Micro-LED Chip, Method for Manufacturing the Same, and Applications

Abstract

This application discloses a Micro-LED chip, a manufacturing method thereof, and applications. The Micro-LED chip includes an LED chip structure and a first metasurface conductive structure layer. The first metasurface conductive structure layer includes a first conductive layer electrically bonded on the light-emitting surface of the LED chip structure, and a metasurface structure laminated and / or integrally provided on the first conductive layer. The metasurface structure is used to modulate at least the emission angle or wavelength of the light emitted from the light-emitting surface. Based on the technical solution of this application, full-color of the Micro-LED chip can be realized, the light emission rate and collimation can be increased, and by adopting a large-scale standard semiconductor process, the manufacturing of the Micro-LED chip and the integration of the Micro-LED pixel and the display unit can be realized, improving the production efficiency and yield rate of the Micro-LED chip and reducing costs.

Description

Technical Field

[0001] (Related Application) This application claims priority based on the Chinese patent application with application number 2023105800924 and application title "Micro-LED Chip and Its Manufacturing Method and Applications", filed on May 22, 2023.

[0002] (Technical Field) This application relates to semiconductor optoelectronic devices, specifically, to Micro-LED chips and their manufacturing methods and applications, and belongs to the technical field of semiconductor optoelectronics.

Background Art

[0003] Micro-LED (Micro-Light Emitting Diode) has excellent performance such as brightness, contrast, luminous efficiency, resolution, response speed, energy consumption, shock resistance, operating temperature, and service life. It is an indispensable technology in the new-generation display field and has broad prospects in fields such as ultra-high-definition large-screen displays, micro-displays, flexible displays, head-mounted displays, AR (augmented reality), and VR (virtual reality). In the application of current display technologies, LED-based display technologies occupy an important position in people's lives. Among them, the new gallium nitride (GaN) Micro-LED display technology is one of the most promising display technologies and may gradually replace other display technologies and become the ultimate mainstream technology in the display field.

[0004] The light-emitting characteristics of the GaN LED active region are isotropic, emitting light in all directions with a large light dispersion angle. Therefore, the substantial emission of light into the light-emitting window is very small, which seriously affects the effective luminous efficiency of the LED. In the most common display field, a larger viewing angle, light chroma, and contrast are required. In the fields of industrial exposure and image projection restricted by the aperture ratio of the projection lens, Micro-LED devices and their arrays need to emit light with a smaller dispersion angle, higher light extraction efficiency, and high luminous quality.

[0005] Currently, in order to improve the light extraction efficiency and light emission direction of Micro-LEDs, resonator structures, lens systems, etc. are mainly used. Among them, the resonator structure creates two reflection structures at the bottom and top of the Micro-LED active region. Through the formation of a microcavity structure, the emitted light from the active region is reflected back and forth under the action of the resonator, realizing constructive interference in phase, improving the emission efficiency and collimation of the light emitted from the active region, and achieving the improvement of the optical characteristics of the device. However, this method has a complex process, and the manufacturing process at the bottom is difficult. It is only suitable for the Micro-LED device structure with a peeling structure by removing the Micro-LED material from the original substrate and increasing the bottom reflection layer. The lens system mainly changes the light-emitting optical path through specific microlenses to achieve enhanced light-emitting collimation of the device. However, its manufacturing is difficult. Generally, complex photolithography, etching, and other processes are required to add a lens system to the top of the Micro-LED. Furthermore, the volume of the lens system is large, which is not suitable for lightweight applications and is also costly.

[0006] In the application of Micro-LED color displays to other parties, it is usually necessary to convert the monochromatic wavelength Micro-LED. Currently, as a general solution, there are mainly macro transfer and color conversion of quantum dot films. Among them, for the macro transfer technology, mechanical transfer or other methods are required to arrange Micro-LED units of different colors on the same substrate. Due to the very high pixel density, the transfer amount is very large, and generally special large devices are required. In the adsorption of the transfer process, the control accuracy requirement for arranging Micor-LED pixels is very high, and the adsorption success rate of the transfer process directly affects the product yield. In addition, the pixel pitch after transfer and arrangement is large, which is not suitable for high-resolution display applications. The quantum dot color conversion technology generally uses quantum dot films such as zinc sulfide, cadmium selenide, and chalcogenide to convert the blue light emitted from conventional GaN Micro-LEDs into green light and red light to achieve color conversion. However, the existing quantum dot technology is not fully mature, and it is difficult to control the uniformity of the scale of quantum dots, and the deterioration of the scale affects the color purity. At the same time, since the existing quantum dots are generally difficult to withstand high temperatures, sufficient heat treatment of the Micro-LED chip is required, and other problems such as the mutual interference between quantum dots of different colors need to be further solved to ensure the color uniformity in the spray process. Furthermore, since quantum dots are produced by chemical methods, they are not environmentally friendly.

