Micro light emitting element and method for manufacturing the same

Abstract

The application provides a micro light-emitting element and a preparation method thereof. The micro light-emitting element comprises a substrate and a plurality of LED chips on the surface of the substrate. The substrate has a plurality of electrode connecting components distributed at intervals. The LED chips comprise vertical structure LED chips. The vertical structure LED chips are horizontally arranged on the surface of the substrate, and the two polar electrodes of the vertical structure LED chips are connected with the electrode connecting components, respectively. Meanwhile, the remaining light-emitting surfaces are shielded so that light is emitted through only one surface, thereby realizing a good light-emitting appearance, which is in a Lambertian distribution. In addition, the plurality of LED chips on the surface of the substrate can be integrated by wafer-level bonding in the chip manufacturing process, thereby avoiding multiple mass transfer in the traditional light mixing process, realizing full colorization, and breaking through the size limitation of the existing chip technology, so that the light-emitting unit can be made smaller.

Description

Technical Field

[0001] This invention relates to the field of light-emitting diodes, and more particularly to a micro light-emitting element and its fabrication method. Background Technology

[0002] Micro-component technology refers to the high-density integration of tiny arrays of components on a substrate. Currently, Mini / Micro-LED technology is becoming a hot research topic, with industry eagerly anticipating the market entry of high-quality micro-component products. High-quality Mini / Micro-LED products will have a profound impact on existing traditional display products such as LCD / OLED displays.

[0003] As the display industry develops, the requirements for panel power consumption and display effect are becoming increasingly stringent. Compared with OLED and LCD displays, LED direct display can effectively improve display brightness and reduce power consumption while ensuring lifespan and response speed. However, LED direct display faces the limit of miniaturization. Although the industry has invested a lot of resources in developing Mini / Micro-LED chips, the mass production of miniaturized chips, especially MICRO chips, is still difficult due to limitations in equipment capabilities and the physical limitations of chip design.

[0004] Existing microchip technology largely follows the design principles of traditional chip technology, typically bonding horizontally structured LED chips to a substrate. The resulting chips have five light-emitting surfaces (one front and four side surfaces), but the actual light-collecting direction is perpendicular to the epitaxial stack direction, meaning front-side light emission is used. However, as... Figure 1 As shown, with chip miniaturization, the proportion of side-emitting light increases dramatically. Since this side-emitting light is not effectively utilized, it directly affects the chip's light emission morphology. Furthermore, traditional microchips, limited by their dual-electrode structure, sacrifice some of the light-emitting area during fabrication. Additionally, the electrode arrangement limits chip size, and further reduction in chip size carries the risk of electrode short circuits. Thus, the fabrication of micro-light-emitting elements faces significant challenges.

[0005] In view of this, the inventors have specifically designed a micro light-emitting element and its preparation method, which leads to this invention. Summary of the Invention

[0006] The purpose of this invention is to provide a micro light-emitting element and its preparation method, so as to solve the problems of complex manufacturing process and limited size miniaturization of micro light-emitting elements.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A micro light-emitting element includes a substrate and a plurality of LED chips located on the surface of the substrate; wherein the substrate has a plurality of spaced-apart electrode connection components; the LED chips include vertical structure LED chips; the vertical structure LED chips lie horizontally on the surface of the substrate, and the two polar electrodes of the vertical structure LED chips are respectively connected to the electrode connection components.

[0009] Preferably, the surface of the vertical LED chip facing away from the substrate is the light-emitting surface, and a reflector is provided on the non-light-emitting surface of the LED chip.

[0010] Preferably, the reflector is in insulating contact with the non-light-emitting surface of the LED chip.

[0011] Preferably, the reflector includes a DBR structure and an ODR structure.

[0012] Preferably, each of the electrode connection components is arranged side by side on the surface of the substrate.

[0013] Preferably, the vertical structure LED chip includes a red LED chip, a green LED chip, and a blue LED chip; and the red LED chip, green LED chip, and blue LED chip are arranged side by side on the surface of the substrate to form a light-emitting unit with red, green, and blue primary colors.

[0014] Preferably, adjacent LED chips are spaced apart from each other.

[0015] Preferably, two adjacent LED chips are bonded together to form a single unit through an insulating material layer.

[0016] Preferably, the micro-light-emitting element includes a Mini-LED chip or a Micro-LED chip.

[0017] Preferably, the vertical structure LED chip includes a second type semiconductor layer, an active region, a first type semiconductor layer, and a first electrode, which are sequentially stacked on the surface of the electrode substrate.

