device

Abstract

The invention discloses a light-emitting diode and a light-emitting device, and the light-emitting diode comprises a semiconductor epitaxial laminated layer which is provided with a first surface and a second surface which are opposite, and comprises a first semiconductor structure, an active layer, a second semiconductor structure and a third semiconductor layer; a concave part and a non-concave part are formed on one side, far away from the second semiconductor structure, of the third semiconductor layer; the ohmic contact layer is arranged at the non-concave part of a part of the third semiconductor layer; the light-transmitting dielectric layer is arranged on one side, far away from the semiconductor epitaxial laminated layer, of the ohmic contact layer and is provided with a plurality of openings penetrating through the light-transmitting dielectric layer; the reflecting layer is arranged on the light-transmitting dielectric layer and is filled in the opening; the light emitting diode is characterized in that the non-concave part of the third semiconductor layer has a first area, the second semiconductor structure has a second area, and the ratio of the first area to the second area is 0.7-1.0; the ohmic contact layer has a third area, and the ratio of the third area to the second area is 0.5-1.

Description

Light-emitting diode and light-emitting device Technical Field

[0001] The invention relates to a light emitting diode, belonging to the technical field of semiconductor optoelectronic devices. Background Art

[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, which is responsible for the light-emitting properties of the diode. LEDs offer advantages such as high luminous intensity, high efficiency, compact size, and long life, making them considered one of the most promising light sources. LEDs have been widely used in lighting, surveillance and control, high-definition broadcasting, high-end cinemas, office displays, interactive conferences, and virtual reality. However, LEDs still face the problem of poor current spreading, which in turn results in low luminous efficiency.

[0003] It should be noted that the information disclosed in this background technology section is only intended to increase understanding of the overall background of the present invention, and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art. Technical Solutions

[0004] To address the aforementioned issues and improve the uniformity of current spreading in a light-emitting diode (LED), thereby enhancing the brightness and luminous efficiency of the LED, the present invention provides a light-emitting diode (LED), comprising: a semiconductor epitaxial stack having opposing first and second surfaces, comprising a first semiconductor structure, an active layer, a second semiconductor structure, and a third semiconductor layer; the third semiconductor layer having a recess and a non-recessed portion formed on a side remote from the second semiconductor structure; an ohmic contact layer disposed in a portion of the non-recessed portion of the third semiconductor layer; a light-transmitting dielectric layer disposed on a side of the ohmic contact layer remote from the semiconductor epitaxial stack, having a plurality of openings extending through the light-transmitting dielectric layer; and a reflective layer disposed on the light-transmitting dielectric layer, filling the openings, and connecting to the ohmic contact layer. The LED is characterized in that: the non-recessed portion of the third semiconductor layer has a first area, the second semiconductor structure has a second area, and a ratio of the first area to the second area is between 0.7 and 1.0; and the ohmic contact layer has a third area, and a ratio of the third area to the second area is between 0.5 and 1.

[0005] The present invention further provides a light-emitting device, which includes the aforementioned light-emitting diode. Beneficial effects

[0006] By optimizing the design of the third semiconductor layer and the ohmic contact layer, the present invention can improve the uniformity of the current expansion of the light-emitting diode, reduce the voltage of the light-emitting diode, and maximize the mirror reflection area, thereby improving the luminous brightness and luminous efficiency of the light-emitting diode.

[0007] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In addition, the accompanying drawings are for description only and are not drawn to scale.

[0009] FIG1 is a schematic structural diagram of the light emitting diode mentioned in Example 1 of the present invention.

[0010] FIG2 is a schematic diagram of an orthographic projection of the light emitting diode mentioned in Example 1 of the present invention on the semiconductor epitaxial stack.

[0011] FIG3 is a schematic structural diagram of the light emitting diode mentioned in Example 2 of the present invention.

[0012] FIG4 is a schematic structural diagram of the light emitting diode mentioned in Example 3 of the present invention.

[0013] 5 to 10 are schematic structural diagrams of the light emitting diode manufacturing process mentioned in Example 1 of the present invention.