Summary of the Invention

Problems to be Solved by the Invention

[0007] The main object of this application is to provide a Micro-LED chip, its manufacturing method, and applications to overcome the drawbacks of the prior art.

Means for Solving the Problems

[0008] To achieve the object of the above application, this application adopts the following technical solutions.

[0009] One aspect of the present application provides a Micro-LED chip including an LED chip structure and a first metasurface conductive structure layer, and the first metasurface conductive structure layer is a first conductive layer electrically bonded on the light-emitting surface of the LED chip structure, and a metasurface structure laminated and / or integrally provided on the first conductive layer and used for modulating at least the emission angle and / or wavelength of the light emitted from the light-emitting surface.

[0010] Another aspect of the present application provides a method for manufacturing the Micro-LED chip, and this method includes manufacturing an LED chip structure, providing a first conductive layer and a metasurface structure on the light-emitting surface of the LED chip structure, and the metasurface structure is laminated and / or integrally provided on the first conductive layer.

[0011] Yet another aspect of the present application provides the use of the Micro-LED chip in the manufacture of optoelectronic devices, and the optoelectronic devices include, but are not limited to, display devices, microdisplay devices, etc.

[0012] Compared with the prior art, the present application can not only fully exert the excellent performance of GaN-based Micro-LEDs by integrating a metasurface structure into the Micro-LED chip, but also realize full-color Micro-LEDs simply and at low cost, greatly improving its light emission rate and collimation. At the same time, the manufacture of Micro-LED chips and the integration of Micro-LED pixels and display units can be realized by large-scale standard semiconductor process processes, effectively improving the production efficiency and yield rate of Micro-LED chips, greatly reducing its cost, and contributing to the development and application of the Micro-LED display field.

Brief Description of the Drawings

[0013] The attached drawings of the specification constituting a part of this application are used to provide a further understanding of this application. The exemplary embodiments of this application and their descriptions are used for the interpretation of this application and do not constitute an undue limitation of this application.

[0014]

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Embodiments for Carrying Out the Invention

[0015] This application integrates a metasurface structure into a Micro-LED chip, particularly provides a conductive metasurface structure on the light-emitting surface of the Micro-LED chip, optimizes its light-emitting angle, contributes to the improvement of its light extraction efficiency, and the reduction of the difficulty and cost of the colorization process. Hereinafter, the technical solutions of this application will be described in more detail.

[0016] In this specification, the metasurface structure is a two-dimensional planar pattern formed by arranging materials with special electromagnetic properties according to a certain arrangement. It mainly consists of sub-wavelength nano-sized microstructure units and can realize flexible adjustment of the amplitude, phase, polarization, etc. of incident light.

[0017] The Micro-LED chips provided by some embodiments of the present application include an LED chip structure and a first metasurface conductive structure layer. The first metasurface conductive structure layer A first conductive layer electrically bonded on the light-emitting surface of the LED chip structure, Stacked on and / or integrally provided with the first conductive layer, modulating at least the emission angle and / or wavelength of the light emitted from the light-emitting surface, and achieving at least one or more of the effects of optimizing the collimation of the emitted light of the Micro-LED chip, improving the light extraction efficiency of the Micro-LED chip, and changing the color of the light emitted by the Micro-LED chip. It includes a metasurface structure.

[0018] In one embodiment, the metasurface structure includes a first metasurface structure. The first conductive layer includes a plurality of first pattern structures. The plurality of first pattern structures are distributed along a direction parallel to the light-emitting surface to form the first metasurface structure. Here, the first conductive layer includes a metal conductive layer or a non-metal conductive layer.

[0019] Furthermore, the thickness of the metal conductive layer can be 20 nm or less. It has the first metasurface structure, which enables the metal conductive layer to have better light transmissibility and fully exerts the performance of modulating the emission angle and / or wavelength of light. At the same time, an array electrode can be formed. For example, in order to have good light transmission performance, the thickness of the metal conductive layer can be 0.1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 nm or less.