[0018] The present invention also provides a method for fabricating a micro light-emitting element, the method comprising the following steps:

[0019] S01, Provide a growth substrate;

[0020] S02. An epitaxial stack is grown on the surface of the growth substrate, the epitaxial stack comprising a first type semiconductor layer, an active region and a second type semiconductor layer grown sequentially.

[0021] S03. Etch along the surface of the epitaxial stack to the surface of the growth substrate to form a plurality of epitaxial units arranged at intervals between each other through channels;

[0022] S04. An electrode substrate is provided, and the electrode substrate is integrally formed with the epitaxial stack on the surface of the epitaxial stack by a bonding process;

[0023] S05. Peel off the growth substrate to expose the first type of semiconductor layer;

[0024] S06. A first electrode is formed on the exposed surface of the first type of semiconductor layer;

[0025] S07. A plurality of vertical structure LED chips are formed by cutting, wherein the electrode substrate serves as the second electrode of the vertical structure LED chip;

[0026] S08. A substrate is provided, the substrate having a plurality of spaced-apart electrode connection components;

[0027] S09. The vertical structure LED chip is laid horizontally on the surface of the substrate, and the two polar electrodes of the vertical structure LED chip are respectively connected to the electrode connection component.

[0028] S10. Repeat step S09 to make the substrate have a plurality of vertical structure LED chips, with adjacent vertical structure LED chips spaced apart from each other.

[0029] Preferably, the surface of the vertical LED chip facing away from the substrate is the light-emitting surface; and a reflector is provided on the non-light-emitting surface of the LED chip.

[0030] Preferably, red LED chips, green LED chips, and blue LED chips are obtained respectively by the preparation method; and the red LED chips, green LED chips, and blue LED chips are arranged side by side on the surface of the substrate to form a light-emitting unit with red, green, and blue primary colors.

[0031] The present invention also provides another method for fabricating a micro light-emitting element, the method comprising the following steps:

[0032] S01, Provide a growth substrate;

[0033] S02. An epitaxial stack is grown on the surface of the growth substrate, the epitaxial stack comprising a first type semiconductor layer, an active region and a second type semiconductor layer grown sequentially.

[0034] S03. Etch along the surface of the epitaxial stack to the surface of the growth substrate to form a plurality of epitaxial units arranged at intervals between each other through channels;

[0035] S04. An electrode substrate is provided, and the electrode substrate is integrally formed with the epitaxial stack on the surface of the epitaxial stack by a bonding process;

[0036] S05. Peel off the growth substrate to expose the first type of semiconductor layer;

[0037] S06. A first electrode is formed on the exposed surface of the first type of semiconductor layer;

[0038] S07. Repeat steps S01 to S06 to obtain wafers with red LED chips, green LED chips and blue LED chips respectively.

[0039] S08. The electrodes of the wafer having red LED chips, green LED chips and blue LED chips are bonded together by an insulating material layer to form a whole.

[0040] S09. Through a cutting process, several light-emitting units with red, green, and blue primary colors are formed; wherein, the electrode substrate serves as the second electrode of the vertical structure LED chip;

[0041] S10. A substrate is provided, the substrate having a plurality of spaced-apart electrode connection components;

[0042] S11. The light-emitting unit is laid horizontally on the surface of the substrate, and the bipolar electrodes of the red LED chip, green LED chip and blue LED chip are respectively connected to the electrode connection component.

[0043] Preferably, the surface of the vertical LED chip facing away from the substrate is the light-emitting surface; and a reflector is provided on the non-light-emitting surface of the LED chip.

[0044] As can be seen from the above technical solution, the micro light-emitting element provided by the present invention includes a substrate and a plurality of LED chips located on the surface of the substrate; wherein, the substrate has a plurality of spaced-apart electrode connection components; the LED chips include vertical structure LED chips; the vertical structure LED chips lie horizontally on the surface of the substrate, and the two polar electrodes of the vertical structure LED chips are respectively connected to the electrode connection components. Through the vertical structure LED chips, the micro light-emitting element has the advantages of high luminous efficiency, good heat dissipation, high reliability, and maximized light-emitting area; at the same time, it can overcome the size limitations of existing chip technology, making the LED light-emitting unit smaller.

[0045] Furthermore, the surface of the vertical structure LED chip facing away from the substrate is the light-emitting surface, and a reflector is provided on the non-light-emitting surface of the LED chip; thereby achieving a Lambertian distribution of the light-emitting morphology of the LED chip, giving the LED chip a good light-emitting morphology.