[0014] FIG11 is a schematic structural diagram of the light-emitting device mentioned in Example 5 of the present invention.

[0015] Explanation of component numbers in the figure: 10: growth substrate; 100: base plate; 101: metal bonding layer; 102: reflective layer; 103: translucent dielectric layer; 104: ohmic contact layer; 105: third semiconductor layer; 106: second semiconductor structure; 107: active layer; 108: first semiconductor structure; 1091: main electrode of the first electrode; 1092: extended electrode of the first electrode; 110: second electrode; 111: insulating layer; V1: recess in the third semiconductor layer; V2: opening in the translucent dielectric layer; light-emitting device: 300; light-emitting diode: 1. Modes for Carrying Out the Invention

[0016] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0017] It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0018] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. Example

[0019] Please refer to Figures 1 and 2. Figure 1 is a schematic diagram of the structure of a light-emitting diode provided by the first embodiment of the present invention, and Figure 2 is a schematic diagram of the orthographic projection of the light-emitting diode provided by the first embodiment of the present invention on a semiconductor epitaxial stack. To achieve at least one of the aforementioned advantages or other advantages, the first embodiment of the present invention provides a light-emitting diode. As shown in the schematic diagram of the structure in Figure 1, it includes the following stacked layers: 100: substrate; 101: metal bonding layer; 102: reflective layer; 103: light-transmitting dielectric layer; 104: ohmic contact layer; 105: third semiconductor layer; 106: second semiconductor structure; 107: active layer; 108: first semiconductor structure; 1091: main electrode of the first electrode; 1092: extension electrode of the first electrode; 110: second electrode; 111: insulating layer.

[0020] The LED can have any conceivable shape, such as a polygon, a circle, or an irregular shape. In this embodiment, the LED has a quadrilateral shape, including a first side E1, a second side E2, a third side E3, and a fourth side E4. The first side E1 and the third side E3 connect the second side E2 and the fourth side E4. The first side E1 and the third side E3 are opposite and may be parallel to each other, while the second side E2 and the fourth side E4 are opposite and may be parallel to each other, as shown in FIG. 2 .

[0021] In one embodiment, the light-emitting diode includes a first electrode, and the first electrode includes one or more main electrodes 1091 and multiple extended electrodes 1092. The main electrode 1091 can be connected to one or more extended electrodes 1092. In this embodiment, the light-emitting diode includes two main electrodes 1091, and some of the extended electrodes 1092 are parallel to the second side E2 and the fourth side E4, and some of the extended electrodes 1092 are parallel to the first side E1 and the third side E3, as shown in Figure 2. The main electrode 1091 is mainly used for external wiring during packaging. The main electrode 1091 can be designed into different shapes according to actual wiring needs, such as cylindrical, square or other polygonal shapes. The extended electrode 1092 can be formed in a predetermined pattern shape, and the extended electrode can have various shapes, such as strips.

[0022] The light-emitting diode includes a substrate 100, which is a conductive substrate. The conductive substrate can be silicon, silicon carbide, or a metal substrate. The metal substrate is preferably a copper, tungsten, copper tungsten, or molybdenum substrate. In order to support the semiconductor epitaxial stack with sufficient mechanical strength, the thickness of the substrate 100 is preferably greater than 50 μm. In addition, in order to facilitate mechanical processing of the substrate 100 after bonding the semiconductor epitaxial stack, the thickness of the substrate 100 is preferably no more than 300 μm. In this embodiment, the substrate 100 is preferably a silicon substrate or a CuW substrate.

[0023] The light-emitting diode includes a semiconductor epitaxial stack having a first surface, a second surface opposite the first surface, and sidewalls connecting the first and second surfaces. The semiconductor epitaxial stack is grown by MOCVD or other growth methods and is made of a semiconductor material capable of providing conventional radiation, such as ultraviolet, blue, green, yellow, red, or infrared light. Specifically, it can be a material with a wavelength of 200 to 950 nm, such as a common nitride, specifically a gallium nitride-based semiconductor epitaxial stack doped with elements such as aluminum and indium, which primarily provides radiation in the 200 to 550 nm band; or a common aluminum gallium indium phosphide-based or aluminum gallium arsenide-based semiconductor epitaxial stack, which primarily provides radiation in the 550 to 950 nm band.