[0020] Furthermore, the thickness of the metal conductive layer may exceed 20 nm, having the first metasurface structure, enabling the metal conductive layer to have better current spreading ability, while maintaining good light transmittance by utilizing the first metasurface structure, and at the same time enabling the first metasurface structure to fully exert its performance of modulating the light emission angle and / or wavelength, improving at least one of the light emission efficiency, collimation and full color of the Micro-LED chip, and an array electrode can also be formed, each array electrode corresponding to the corresponding light-emitting pixel point, facilitating precise adjustment of the photoelectric field of each pixel unit.

[0021] In particular, when the first conductive layer is a metal layer and the first pattern structure has nanoscale dimensions, it also exhibits a strong photoelectric field local surface plasmon resonance effect as a metal nanostructure. So when the light emitted from the LED chip structure is incident on the first conductive layer and the frequency of the light coincides with the vibration frequency of the conductive electrons of the metal nanostructure, the first pattern structure has a strong absorption effect on the photon energy and shows a strong resonance absorption peak on the spectrum. Furthermore, while a plurality of the first pattern structures form the first metasurface structure, the metal nanostructures have a plasma excitation resonance effect, and since these metal nanostructures are arranged more compactly, mutual coupling occurs between the nanostructures, making the overall resonance intensity stronger, and ultimately increasing the color rendering efficiency of the Micro-LED chip.

[0022] In one embodiment, the first conductive layer includes a metal conductive layer or a non-metal conductive layer, the thickness of the metal conductive layer is 20 nm or less, and it extends continuously along the direction parallel to the light emission surface.

[0023] Furthermore, the material of the metal conductive layer includes, but is not limited to, any one or a combination of indium, tin, silver, platinum, gold, titanium, aluminum, nickel, chromium, molybdenum and copper.

[0024] In one embodiment, the material of the non-metallic conductive layer includes, but is not limited to, ITO (indium tin oxide) or other transparent conductive materials, such as graphene, carbon nanotubes, conductive polymers, etc. or combinations thereof.

[0025] In one embodiment, the thickness of the non-metallic conductive layer is 1 nm to 500 nm.

[0026] Furthermore, in a direction parallel to the light-emitting surface, the dimension of the first pattern structure is 0.1 nm to 1 μm, preferably 80 nm to 800 nm, and more preferably 100 nm to 600 nm.

[0027] Furthermore, the first pattern structure includes an X-shaped pattern structure and a deformed Y-shaped pattern structure. In a predetermined direction parallel to the light-emitting surface, the deformed Y-shaped pattern is a shape formed by rotating the Y-shaped pattern 90° clockwise. And the X-shaped pattern structure and the deformed Y-shaped pattern structure are alternately arranged along the predetermined direction. Each X-shaped pattern structure and the adjacent Y-shaped pattern structure form one unit with a spacing of 1 to 500 nm. A plurality of units are arranged periodically. The periods in the predetermined direction and the direction perpendicular to the predetermined direction are both 1 nm to 1 μm. Preferably, the spacing between the X-shaped pattern structure and the Y-shaped pattern structure in one unit is 10 to 100 nm, and more preferably 30 to 50 nm. Preferably, the period is 50 to 500 nm, and more preferably 100 to 300 nm. The dimension of the first pattern structure is particularly preferably 450 to 550 nm.

[0028] In some cases, the plurality of first pattern structures included in the first metasurface structure may be the same. The first metasurface structure may be an aperiodic structure. However, preferably, the above X-shaped pattern structure, deformed Y-shaped pattern structure, and periodic arrangement are selected.

[0029] In one embodiment, the first metasurface conductive structure layer further includes a transparent medium layer laminated on the first conductive layer.

[0030] In one embodiment, the metasurface structure includes a second metasurface structure, the transparent medium layer includes a plurality of second pattern structures, and the plurality of second pattern structures are distributed along a direction parallel to the light emitting surface to form a second metasurface structure.

[0031] Furthermore, in the direction parallel to the light emitting surface, the dimension of the second pattern structure is 1 nm to 1 μm, preferably 50 nm to 900 nm, and more preferably 50 nm to 500 nm.