[0046] Secondly, the vertically structured LED chip includes red, green, and blue LED chips; and these chips are arranged side-by-side on the substrate surface to form a light-emitting unit with red, green, and blue primary colors. Furthermore, adjacent LED chips are bonded together using an insulating bonding material. Based on this structure, while achieving the display effect of Mini-LED or Micro-LED chips, light-emitting units can be formed by bonding the LEDs at the wafer end, realizing the integration of multiple LED chips and full-color processing, avoiding the multiple mass transfers required in traditional light mixing processes.

[0047] The present invention also provides a method for fabricating a micro-element structure in which two adjacent LED chips are spaced apart from each other. While achieving the above-mentioned technical effects, it is simple to operate and easy to implement.

[0048] The present invention also provides another method for fabricating a micro-element structure, wherein two adjacent LED chips are integrated by means of an insulating bonding material, and a light-emitting unit can be formed by bonding at the wafer end of the LED, thus avoiding the complicated mass transfer process; while achieving the above technical effects, it is simple to operate and easy to implement. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0050] Figure 1 The light-emitting morphology of micro LED chips in the prior art;

[0051] Figure 2 This is a schematic diagram of the structure of the micro light-emitting element provided in Embodiment 1 of the present invention;

[0052] Figures 3.1 to 3.10 This is a schematic diagram of the structure corresponding to the method for fabricating the micro light-emitting element provided in Embodiment 1 of the present invention;

[0053] Figure 4 This is a schematic diagram of the structure of the micro light-emitting element provided in Embodiment 2 of the present invention;

[0054] Figures 5.1 to 5.12 This is a schematic diagram of the structure corresponding to the method for fabricating the micro light-emitting element provided in Embodiment 2 of the present invention;

[0055] Explanation of symbols in the diagram:

[0056] 1. Growth substrate; 2. Type I semiconductor layer; 3. Active region; 4. Type II semiconductor layer; 5. Mirror; 6. Electrode substrate; 7. First electrode; 8. Insulating material layer; 10. Channel; 11. Substrate; 12. Electrode connection component; L1, L2, L3...Ln: LED chip. Detailed Implementation

[0057] To make the content of this invention clearer, the following description, in conjunction with the accompanying drawings, further illustrates the invention. This invention is not limited to this specific embodiment. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0058] Example 1

[0059] like Figure 2 As shown, a micro light-emitting element includes a substrate 11 and a plurality of LED chips (L1, L2, L3...Ln) located on the surface of the substrate 11; wherein, the substrate 11 has a plurality of spaced electrode connection components 12; the LED chips include vertical structure LED chips; the vertical structure LED chips lie horizontally on the surface of the substrate 11, and the two polar electrodes of the vertical structure LED chips are respectively connected to the electrode connection components 12.

[0060] It should be emphasized that, in order to highlight the technical inventive points of the present invention, Figure 3 only illustrates 6 LED chips in the micro-light-emitting device. In actual use, the surface of the substrate 11 contains tens of thousands of LED chips, depending on the specific situation. This application does not limit this.

[0061] Based on the above embodiments, in one embodiment of this application, the surface of the vertical structure LED chip facing away from the substrate 11 is the light-emitting surface, and a reflector 5 is provided on the non-light-emitting surface of the LED chip.

[0062] Based on the above embodiments, in one embodiment of this application, the reflector 5 includes at least one of a DBR structure, an ODR structure, and a metal reflector.

[0063] Based on the above embodiments, in one embodiment of this application, when the reflector 5 is made of a conductive material, a passivation layer is also provided on the non-light-emitting surface of the LED chip to prevent the LED chip from short-circuiting.

[0064] Based on the above embodiments, in one embodiment of this application, the passivation layer includes SiO2, SiC, AlN, SiONx, and SiN. x One or more of them.

[0065] Based on the above embodiments, in one embodiment of this application, each of the electrode connection components 12 is arranged side by side on the surface of the substrate 11.

[0066] Based on the above embodiments, in one embodiment of this application, the vertical structure LED chip includes a red LED chip, a green LED chip, and a blue LED chip (L1, L2, and L3, respectively); and the red LED chip, green LED chip, and blue LED chip are arranged side by side on the surface of the substrate 11 to form a light-emitting unit with red, green, and blue primary colors.

[0067] Based on the above embodiments, in one embodiment of this application, two adjacent LED chips are spaced apart from each other.

[0068] Based on the above embodiments, in one embodiment of this application, the micro light-emitting element includes a Mini-LED chip or a Micro-LED chip.

[0069] Based on the above embodiments, in one embodiment of this application, the vertical structure LED chip includes a second type semiconductor layer 4, an active region 3, a first type semiconductor layer 2, and a first electrode 7, which are sequentially stacked on the surface of the electrode substrate 6.