[0024] The semiconductor epitaxial stack primarily includes a first semiconductor structure 108, a second semiconductor structure 106, and an active layer 107 located between the first and second semiconductor structures 108 and 106. The first and second semiconductor structures 108 and 106 can be n-type doped or p-type doped to provide at least electrons or holes, respectively. The first and second semiconductor structures 108 and 106 can be single-layer or multi-layer structures. The n-type semiconductor layer can be doped with n-type dopants such as Si, Ge, or Sn, and the p-type semiconductor layer can be doped with p-type dopants such as Mg, Zn, Ca, Sr, or Ba. The first semiconductor structure 108, active layer 107, and second semiconductor structure 106 can be made of materials such as aluminum gallium indium nitride, gallium nitride, aluminum gallium nitride, aluminum indium phosphide, aluminum gallium indium phosphide, gallium arsenide, or aluminum gallium arsenide. The active layer 107 is a region that provides light radiation for electron and hole recombination. Different materials can be selected depending on the emission wavelength. The active layer 107 can be a periodic structure of single quantum wells or multiple quantum wells. Light of different wavelengths can be radiated by adjusting the composition ratio of semiconductor materials in the active layer 107. In this embodiment, the semiconductor epitaxial stack is preferably composed of AlGaInP-based or GaAs-based materials, and the semiconductor epitaxial stack radiates light with a wavelength of 550-950 nm.

[0025] In order to improve the current scalability of the light-emitting diode, a third semiconductor layer 105 is provided on the second semiconductor structure 106. The material of the third semiconductor layer 105 can be GaP, AlGaAs, AlGaInP, etc. In this embodiment, the material of the third semiconductor layer 105 is preferably GaP, and the thickness is 0.02-1.5 μm, and more preferably the thickness of the third semiconductor layer 105 is 0.02-0.8 μm. The doping concentration of the third semiconductor layer 105 is preferably 5E17-5E19 / cm 3 .

[0026] In some embodiments, in order to reduce the light absorption of the third semiconductor layer 105, a recess V1 and a non-recess are formed on the side of the third semiconductor layer 105 away from the second semiconductor structure 106. The non-recesses can be formed into multiple independent ones, and the recesses are continuous and surround the multiple independent non-recesses. The top surfaces of the multiple non-recesses can be circular, semicircular, triangular, pentagonal, hexagonal, etc.; or the recesses can be formed into multiple ones and are continuously surrounded by non-recesses to form a structure of multiple independent recesses. The top surfaces of the multiple recesses can be circular, semicircular, triangular, pentagonal, hexagonal, etc. In this embodiment, the width of the recess V1 is preferably 4~20μm, preferably 6~13μm. The shape of the recess is circular, but this embodiment is not limited to this.

[0027] The non-recessed portion V1 of the third semiconductor layer 105 has a first area, and the second semiconductor structure 106 has a second area. The ratio of the first area to the second area is 0.7~1.0. Preferably, the ratio of the first area to the second area is greater than 0.75, and more preferably greater than 0.8. By setting the ratio of the first area to the second area within this range, the uniformity of the current expansion of the light-emitting diode can be improved to obtain a light-emitting diode with a lower operating voltage.

[0028] In some optional embodiments, the recess V1 formed in the third semiconductor layer 105 penetrates the third semiconductor layer 105. Here, penetration means that the recess in the third semiconductor layer 105 is formed so that a portion of the third semiconductor layer 105 is completely removed along the depth direction, as shown in FIG1 . In some optional embodiments, the recess in the third semiconductor layer 105 does not penetrate the third semiconductor layer 105, that is, the recess in the third semiconductor layer 105 is formed so that a portion of the third semiconductor layer 105 is thinned along the depth direction. The thinning or removal process can be achieved by conventional dry etching in a well-known process. The recess in the third semiconductor layer 105 is formed non-penetratingly. Specifically, the depth of the recess into the third semiconductor layer 105 is greater than 0, but lower than the depth of the non-recessed portion of the third semiconductor layer 105. Since the third semiconductor layer 105 has the problem of light absorption, the recess formed in the third semiconductor layer 105 can limit the direction of current and reduce the light absorption of the third semiconductor layer 105, thereby improving the brightness of the light-emitting diode.