[0032] In some cases, the second pattern structure includes a circular pattern structure with a deformed F-shaped through hole embedded in the center. In a predetermined direction parallel to the light emitting surface, the deformed F shape is a shape formed by rotating the F shape 30° clockwise. The dimension of the deformed F shape is 1 to 200 nm, preferably 10 to 100 nm, and more preferably 10 to 50 nm. The plurality of circular pattern structures are arranged periodically, and the periods in the predetermined direction and the direction perpendicular to the predetermined direction are both 1 nm to 1 μm, preferably 5 to 300 nm, and more preferably 10 to 100 nm. Particularly preferably, the diameter of the circular pattern structure is 50 to 150 nm.

[0033] Alternatively, in some cases, the second pattern structure includes a deformed K-shaped pattern structure and a deformed L-shaped pattern structure. In a predetermined direction parallel to the light emitting surface, the deformed K-shaped pattern is a shape formed by rotating the K-shaped pattern counterclockwise by 45°, and the deformed L-shaped pattern is a shape formed by mirror-inverting the L-shaped pattern. The deformed K-shaped pattern structure and the deformed L-shaped pattern structure are alternately arranged along the predetermined direction. Each deformed L-shaped pattern structure adjacent to the deformed K-shaped pattern structure forms a unit with a spacing of 1 to 200 nm (preferably 10 to 100 nm, more preferably 10 to 50 nm). A plurality of the units are periodically arranged. The periods in the predetermined direction and the direction perpendicular to the predetermined direction are both 1 to 500 nm, preferably 50 to 200 nm, and more preferably 100 to 200 nm. Particularly preferably, the dimensions of the deformed K-shaped pattern structure and the deformed L-shaped pattern structure are 50 to 150 nm.

[0034] Alternatively, in some cases, the second pattern structure is a regular hexagonal pattern structure with an H-shaped through hole embedded in the center. The dimensions of the H-shaped through hole are 1 to 200 nm, preferably 10 to 100 nm, and more preferably 10 to 50 nm. In a predetermined direction parallel to the light emitting surface, two adjacent regular hexagonal pattern structures form a unit with a spacing of 1 to 200 nm (preferably 10 to 100 nm, more preferably 50 to 100 nm). A plurality of the units are periodically arranged. The periods in the predetermined direction and the direction perpendicular to the predetermined direction are both 1 to 1000 nm, preferably 50 to 500 nm, and particularly preferably 100 to 200 nm. Particularly preferably, the diameter of the regular hexagonal pattern structure is 50 to 100 nm.

[0035] Alternatively, in some cases, the second pattern structure includes an elliptical pattern structure, the major axis dimension of the ellipse is 1 to 1000 nm (preferably 50 to 500 nm, more preferably 100 to 200 nm), and it is parallel to a predetermined direction on the light emitting surface. The minor axis dimension is 1 to 1000 nm (preferably 10 to 500 nm, more preferably 10 to 200 nm, particularly preferably 50 to 100 nm). A V-shaped through hole and an X-shaped through hole are respectively provided on both sides of the minor axis. The dimensions of the V shape and the X shape are 1 to 500 nm (preferably 10 to 100 nm, more preferably 10 to 50 nm). The interval between the V-shaped through hole and the X-shaped through hole is 1 to 500 nm (preferably 10 to 200 nm, more preferably 30 to 80 nm). Two adjacent elliptical pattern structures form a unit with a spacing of 1 to 500 nm (preferably 10 to 200 nm, more preferably 50 to 100 nm). A plurality of the units are periodically arranged. The periods in the predetermined direction and the direction perpendicular to the predetermined direction are 1 to 1000 nm, preferably 10 to 500 nm, more preferably 100 to 200 nm.

[0036] Alternatively, in some cases, the second pattern structure includes a deformed zigzag pattern structure, a deformed T-shaped pattern structure, a deformed M-shaped pattern structure, and a P-shaped pattern structure. The deformed zigzag pattern structure and the deformed T-shaped pattern structure are alternately arranged along a predetermined direction parallel to the light-emitting surface. The deformed M-shaped pattern structure and the P-shaped pattern structure are also alternately arranged along the predetermined direction. The P-shaped pattern structure and the deformed Z-shaped pattern structure are alternately arranged in a direction perpendicular to the predetermined direction. The deformed M-shaped pattern structure and the deformed T-shaped pattern structure are alternately arranged in a direction perpendicular to the predetermined direction. Each deformed zigzag pattern structure adjacent to a deformed T-shaped pattern structure, one deformed M-shaped pattern structure, and one P-shaped pattern structure form one unit. The distance between any two pattern structures in each unit in the predetermined direction and the direction perpendicular to the predetermined direction is 1 to 200 nm (preferably 10 to 100 nm, more preferably 30 to 80 nm). A plurality of the units are periodically arranged, and the period in the predetermined direction and the direction perpendicular to the predetermined direction is 1 to 1000 nm, preferably 10 to 500 nm, more preferably 100 to 300 nm. Particularly preferably, the dimensions of the deformed zigzag pattern structure, the deformed T-shaped pattern structure, the deformed M-shaped pattern structure, and the P-shaped pattern structure are 100 to 200 nm.