[0070] The semiconductor layer 4 (type II), active region 3, and semiconductor layer 2 (type I) are semiconductor barrier stacks obtained through MOCVD or other growth methods. These semiconductor barrier stacks are semiconductor materials capable of providing conventional radiation such as ultraviolet, blue, green, yellow, red, and infrared light. Specifically, they can be materials in the 200–950 nm range, such as common nitrides, specifically gallium nitride-based semiconductor barrier stacks. Gallium nitride-based barrier stacks are commonly doped with elements such as aluminum and indium, primarily providing radiation in the 200–550 nm wavelength range; or common aluminum gallium indium phosphide-based or aluminum gallium arsenide-based semiconductor barrier stacks, primarily providing radiation in the 550–950 nm wavelength range. The semiconductor barrier stack mainly includes semiconductor layer 4 (type II), active region 3, and semiconductor layer 2 (type I). Semiconductor layer 2 (type I) and semiconductor layer 4 (type II) can be doped with n-type or p-type doping, respectively, to achieve material layers that provide at least electrons or holes. The n-type semiconductor layer can be doped with n-type dopants such as Si, Ge, or Sn, while the p-type doped semiconductor layer can be doped with p-type dopants such as Mg, Zn, Ca, Sr, or Ba. The second-type semiconductor layer 4, the active region 3, and the first-type semiconductor layer 2 can be formed from 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 second-type semiconductor layer 4 and the first-type semiconductor layer 2 include a capping layer that provides electrons or holes, and may include other layer materials such as a current spreading layer, a window layer, or an ohmic contact layer, configured as different multilayers depending on the doping concentration or composition content. The active region 3 is the region that provides light radiation by facilitating electron-hole recombination. Different materials can be selected according to different emission wavelengths. The active region 3 can be a periodic structure of a single quantum well or multiple quantum wells. By adjusting the composition ratio of the semiconductor materials in the active region 3, it is desired to radiate light of different wavelengths.

[0071] The first electrode 7 and the second electrode are respectively disposed on the front and back sides of the LED chip, and the first electrode 7 and the second electrode are preferably metal materials that form good ohmic contact with the semiconductor epitaxial material.

[0072] This embodiment also provides another method for fabricating a micro light-emitting element, the method comprising the following steps:

[0073] S01, such as Figure 3.1 As shown, a growth substrate 1 is provided;

[0074] It should be noted that the type of growth substrate 1 is not limited in the micro light-emitting element of this embodiment. For example, the substrate can be, but is not limited to, sapphire substrate, silicon substrate, GaAs substrate, etc.

[0075] S02, such as Figure 3.2As shown, an epitaxial stack is grown on the surface of the growth substrate 1. The epitaxial stack includes a first type semiconductor layer 2, an active region 3, and a second type semiconductor layer 4 grown sequentially.

[0076] The semiconductor layer 4 (type II), active region 3, and semiconductor layer 2 (type I) are semiconductor barrier stacks obtained through MOCVD or other growth methods. These semiconductor barrier stacks are semiconductor materials capable of providing conventional radiation such as ultraviolet, blue, green, yellow, red, and infrared light. Specifically, they can be materials in the 200–950 nm range, such as common nitrides, specifically gallium nitride-based semiconductor barrier stacks. Gallium nitride-based barrier stacks are commonly doped with elements such as aluminum and indium, primarily providing radiation in the 200–550 nm wavelength range; or common aluminum gallium indium phosphide-based or aluminum gallium arsenide-based semiconductor barrier stacks, primarily providing radiation in the 550–950 nm wavelength range. The semiconductor barrier stack mainly includes semiconductor layer 4 (type II), active region 3, and semiconductor layer 2 (type I). Semiconductor layer 2 (type I) and semiconductor layer 4 (type II) can be doped with n-type or p-type doping, respectively, to achieve material layers that provide at least electrons or holes. The n-type semiconductor layer can be doped with n-type dopants such as Si, Ge, or Sn, while the p-type doped semiconductor layer can be doped with p-type dopants such as Mg, Zn, Ca, Sr, or Ba. The second-type semiconductor layer 4, the active region 3, and the first-type semiconductor layer 2 can be formed from 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 second-type semiconductor layer 4 and the first-type semiconductor layer 2 include a capping layer that provides electrons or holes, and may include other layer materials such as a current spreading layer, a window layer, or an ohmic contact layer, configured as different multilayers depending on the doping concentration or composition content. The active region 3 is the region that provides light radiation by facilitating electron-hole recombination. Different materials can be selected according to different emission wavelengths. The active region 3 can be a periodic structure of a single quantum well or multiple quantum wells. By adjusting the composition ratio of the semiconductor materials in the active region 3, it is desired to radiate light of different wavelengths.