[0029] As shown in FIG1 , in some embodiments, the first orthographic projection of the recess V1 formed by the third semiconductor layer on the horizontal plane of the semiconductor epitaxial stack is located on both sides of the second orthographic projection of the extended electrode of the first electrode on the horizontal plane of the semiconductor epitaxial stack. That is, the first orthographic projection of the recess V1 formed by the third semiconductor layer on the horizontal plane of the semiconductor epitaxial stack and the second orthographic projection of the extended electrode of the first electrode on the horizontal plane of the semiconductor epitaxial stack do not overlap. By arranging the first orthographic projection of the recess V1 formed by the third semiconductor layer on the horizontal plane of the semiconductor epitaxial stack on both sides of the second orthographic projection of the extended electrode 1092 of the first electrode on the horizontal plane of the semiconductor epitaxial stack, the current flow of the light-emitting diode can be guided, the uniformity of the current spread of the light-emitting diode can be improved, and the operating voltage of the light-emitting diode can be reduced.

[0030] An ohmic contact layer 104 is provided in the non-recessed portion of the third semiconductor layer 105, and the ohmic contact layer 104 is electrically connected to the third semiconductor layer 105. The ohmic contact layer 104 is a strip-shaped structure, and the fourth orthographic projection of the ohmic contact layer 104 on the horizontal plane of the semiconductor epitaxial stack is located between the second orthographic projections of the extended electrodes of the adjacent first electrodes on the horizontal plane of the semiconductor epitaxial stack. The fourth orthographic projection of the ohmic contact layer on the semiconductor epitaxial stack and the second orthographic projection of the extended electrodes of the first electrode on the horizontal plane of the semiconductor epitaxial stack do not overlap with each other, and are distributed in a cross-section. By providing the ohmic contact layer with a strip-shaped structure and providing it between the second orthographic projections of the extended electrodes of the first electrode on the horizontal plane of the semiconductor epitaxial stack, it is possible to ensure that the ohmic contact layer forms a good ohmic contact with the third semiconductor layer, while controlling the direction of the current and improving the uniformity of the current expansion of the light-emitting diode.

[0031] In some optional embodiments, the ohmic contact layer 104 has a third area, and the ratio of the third area to the second area is between 0.5 and 1. More preferably, the ratio of the third area to the first area is between 0.7 and 0.9. By setting the distribution form and the area ratio of the ohmic contact layer, it can be ensured that the ohmic contact layer in the light-emitting diode has sufficient ohmic contact with the semiconductor epitaxial stack, so as to achieve a lower operating voltage and improve the luminous efficiency of the light-emitting diode.

[0032] The ohmic contact layer 104 is made of a transparent conductive material. The transparent conductive material 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 disclosed embodiment is not limited thereto. In this embodiment, the ohmic contact layer is preferably indium tin oxide (ITO).

[0033] The metal bonding layer 101 is a metal material used when bonding the semiconductor epitaxial stack to the substrate 100, such as metal elements such as gold, tin, titanium, tungsten, nickel, platinum, and indium. The metal bonding layer 101 can be a single-layer structure or a multi-layer structure, and can be a combination of multiple materials.

[0034] The reflective layer 102 is located above the metal bonding layer 101 and closer to the semiconductor epitaxial stack. The reflective layer 102 has a reflectivity of over 70% and is formed from a metal or alloy containing at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Ti, Cr, Zn, Pt, Au, and Hf. In this embodiment, the reflective layer 102 is preferably made of Au or Ag. The reflective layer 102 is capable of reflecting light radiated from the semiconductor epitaxial stack toward the substrate 100, returning it to the semiconductor epitaxial stack and radiating it out the light-emitting side. The light-emitting surface of the light-emitting diode is located on the side of the first semiconductor structure 108 away from the active layer 107.