[0037] In some cases, the second metasurface structure may be an aperiodic structure.

[0038] In one embodiment, the metasurface structure is a first metasurface structure formed on a first conductive layer and used to modulate at least one of the emission angle and wavelength of the light emitted from the light-emitting surface, and a second metasurface structure used to modulate the other of the emission angle and wavelength of the light emitted from the light-emitting surface, and includes.

[0039] Exemplarily, in the first case, the first metasurface structure is used to modulate the emission angle of the light emitted from the light emitting surface to enhance the collimation of the light emitted from the Micro-LED chip. At the same time, the second metasurface structure is used to modulate the wavelength of the light emitted from the light emitting surface, that is, to change the wavelength of the emitted light to achieve the color change effect of the Micro-LED chip. Or, it may be the second case, that is, the first metasurface structure is used to modulate the wavelength of the light emitted from the light emitting surface, and the second metasurface structure is used to modulate the emission angle of the light emitted from the light emitting surface. Surprisingly, compared with the first case, in the second case, the structure of the Micro-LED chip is simpler, forms wavelength color modulation, increases the color gamut with high saturation while improving the emission brightness, and can obtain a more uniform observation effect.

[0040] Furthermore, the material of the transparent media layer includes, but is not limited to, any one or a combination of silicon oxide, silicon nitride, aluminum nitride, aluminum oxide, gallium oxide, titanium oxide, hafnium oxide.

[0041] Furthermore, the thickness of the transparent media layer is 0.1 nm to 1 μm, preferably 20 nm to 600 nm, and more preferably 100 to 400 nm. In the above first case, when using the transparent media layer with the more preferred thickness, the emission brightness and hue saturation of the Micro-LED chip will be higher, and the emission uniformity will be better.

[0042] In one embodiment, the Micro-LED chip further includes a second metasurface conductive structure layer. The LED chip structure has a first surface and a second surface opposite to the first surface. The first surface is the light emitting surface, and the second surface is electrically joined to the LED driving mechanism through a second conductive layer.

[0043] In one embodiment, the second surface of the LED chip structure is electrically joined to an LED driving mechanism via a second metasurface conductive structure layer, and the second metasurface conductive structure layer includes the second conductive layer and a third metasurface structure. The third metasurface structure is provided on a side surface of the second conductive layer close to the LED chip structure or on the second surface of the LED chip structure, and is used to at least reflect light emitted from the LED chip structure to the second metasurface conductive structure layer.

[0044] Furthermore, the third metasurface structure includes a plurality of third pattern structures distributed along a direction parallel to the second surface. In the direction parallel to the second surface, the dimension of the third pattern structure is 1 nm to 1 μm, preferably 80 nm to 800 nm, and more preferably 150 nm to 650 nm.

[0045] Furthermore, the third pattern structure includes an equilateral triangle pattern structure and a deformed equilateral triangle pattern structure. The equilateral triangle pattern structure and the deformed equilateral triangle pattern structure are alternately arranged along a predetermined direction parallel to the second surface. A deformed X-shaped through hole is embedded in the center of the equilateral triangle pattern structure. The deformed X shape is a shape formed by rotating the X shape clockwise by 45°. A deformed Z-shaped through hole is embedded in the center of the deformed equilateral triangle pattern structure. The deformed equilateral triangle is a shape formed by rotating the equilateral triangle clockwise by 90° around a specified point. The deformed Z shape is a shape formed by rotating the Z shape clockwise by 45°. The line segment lengths of the deformed X shape and the deformed Z shape are 1 nm to 500 nm, preferably 10 to 200 nm, and more preferably 50 to 100 nm. The midpoint of one side of each equilateral triangle pattern structure intersects with one vertex of the adjacent deformed equilateral triangle pattern structure at the specified point to form one unit, and a plurality of the units are arranged periodically. The period in the predetermined direction is 1 nm to 1 μm, preferably 50 to 500 nm, and more preferably 100 to 500 nm. The period in the direction perpendicular to the predetermined direction is 1 nm to 1 μm, preferably 50 to 500 nm, and more preferably 100 to 500 nm.