[0077] S03, such as Figure 3.3 As shown, the epitaxial stack surface is etched to the surface of the growth substrate 1 to form a plurality of epitaxial units arranged at intervals through the channel 10.

[0078] In one embodiment of this application, the epitaxial stack is deeply etched to the surface of the exposed growth substrate 1 to form a plurality of epitaxial units arranged at intervals through channels 10; this includes using an inductively coupled plasma (ICP) process, with etching gases including Cl2, Ar, and O2. However, this application does not limit this, and the specific method depends on the circumstances.

[0079] It should be emphasized that, in order to highlight the technical inventive points of this invention, only two epitaxial units arranged at intervals through the channel 10 are shown in the figure in this step; in actual use, the surface of the growth substrate 1 contains tens of thousands of epitaxial units, depending on the specific situation, and this application does not limit this.

[0080] S04, such as Figure 3.4 As shown, one side of the epitaxial unit is defined as the light-emitting surface, and a reflector 5 is made on the side that is not the light-emitting surface.

[0081] S05, such as Figure 3.5 As shown, an electrode substrate 6 is provided, and the electrode substrate 6 is integrally formed with the epitaxial stack on the surface of the epitaxial stack by a bonding process;

[0082] S06, such as Figure 3.6 As shown, the growth substrate 1 is peeled off to expose the first type semiconductor layer 2;

[0083] S07, such as Figure 3.7 As shown, a first electrode 7 is formed on the exposed surface of the first type semiconductor layer 2;

[0084] S08, such as Figure 3.8 As shown, several independent vertical structure LED chips are formed by cutting, wherein the electrode substrate 6 serves as the second electrode of the vertical structure LED chip;

[0085] S09, such as Figure 3.9 As shown, a substrate 11 is provided, the substrate 11 having a plurality of spaced-apart electrode connection components 12;

[0086] S10, such as Figure 3.10 As shown, the vertical structure LED chip is laid horizontally on the surface of the substrate 11, and the two polar electrodes of the vertical structure LED chip are respectively connected to the electrode connection component 12.

[0087] S11. Repeat step S10 to make the substrate 11 have a plurality of vertical structure LED chips, with adjacent vertical structure LED chips spaced apart from each other.

[0088] Based on the above embodiments, in one embodiment of this application, red LED chips, green LED chips, and blue LED chips are obtained respectively through the preparation method; and, the red LED chips, green LED chips, and blue LED chips (such as...) Figure 1 The L1, L2, and L3 shown are arranged side by side on the surface of the substrate 11 to form light-emitting units with red, green, and blue primary colors.

[0089] As can be seen from the above technical solution, the micro light-emitting element provided by the present invention includes a substrate 11 and a plurality of LED chips located on the surface of the substrate 11; wherein, the substrate 11 has a plurality of spaced-apart electrode connection components 12; the LED chips include vertical structure LED chips; the vertical structure LED chips lie horizontally on the surface of the substrate 11, and the two polar electrodes of the vertical structure LED chips are respectively connected to the electrode connection components 12. Through the vertical structure LED chips, the micro light-emitting element has the advantages of high luminous efficiency, good heat dissipation, high reliability, and maximized light-emitting area; at the same time, it can overcome the size limitations of existing chip technology, making the LED light-emitting unit smaller.

[0090] Furthermore, the surface of the vertical structure LED chip facing away from the substrate 11 is the light-emitting surface, and a reflector 5 is provided on the non-light-emitting surface of the LED chip; thereby realizing that the light-emitting morphology of the LED chip is Lambertian, so that the LED chip has a good light-emitting morphology.

[0091] Secondly, the vertically structured LED chip includes red, green, and blue LED chips; and these chips are arranged side-by-side on the surface of the substrate 11 to form a light-emitting unit with red, green, and blue primary colors. This achieves the display effect of a Mini-LED or Micro-LED chip.

[0092] The present invention also provides a method for fabricating a micro-element structure in which two adjacent LED chips are spaced apart from each other. While achieving the above-mentioned technical effects, it is simple to operate and easy to implement.

[0093] Example 2

[0094] like Figure 4 As shown, the only difference between this embodiment and embodiment 1 is that in the micro light-emitting element provided in this embodiment, two adjacent LED chips are integrated by an insulating material layer 8.

[0095] This invention also provides a method for fabricating the micro light-emitting element, the method comprising the following steps:

[0096] S01, such as Figure 5.1 As shown, a growth substrate 1 is provided;

[0097] It should be noted that the type of growth substrate 1 is not limited in the micro light-emitting element of this embodiment. For example, the substrate can be, but is not limited to, sapphire substrate, silicon substrate, GaAs substrate, etc.