[0035] The transparent dielectric layer 103 is located on the side of the third semiconductor layer 105 away from the active layer 107, and between the semiconductor epitaxial stack and the reflective layer 102. The transparent dielectric layer 103 has a plurality of openings V2 extending through the transparent dielectric layer 103. The openings V2 in the transparent dielectric layer 103 are located above the ohmic contact layer 104, and the orthographic projections of the openings V2 on the horizontal plane of the semiconductor epitaxial stack are located within the fourth orthographic projection of the ohmic contact layer on the horizontal plane of the semiconductor epitaxial stack. The openings V2 form conductive vias, which are filled with the reflective layer 102 and electrically connected to the ohmic contact layer 104. The sidewalls of the openings V1 in the transparent dielectric layer 103 can be inclined or vertical, and the angle between the sidewalls and the second surface is θ1, which ranges from 20° to 90°. Preferably, θ1 ranges from 30° to 70°; more preferably, it ranges from 40° to 60°. The sidewalls of the opening V1 in the transparent dielectric layer 103 are inclined, facilitating coverage of the reflective layer 103 on the sidewalls of the opening. Furthermore, the inclined sidewalls reflect light emitted from the semiconductor epitaxial stack toward the light-emitting surface. In this embodiment, the angle between the sidewalls and the second surface is 90°, but the disclosed embodiments are not limited thereto.

[0036] The light-transmitting dielectric layer 103 is made of fluoride, oxide or nitride, such as ZnO, SiO2, SiO x 、SiO x N y 、Si3N4、Al2O3、TiO x, MgF, or GaF. The transparent dielectric layer 103 is used to reflect light radiation from the active layer 107 back to the semiconductor epitaxial stack or the sidewall. Therefore, the transparent dielectric layer in direct contact with the semiconductor epitaxial stack is preferably made of a low refractive index material to increase the probability of light radiation being reflected when passing through the semiconductor epitaxial stack to the surface of the transparent dielectric layer 103. Its refractive index is preferably below 1.5, such as silicon oxide. The thickness of the transparent dielectric layer 103 is preferably greater than 50nm, for example, 50-500nm, more preferably 70-500nm, or more preferably 80-500nm. The transmittance of the transparent dielectric layer 104 is at least 70%, preferably greater than 80%, and more preferably greater than 90%.

[0037] More preferably, the light-transmitting dielectric layer 103 is a single layer or multiple layers of different materials, or is formed by repeatedly stacking two of the above-mentioned insulating layer materials with different refractive indices. More preferably, the optical thickness of the light-transmitting dielectric layer 103 is in the range of an integer multiple of (light-emitting wavelength / 4). A series of openings V2 are formed inside the light-transmitting dielectric layer 103, penetrating the light-transmitting dielectric layer 103, as shown in Figure 1, to form a plurality of conductive vias. The horizontal cross-sectional shape of the openings V2 can be circular, elliptical, or polygonal. The horizontal width of the light-transmitting dielectric layer 103 is 2 to 10 μm, more preferably 2 to 6 μm. By reducing the opening size of the light-transmitting dielectric layer 103, the ODR mirror reflection area can be increased, thereby improving the luminous efficiency of the light-emitting diode. The opening of the light-transmitting dielectric layer has a fourth area, and the ratio of the fourth area to the second area is between 0.1 and 0.5. More preferably, the ratio of the fourth area to the second area is between 0.1 and 0.3. By setting the ratio of the fourth area to the second area within this range, the ODR mirror reflection area can be increased and the luminous efficiency of the light-emitting diode can be improved.

[0038] The reflective layer 102 and the light-transmitting dielectric layer 103 form an ODR reflective structure, which returns light radiated from the semiconductor epitaxial stack toward the substrate 100 to the semiconductor epitaxial stack and radiates it out from the light-emitting side, thereby improving light extraction efficiency.

[0039] The light-emitting diode further includes a second electrode 110. In this embodiment, the second electrode 110 is formed entirely on the back side of the substrate 100. The substrate 100 in this embodiment is a conductive support substrate. The first electrode 109 and the second electrode 110 are formed on opposite sides of the substrate 100 to ensure a vertical current flow through the semiconductor epitaxial stack and provide a uniform current density. The first electrode 109 and the second electrode 110 are preferably made of a metal material.