[0046] Furthermore, the plurality of the third pattern structures included in the third metasurface structure may be the same or different, and the third metasurface structure may be a periodic or aperiodic structure.

[0047] Furthermore, the LED driving mechanism may include, but is not limited to, a CMOS or TFT driving mechanism integrally provided with a driving substrate or the like.

[0048] Furthermore, the second conductive layer may be made of a metal material, for example, any one or a combination of indium, tin, silver, platinum, gold, titanium, aluminum, nickel, chromium, molybdenum, and copper, or may be a non-metal material such as ITO, graphene, carbon nanotube, or conductive polymer, and is not limited thereto. More preferably, the second conductive layer is formed by selecting a metal material having good thermal conductivity, conductivity, and light reflection performance, such as metal aluminum, indium, tin, silver, or gold.

[0049] Furthermore, the thickness of the second conductive layer is set according to actual needs. For example, it may be 1 nm or more, 10 nm or more, 100 nm or more, 500 nm or more, or 1 μm or more, but it should not be too thick so as not to cause a significant increase in the thickness and cost of the entire Micro-LED chip.

[0050] In one embodiment, the LED chip structure includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer laminated along a set direction, and a side surface of the first doped semiconductor layer or the second doped semiconductor layer away from the active layer is the light emitting surface.

[0051] In one embodiment, the first conductive layer forms an ohmic contact with the light emitting surface of the LED chip structure, for example, forms an ohmic contact with the first doped semiconductor layer or the second doped semiconductor layer.

[0052] In one embodiment, the Micro-LED chip includes a plurality of LED chip structures, and the plurality of LED chip structures are arranged in an array, that is, an LED chip array is formed. Here, each LED chip structure may be used as one pixel point, or a plurality of adjacent LED chip structures may be used as one pixel point. Exemplarily, the plurality of LED chip structures are set into a plurality of groups, each group includes three blue light LED chip structures, and by providing different first metasurface conductive structure layers on the three LED chip structures respectively, the three pixel points corresponding to the three LED chip structures are rendered in three colors of blue, red, and green respectively. Compared with the Micro-LED full-color display resolution based on macro transfer technology and quantum dot film color conversion technology, the full-color display resolution of the present application has many advantages such as simple structure, low cost, high yield, good process controllability, and environmental protection.

[0053] Furthermore, the Micro-LED chip may include a light insulation structure in order to better remove the optical crosstalk between adjacent LED chip structures and improve the display effects such as the contrast and brightness of the Micro-LED chip. Taking the case where the surface of the second doped semiconductor layer is the light emitting surface as an example, the light insulation structure includes an ion implantation region, an insulation groove, and a light shielding structure distributed in the Micro-LED chip. The ion implantation region continuously extends at least from the top end surface of the second doped semiconductor layer to the inside of the first doped semiconductor layer to electrically insulate any two adjacent LED chip structures from each other. The entire insulation groove is located within the ion implantation region, the groove opening is provided on the top end surface of the second doped semiconductor layer, the groove bottom surface is located inside the first doped semiconductor layer and is higher than the bottom end surface of the ion implantation region. The light shielding structure is provided in the insulation groove and is used to prevent light from transmitting between any two adjacent LED chip structures through the second doped semiconductor layer and the active layer.

[0054] Here, an ion implantation insulation method is adopted to realize an LED chip array. By opening an insulation groove in the ion implantation region and providing a light-shielding structure in the insulation groove, chip miniaturization can be better realized, damage to the chip sidewalls and hang keys caused by the etching process can be avoided, the quantum efficiency and effective usage area of the chip can be protected and improved, and better optical and electrical characteristics can be achieved. At the same time, light transmission between adjacent chips in the LED chip array can be effectively blocked, optical crosstalk can be removed, and display effects such as the contrast and brightness of the LED chip array can be improved. By adopting the method of arranging the entire insulation groove within the ion implantation region, the risk of damage to the semiconductor material due to over-etching during the manufacturing process of the insulation groove can be further reduced. On the other hand, the ion implantation region can be used to electrically insulate the conductive filling material in the insulation groove from the semiconductor material in structural layers such as the second doped semiconductor layer and the active layer, thereby protecting the normal operating performance of the device.