[0098] S02, such as Figure 5.2As shown, an epitaxial stack is grown on the surface of the growth substrate 1. The epitaxial stack includes a first type semiconductor layer 2, an active region 3, and a second type semiconductor layer 4 grown sequentially.

[0099] The semiconductor layer 4 (type II), active region 3, and semiconductor layer 2 (type I) are semiconductor barrier stacks obtained through MOCVD or other growth methods. These semiconductor barrier stacks are semiconductor materials capable of providing conventional radiation such as ultraviolet, blue, green, yellow, red, and infrared light. Specifically, they can be materials in the 200–950 nm range, such as common nitrides, specifically gallium nitride-based semiconductor barrier stacks. Gallium nitride-based barrier stacks are commonly doped with elements such as aluminum and indium, primarily providing radiation in the 200–550 nm wavelength range; or common aluminum gallium indium phosphide-based or aluminum gallium arsenide-based semiconductor barrier stacks, primarily providing radiation in the 550–950 nm wavelength range. The semiconductor barrier stack mainly includes semiconductor layer 4 (type II), active region 3, and semiconductor layer 2 (type I). Semiconductor layer 2 (type I) and semiconductor layer 4 (type II) can be doped with n-type or p-type doping, respectively, to achieve material layers that provide at least electrons or holes. The n-type semiconductor layer can be doped with n-type dopants such as Si, Ge, or Sn, while the p-type doped semiconductor layer can be doped with p-type dopants such as Mg, Zn, Ca, Sr, or Ba. The second-type semiconductor layer 4, the active region 3, and the first-type semiconductor layer 2 can be formed from 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 second-type semiconductor layer 4 and the first-type semiconductor layer 2 include a capping layer that provides electrons or holes, and may include other layer materials such as a current spreading layer, a window layer, or an ohmic contact layer, configured as different multilayers depending on the doping concentration or composition content. The active region 3 is the region that provides light radiation by facilitating electron-hole recombination. Different materials can be selected according to different emission wavelengths. The active region 3 can be a periodic structure of a single quantum well or multiple quantum wells. By adjusting the composition ratio of the semiconductor materials in the active region 3, it is desired to radiate light of different wavelengths.

[0100] S03, such as Figure 5.3 As shown, the epitaxial stack surface is etched to the surface of the growth substrate 1 to form a plurality of epitaxial units arranged at intervals through the channel 10.

[0101] In one embodiment of this application, the epitaxial stack is deeply etched to the surface of the exposed growth substrate 1 to form a plurality of epitaxial units arranged at intervals through channels 10; this includes using an inductively coupled plasma (ICP) process, with etching gases including Cl2, Ar, and O2. However, this application does not limit this, and the specific method depends on the circumstances.

[0102] It should be emphasized that, in order to highlight the technical inventive points of this invention, only two epitaxial units arranged at intervals through the channel 10 are shown in the figure in this step; in actual use, the surface of the growth substrate 1 contains tens of thousands of epitaxial units, depending on the specific situation, and this application does not limit this.

[0103] S04, such as Figure 5.4 As shown, one side of the epitaxial unit is defined as the light-emitting surface, and a reflector 5 is made on the side that is not the light-emitting surface.

[0104] S05, such as Figure 5.5 As shown, an electrode substrate 6 is provided, and the electrode substrate 6 is integrally formed with the epitaxial stack on the surface of the epitaxial stack by a bonding process;

[0105] S06, such as Figure 5.6 As shown, the growth substrate 1 is peeled off to expose the first type semiconductor layer 2;

[0106] S07, such as Figure 5.7 As shown, a first electrode 7 is formed on the exposed surface of the first type semiconductor layer 2;

[0107] S08. Repeat steps S01 to S07 to obtain wafers with red LED chips, green LED chips, and blue LED chips respectively. Figure 5.8 As shown,;

[0108] It should be emphasized that the LED chip with the desired wavelength is achieved by combining the growth substrate 1 with the epitaxial stack.