[0040] The light emitting diode further includes an insulating layer 111 . The insulating layer 111 covers the upper surface and sidewalls of the semiconductor epitaxial stack, thereby protecting the light emitting diode from interference from water vapor and improving the reliability of the light emitting diode.

[0041] In this embodiment, the optimized design of the third semiconductor layer and the ohmic contact layer can improve the uniformity of the current expansion of the light-emitting diode, and maximize the mirror reflection area while ensuring a low voltage of the light-emitting diode, thereby improving the brightness and luminous efficiency of the light-emitting diode. Example

[0042] Figure 3 is a schematic diagram of the structure of a light-emitting diode according to another embodiment of the present invention. Compared to the light-emitting diode of Figure 1 in Example 1, the first orthographic projection of the recess in this embodiment is also located on both sides of the third orthographic projection of the main electrode of the first electrode on the horizontal plane of the semiconductor epitaxial stack. This arrangement can control the direction of the current in the main electrode, further improving the uniformity of the current spread of the light-emitting diode, reducing the operating voltage of the light-emitting diode, and thus improving the luminous efficiency of the light-emitting diode.

[0043] In this embodiment, the recess of the third semiconductor layer is arranged so that the first orthographic projection of the semiconductor epitaxial stack is located on both sides of the second orthographic projection and the third orthographic projection of the extended electrode and the main electrode of the first electrode on the horizontal plane of the semiconductor epitaxial stack. By setting in this manner, the direction of the current in the light-emitting diode can be controlled and the uniformity of the current expansion of the light-emitting diode can be improved; at the same time, by adjusting the area ratio of the ohmic contact layer, it can be ensured that the semiconductor epitaxial stack and the ohmic contact layer form a good ohmic contact, thereby reducing the voltage and improving the luminous brightness and luminous efficiency of the light-emitting diode. Example

[0044] Figure 4 is a schematic diagram of the structure of a light-emitting diode according to another embodiment of the present invention. Compared to the light-emitting diode of Figure 1 in Example 1, the first orthographic projection of the recess in this embodiment is also located within the third orthographic projection of the main electrode of the first electrode on the horizontal plane of the semiconductor epitaxial stack. This arrangement reduces light absorption by the third semiconductor layer and controls the direction of current flow, thereby improving the brightness and luminous efficiency of the light-emitting diode.

[0045] In this embodiment, the recess of the third semiconductor layer is arranged so that the first orthographic projection of the extended electrode of the first electrode on the horizontal plane of the semiconductor epitaxial stack is located on both sides of the second orthographic projection of the extended electrode of the first electrode on the horizontal plane of the semiconductor epitaxial stack and the main electrode is within the third orthographic projection of the horizontal plane of the semiconductor epitaxial stack. By the arrangement in the above manner, the light absorption of the third semiconductor layer can be reduced, the direction of the current of the light-emitting diode can be controlled, and the uniformity of the current expansion of the light-emitting diode can be improved; at the same time, by adjusting the area ratio of the ohmic contact layer, it can be ensured that the semiconductor epitaxial stack and the ohmic contact layer form a good ohmic contact, thereby reducing the voltage and improving the luminous brightness and luminous efficiency of the light-emitting diode. Example

[0046] The manufacturing process of the light emitting diode of the above-mentioned embodiment 1 is described in detail below.

[0047] As shown in FIG. 5 , a semiconductor epitaxial stack is first provided, comprising a first semiconductor structure 108 , an active layer 107 , a second semiconductor structure 106 and a third semiconductor layer 105 .