[0055] Here, the implanted ions for forming the ion implantation region include, but are not limited to, H ions, F ions, N ions, or O ions. The ion implantation region may be one or more. Exemplarily, on the surface of the Micro-LED chip, the ion implantation region may be grid-shaped, and the region surrounded by each grid is a non-ion implantation region, which is used for fabricating the LED chip structure. Correspondingly, the insulation groove may be one or more. Exemplarily, the surface of the Micro-LED chip may also appear as a grid structure.

[0056] Here, the ion implantation region may be provided around the corresponding non-ion implantation region, and an LED chip structure is formed in the corresponding non-ion implantation region. The dimensions of the ion implantation region and the LED chip structure may both be set according to actual needs. Exemplarily, the dimensions of the ion implantation region and the LED chip structure are 1 μm to 50 μm. Here, the dimensions of the ion implantation region and the LED chip structure may mainly refer to the dimensions in the direction parallel to the layer plane of the LED chip structure, which may be its length and width or diameter.

[0057] Here, the inner wall of the insulating groove is at a certain distance from the outer wall of the corresponding ion implantation region, that is, the ion implantation region has a certain wall thickness, which may be, for example, 100 nm to 20 μm.

[0058] Here, the Micro-LED chip may further include at least one thermally conductive medium layer. The thermally conductive medium layer is at least continuously covered on the side wall of the insulating groove, located between the side wall of the insulating groove and the light-shielding structure, and the light-shielding structure includes a metal light-insulating layer that is at least continuously covered on the medium layer. Here, by providing the thermally conductive medium layer, the protection of the side wall of the insulating groove can be achieved. On the other hand, the conductive filling material in the insulating groove can be further electrically insulated from the semiconductor materials in the structural layers such as the second doped semiconductor layer and the active layer. In addition, when using the thermally conductive medium layer to fabricate the metal light-insulating layer by processes such as evaporation, the escape of ions in the ion implantation region can be prevented, and the operating performance of the device can be better protected.

[0059] Here, the material of the thermally conductive medium layer includes, but is not limited to, silicon oxide, silicon nitride, aluminum nitride, aluminum oxide, gallium oxide, titanium oxide, or hafnium oxide. The thickness of the thermally conductive medium layer is 5 nm to 500 nm.

[0060] More preferably, the Micro-LED chip includes a plurality of thermally conductive medium layers having different refractive indexes. The plurality of thermally conductive medium layers are at least sequentially laminated on the side wall of the insulating groove to form a distributed Bragg reflector structure (DBR) in combination with the ion implantation region. Here, the definition of the distributed Bragg reflector structure is known in the technical field and is mainly an optical thin film formed by different laminated combinations of low refractive index materials and high refractive index materials. Exemplarily, the low refractive index material may be selected as SiO2, etc., but is not limited thereto, and the high refractive index material may be selected from TiO2, Ta2O5, ZrO2, etc., but is not limited thereto. The greater the refractive index difference between the materials, the smaller the thickness required to achieve the desired reflectivity.

[0061] Specifically, after forming an ion implantation region by ion implantation in the selected region of the LED chip structure, the refractive index of the semiconductor material also changes, and it cooperates with the semiconductor material in the chip to form a light refractive interface. By alternately laminating a plurality of medium layers having different refractive indices on the sidewalls of the insulating grooves, a DBR structure can be formed while achieving sidewall passivation, which can more reliably ensure the stability and long-term reliability of the electrical performance of the optoelectronic chip. In cooperation with the light shielding structure, the light emitted from the sidewall of the optoelectronic chip can be optically insulated and completely reflected, so that more light can be emitted from the front side of the optoelectronic chip, the optical crosstalk problem can be better solved, and the photoelectric conversion efficiency of the chip can be further improved.