[0109] The semiconductor layer 4 (type II), active region 3, and semiconductor layer 2 (type I) are semiconductor barrier stacks obtained through MOCVD or other growth methods. These semiconductor barrier stacks are semiconductor materials capable of providing conventional radiation such as ultraviolet, blue, green, yellow, red, and infrared light. Specifically, they can be materials in the 200–950 nm range, such as common nitrides, specifically gallium nitride-based semiconductor barrier stacks. Gallium nitride-based barrier stacks are commonly doped with elements such as aluminum and indium, primarily providing radiation in the 200–550 nm wavelength range; or common aluminum gallium indium phosphide-based or aluminum gallium arsenide-based semiconductor barrier stacks, primarily providing radiation in the 550–950 nm wavelength range. The semiconductor barrier stack mainly includes semiconductor layer 4 (type II), active region 3, and semiconductor layer 2 (type I). Semiconductor layer 2 (type I) and semiconductor layer 4 (type II) can be doped with n-type or p-type doping, respectively, to achieve material layers that provide at least electrons or holes. The n-type semiconductor layer can be doped with n-type dopants such as Si, Ge, or Sn, while the p-type doped semiconductor layer can be doped with p-type dopants such as Mg, Zn, Ca, Sr, or Ba. The second-type semiconductor layer 4, the active region 3, and the first-type semiconductor layer 2 can be formed from 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 second-type semiconductor layer 4 and the first-type semiconductor layer 2 include a capping layer that provides electrons or holes, and may include other layer materials such as a current spreading layer, a window layer, or an ohmic contact layer, configured as different multilayers depending on the doping concentration or composition content. The active region 3 is the region that provides light radiation by facilitating electron-hole recombination. Different materials can be selected according to different emission wavelengths. The active region 3 can be a periodic structure of a single quantum well or multiple quantum wells. By adjusting the composition ratio of the semiconductor materials in the active region 3, it is desired to radiate light of different wavelengths.

[0110] S09, such as Figure 5.9 As shown, the electrodes of the wafer having red LED chips, green LED chips and blue LED chips are bonded together through an insulating material layer 8 to form a single unit;

[0111] In this embodiment, the insulating material layer 8 includes, but is not limited to, silicon dioxide, silicon nitride, and silicon oxynitride.

[0112] S10, such as Figure 5.10 As shown, through a cutting process, several light-emitting units with red, green, and blue primary colors are formed, wherein the electrode substrate serves as the second electrode of the vertical structure LED chip;

[0113] S11, such as Figure 5.11 As shown, a substrate 11 is provided, the substrate 11 having a plurality of spaced-apart electrode connection components 12;

[0114] S12, such as Figure 5.12As shown, the light-emitting unit is laid horizontally on the surface of the substrate 11, and the bipolar electrodes of the red LED chip, green LED chip and blue LED chip are respectively connected to the electrode connection component 12.

[0115] As can be seen from the above technical solution, the micro light-emitting element provided by the present invention includes a substrate 11 and a plurality of LED chips located on the surface of the substrate 11; wherein, the substrate 11 has a plurality of spaced-apart electrode connection components 12; the LED chips include vertical structure LED chips; the vertical structure LED chips lie horizontally on the surface of the substrate 11, and the two polar electrodes of the vertical structure LED chips are respectively connected to the electrode connection components 12. Through the vertical structure LED chips, the micro light-emitting element has the advantages of high luminous efficiency, good heat dissipation, high reliability, and maximized light-emitting area; at the same time, it can overcome the size limitations of existing chip technology, making the LED light-emitting unit smaller.

[0116] Furthermore, the surface of the vertical structure LED chip facing away from the substrate 11 is the light-emitting surface, and a reflector 5 is provided on the non-light-emitting surface of the LED chip; thereby realizing that the light-emitting morphology of the LED chip is Lambertian, giving the LED chip a good light-emitting morphology.

[0117] Secondly, the vertically structured LED chip includes red, green, and blue LED chips; and these chips are arranged side-by-side on the surface of the substrate 11 to form a light-emitting unit with red, green, and blue primary colors. Furthermore, adjacent LED chips are bonded together using an insulating bonding material. Based on this structure, while achieving the display effect of Mini-LED or Micro-LED chips, light-emitting units can be formed by bonding the LEDs at the wafer end, realizing the integration of multiple LED chips and full-color processing, avoiding the multiple mass transfers required in traditional light mixing processes.

[0118] The present invention also provides a method for fabricating a micro-element structure, wherein two adjacent LED chips are integrated by means of an insulating bonding material, and a light-emitting unit can be formed by bonding at the wafer end of the LED, thus avoiding the complicated mass transfer process; while achieving the above-mentioned technical effects, it is simple to operate and easy to implement.

[0119] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0120] It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0121] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A miniature light-emitting element, characterized in that, The device includes a substrate and a plurality of LED chips located on the surface of the substrate; wherein the substrate has a plurality of spaced-apart electrode connection components; the LED chips include vertical structure LED chips; the vertical structure LED chips lie horizontally on the surface of the substrate, and the two polar electrodes of the vertical structure LED chips are respectively connected to the electrode connection components; The vertical LED chip has a light-emitting surface on the side facing away from the substrate, and a reflector is provided on the non-light-emitting surface of the LED chip. Each of the electrode connection components is arranged side by side on the surface of the substrate.