[0048] The process specifically includes the following steps: providing a growth substrate 10, preferably a gallium arsenide substrate, and epitaxially growing a semiconductor epitaxial stack on the growth substrate 10 using an epitaxial process such as MOCVD. The semiconductor epitaxial stack includes a first semiconductor structure 108, an active layer 107, a second semiconductor structure 106, and a third semiconductor layer 105. When the first semiconductor structure 108 is an n-type semiconductor, the second semiconductor structure 106 can be a p-type semiconductor with a different electrical property. Conversely, when the first semiconductor structure 108 is a p-type semiconductor, the second semiconductor structure 106 can be an n-type semiconductor with a different electrical property. The active layer 107 can be a neutral, p-type, or n-type semiconductor. When current is applied through the semiconductor epitaxial stack, the active layer 107 is excited to emit light. In this embodiment, the second semiconductor structure 106 and the third semiconductor layer 105 are preferably p-type semiconductor layers. The semiconductor epitaxial stack is preferably made of AlGaInP-based or GaAs-based materials, and the active layer 107 radiates red or infrared light.

[0049] As shown in FIG6 , an ohmic contact layer 104 is then evaporated on the surface of the third semiconductor layer 105. A photoresist pattern is formed by mask development, and etching is performed to form a patterned ohmic contact layer 104. The third semiconductor layer 105 is then etched using a conventional inductively coupled plasma etcher to form recessed and non-recessed portions of the third semiconductor layer 105. In this embodiment, the ohmic contact layer 104 is made of ITO.

[0050] As shown in FIG. 7 , a transparent dielectric layer structure 103 is then formed in the concave and non-concave portions of the third semiconductor layer 105 by PECVD, ALD, E-beam, or other methods.

[0051] As shown in FIG8 , a photoresist pattern is then formed by developing a photomask, exposing an opening region for forming the light-transmitting dielectric layer structure 103. The light-transmitting dielectric layer 103 is then etched to form a through hole V1 in the light-transmitting dielectric layer structure 103. A reflective layer 102 is then formed in the through hole V1 of the light-transmitting dielectric layer 103 and on a side away from the light-emitting surface.

[0052] Then, a metal bonding layer 101 is provided on one side of the reflective layer 102 and bonded to the substrate 100 through a bonding process; then, the growth substrate 10 is removed by a wet etching process to obtain the structure shown in FIG. 9 .

[0053] Finally, a main electrode 1091 and an extended electrode 1092 of the first electrode are formed on the first conductive semiconductor layer 106, and a second electrode 110 is formed on the back side of the substrate 100 to obtain a light-emitting diode as shown in Figure 10. The first orthographic projection of the translucent dielectric layer concave on the horizontal plane of the semiconductor epitaxial stack is located on both sides of the second orthographic projection of the extended electrode 1092 of the first electrode on the horizontal plane of the semiconductor epitaxial stack, which can control the direction of the current, improve the uniformity of the current expansion of the light-emitting diode, and improve the luminous brightness and luminous efficiency of the light-emitting diode.

[0054] In some optional embodiments, in order to further improve the efficiency of light radiated from the active layer 108 emerging from the light emitting surface, a roughened structure can be formed on the surface of the first semiconductor structure through an etching process, and then an insulating layer 111 is covered on the upper surface and side walls of the semiconductor epitaxial stack to obtain the light emitting diode as described in Figure 1.

[0055] The light-emitting diode obtained by the preparation method in this embodiment can improve the uniformity of the current expansion of the light-emitting diode, maximize the mirror reflection area while ensuring that the voltage of the light-emitting diode is low, thereby improving the luminous brightness and luminous efficiency of the light-emitting diode. Example

[0056] This embodiment provides a light emitting device 300 , please refer to FIG11 . The light emitting device 300 includes a plurality of light emitting diodes arranged in an array as in any of the aforementioned embodiments. FIG11 shows a portion of the light emitting diodes 1 in an enlarged schematic manner.

[0057] In this embodiment, the light emitting device 300 may be a plant lighting device, a stage light, a projector, or a display screen.

[0058] As the light emitting diodes of the aforementioned embodiments are included, the light emitting device 300 has the advantages brought by the light emitting diodes of the aforementioned embodiments.

[0059] It should be noted that the above embodiments are only used to illustrate the present invention, and are not used to limit the present invention. Those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the present invention. The scope of patent protection of the present invention should be limited to the scope of the claims.

Claims

1. Light emitting diodes, including: A semiconductor epitaxial stack having a first surface and a second surface opposite to each other, comprising a first semiconductor structure, an active layer, a second semiconductor structure and a third semiconductor layer; The third semiconductor layer forms a concave portion and a non-concave portion on a side away from the second semiconductor structure; An ohmic contact layer is disposed at a non-recessed portion of the third semiconductor layer; A light-transmitting dielectric layer is disposed on a side of the ohmic contact layer away from the semiconductor epitaxial stack, and has a plurality of openings penetrating the light-transmitting dielectric layer; A reflective layer, disposed on the light-transmitting dielectric layer, filled in the opening, and connected to the ohmic contact layer; It is characterized in that: the non-recessed portion of the third semiconductor layer has a first area, the second semiconductor structure has a second area, and the ratio of the first area to the second area is between 0.7 and 1.0; the ohmic contact layer has a third area, and the ratio of the third area to the second area is between 0.5 and 1.

2. The light emitting diode according to claim 1, characterized in that: The ratio of the third area to the second area is between 0.7 and 0.

9.

3. The light emitting diode according to claim 1, characterized in that: The width of the concave portion is 4 to 20 μm.

4. The light emitting diode according to claim 3, characterized in that: The width of the concave portion is 6 to 13 μm.

5. The light emitting diode according to claim 1, characterized in that: The opening of the light-transmitting dielectric layer has a fourth area, and a ratio of the fourth area to the second area is between 0.1 and 0.

5.

6. The light emitting diode according to claim 1, characterized in that: The light-transmitting dielectric layer is a single-layer or multi-layer structure, and is composed of at least one material selected from nitride, oxide or fluoride.

7. The light emitting diode according to claim 1, characterized in that: The thickness of the light-transmitting dielectric layer is greater than 500 Å.

8. The light emitting diode according to claim 1, characterized in that: The sidewall of the opening of the light-transmitting dielectric layer is inclined, and an angle between the sidewall and the second surface is θ1, and the range of θ1 is 20° to 90°.

9. The light emitting diode according to claim 8, characterized in that: The range of θ1 is 30°~70°.

10. The light emitting diode according to claim 1, characterized in that: The light emitting diode comprises a first electrode located on the first semiconductor structure. The first electrode comprises a main electrode and a plurality of extended electrodes. The plurality of extended electrodes are connected to the main electrode.

11. The light emitting diode according to claim 10, characterized in that; A first orthographic projection of the recess on a horizontal plane of the semiconductor epitaxial stack is at least located on two sides of a second orthographic projection of the extension electrode on the horizontal plane of the semiconductor epitaxial stack.

12. The light emitting diode according to claim 11, characterized in that: The first orthographic projection and the second orthographic projection do not overlap each other.

13. The light emitting diode according to claim 10, characterized in that: The first orthographic projection of the recess on the horizontal plane of the semiconductor epitaxial stack is located on both sides of the third orthographic projection of the main electrode on the horizontal plane of the semiconductor epitaxial stack.

14. The light emitting diode according to claim 10, characterized in that: The fourth orthographic projection of the ohmic contact layer on the horizontal plane of the semiconductor epitaxial stack is at least located between the second orthographic projections of the two adjacent extension electrodes on the horizontal plane of the semiconductor epitaxial stack.

15. The light emitting diode according to claim 14, characterized in that: The fourth orthographic projection and the second orthographic projection do not overlap each other.

16. The light emitting diode according to claim 1, characterized in that: The ohmic contact layer is a stripe structure.

17. The light emitting diode according to claim 1, characterized in that: The ohmic contact layer is a transparent conductive layer.

18. The light emitting diode according to claim 17, characterized in that: The ohmic contact layer is ZnO, In2O3, SnO2, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), GZO (Gallium-doped Zinc Oxide) or any combination thereof.

19. The light emitting diode according to claim 1, characterized in that: The light emitting diode radiates light with a wavelength of 550-950 nm.

20. A light emitting device, characterized in that: The light-emitting device comprises the light-emitting diode according to any one of claims 1 to 19.

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