2. The micro light-emitting element according to claim 1, characterized in that, The reflector includes a DBR structure and an ODR structure.

3. The micro light-emitting element according to claim 1, characterized in that, The vertical structure LED chip includes a red LED chip, a green LED chip, and a blue LED chip; and the red LED chip, green LED chip, and blue LED chip are arranged side by side on the surface of the substrate to form a light-emitting unit with red, green, and blue primary colors.

4. The micro light-emitting element according to any one of claims 1 to 3, characterized in that, Adjacent LED chips are spaced apart from each other.

5. The micro light-emitting element according to any one of claims 1 to 3, characterized in that, Adjacent LED chips are bonded together as one unit through an insulating material layer.

6. The micro light-emitting element according to any one of claims 1 to 3, characterized in that, The micro-light-emitting element includes a Mini-LED chip or a Micro-LED chip.

7. The micro light-emitting element according to claim 1, characterized in that, The vertical structure LED chip includes a second type semiconductor layer, an active region, a first type semiconductor layer, and a first electrode, which are sequentially stacked on the surface of an electrode substrate.

8. A method for fabricating a micro light-emitting element, characterized in that, The preparation method includes the following steps: S01, Provide a growth substrate; S02. An epitaxial stack is grown on the surface of the growth substrate, the epitaxial stack comprising a first type semiconductor layer, an active region and a second type semiconductor layer grown sequentially. S03. Etch along the surface of the epitaxial stack to the surface of the growth substrate to form a plurality of epitaxial units arranged at intervals between each other through channels; S04. An electrode substrate is provided, and the electrode substrate is integrally formed with the epitaxial stack on the surface of the epitaxial stack by a bonding process; S05. Peel off the growth substrate to expose the first type of semiconductor layer; S06. A first electrode is formed on the exposed surface of the first type of semiconductor layer; S07. A plurality of vertical structure LED chips are formed by cutting, wherein the electrode substrate serves as the second electrode of the vertical structure LED chip; S08. A substrate is provided, the substrate having a plurality of spaced-apart electrode connection components; S09. The vertical structure LED chip is laid horizontally on the surface of the substrate, and the two polar electrodes of the vertical structure LED chip are respectively connected to the electrode connection component. S10. Repeat step S09 to make the substrate have a plurality of vertical structure LED chips, with adjacent vertical structure LED chips spaced apart from each other. The surface of the vertical LED chip facing away from the substrate is the light-emitting surface; and a reflector is provided on the non-light-emitting surface of the LED chip. Each of the electrode connection components is arranged side by side on the surface of the substrate.

9. The method for fabricating a micro light-emitting element according to claim 8, characterized in that, Red LED chips, green LED chips, and blue LED chips are obtained sequentially through the preparation method; and the red LED chips, green LED chips, and blue LED chips are arranged side by side on the surface of the substrate to form a light-emitting unit with red, green, and blue primary colors.

10. A method for fabricating a micro light-emitting element, characterized in that, The preparation method includes the following steps: S01, Provide a growth substrate; S02. An epitaxial stack is grown on the surface of the growth substrate, the epitaxial stack comprising a first type semiconductor layer, an active region and a second type semiconductor layer grown sequentially. S03. Etch along the surface of the epitaxial stack to the surface of the growth substrate to form a plurality of epitaxial units arranged at intervals between each other through channels; S04. An electrode substrate is provided, and the electrode substrate is integrally formed with the epitaxial stack on the surface of the epitaxial stack by a bonding process; S05. Peel off the growth substrate to expose the first type of semiconductor layer; S06. A first electrode is formed on the exposed surface of the first type of semiconductor layer; S07. Repeat steps S01 to S06 to obtain wafers with red LED chips, green LED chips and blue LED chips respectively. S08. The electrodes of the wafer having red LED chips, green LED chips and blue LED chips are bonded together by an insulating material layer to form a whole. S09. Through a cutting process, several light-emitting units with red, green and blue primary colors are formed, wherein the electrode substrate serves as the second electrode of the vertical structure LED chip; S10. A substrate is provided, the substrate having a plurality of spaced-apart electrode connection components; S11. The light-emitting unit is laid horizontally on the surface of the substrate, and the bipolar electrodes of the red LED chip, green LED chip and blue LED chip are respectively connected to the electrode connection components. The surface of the vertical LED chip facing away from the substrate is the light-emitting surface; and a reflector is provided on the non-light-emitting surface of the LED chip. Each of the electrode connection components is arranged side by side on the surface of the substrate.

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