[0062] Here, the material of the metal light insulation layer includes, but is not limited to, gold, titanium, aluminum, nickel, chromium, molybdenum or copper. Preferably, the metal light insulation layer is formed of a metal or alloy having excellent reflection performance and conductivity such as Al. The metal light insulation layer may have a single-layer or multi-layer structure. More preferably, the thermal expansion coefficient of the thermal conductive medium material for forming the thermal conductive medium layer is between the thermal expansion coefficient of the material constituting the metal light insulation layer and the thermal expansion coefficient of the material constituting the ion insulation region, and / or the thermal conductive medium material has good bonding properties with both the material constituting the metal light insulation layer and the material constituting the ion insulation region. This not only helps to transfer the heat generated by the operation of the chip more quickly, but also makes the metal light insulation layer and the chip more firmly bonded, and can avoid the metal light insulation layer peeling off from the chip structure under the influence of the heat generated by the chip after a long period of operation. The thermal conductive medium material may be selected from, but is not limited to, silicon nitride, aluminum nitride, etc.

[0063] More preferably, the medium layer for forming the distributed Bragg reflector structure is formed of the thermal conductive medium material in order to have the functions of light reflection and heat conduction.

[0064] Here, the Micro-LED chip may further include a thermally conductive passivation layer, the thermally conductive passivation layer covers the surface of the LED chip structure, and is thermally conductively connected to the metal optical insulation layer. By using the thermally conductive passivation layer, not only can the surface of the LED chip array be protected, but also a heat conduction path can be formed in cooperation with the metal optical insulation layer, further reducing the temperature of the LED chip array and ensuring its working performance and stability. The material of the thermally conductive passivation layer includes, but is not limited to, aluminum nitride, boron nitride, diamond, etc.

[0065] In some cases, a local region of the thermally conductive passivation layer is filled in the insulating groove and is in direct contact with the metal optical insulation layer. Also, in some cases, several windows may be opened on the thermally conductive passivation layer to fabricate electrodes adapted to each LED chip structure.

[0066] In some cases, the metal optical insulation layer may further extend to cover the surface of the LED chip structure to form a current spreading layer.

[0067] In the present application, the material of the LED chip structure includes group III-V compounds, preferably group III nitrides, such as Al x In y Ga 1-x-y N, where 1≧x≧0, 1≧y≧0, 1≧(1 - x - y)≧0. Here, the first doped semiconductor layer and the second doped semiconductor layer have different conductivity types. For example, the first doped semiconductor layer and the second doped semiconductor layer may be an N-type semiconductor layer and a P-type semiconductor layer respectively, or vice versa. The active layer may be a multiple quantum well layer. Further, the LED chip structure may include other structural layers common in this field, such as a buffer layer. The materials, thicknesses, etc. of these structural layers can be selected or set according to other common methods in this field, and will not be repeated here. Exemplarily, the LED chip structure may be a GaN-based LED chip structure.

[0068] In this application, the Micro-LED chip includes a substrate, such as a sapphire, Si, SiC, GaN substrate, etc., but is not limited thereto. In some cases, for example, when the Micro-LED chip has a flip-flop structure, the substrate may also be removed.

[0069] Some embodiments of this application further provide a method for fabricating the Micro-LED chip, and this method includes fabricating an LED chip structure, providing a first conductive layer and a metasurface structure on the light-emitting surface of the LED chip structure, wherein the metasurface structure is laminated on and / or integrally provided with the first conductive layer.

[0070] In one embodiment, processes such as metal-organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE) are used to sequentially grow a first doped semiconductor layer, an active layer, a second doped semiconductor layer, etc. on a substrate to form the epitaxial structure of the Micro-LED chip, and then one or more of the LED chip structures are fabricated in the epitaxial structure using processes such as lithography and etching.

[0071] In one embodiment, the metasurface structure includes a first metasurface structure, and the fabrication method specifically includes forming a plurality of first pattern structures in the first conductive layer when fabricating the first conductive layer on the light-emitting surface of the LED chip structure, and distributing the plurality of first pattern structures along a direction parallel to the light-emitting surface to form the first metasurface structure.

[0072] Furthermore, a continuous transparent medium layer can be formed on the first conductive layer by atomic layer deposition (ALD) or other physical / chemical deposition methods.

[0073] In one embodiment, the metasurface structure includes a second metasurface structure. Specifically, the manufacturing method includes providing a transparent medium layer on the first conductive layer, forming a plurality of second pattern structures within the transparent medium layer, and distributing the plurality of second pattern structures along a direction parallel to the light-emitting surface, thereby forming the second metasurface structure.

[0074] Exemplarily, first, a continuous metal layer with a thickness of 20 nm or less is fabricated as the first conductive layer on the light-emitting surface of the LED chip structure by methods such as vapor deposition or sputtering. Then, a medium layer of the second metasurface structure is formed on the first conductive layer by atomic layer deposition (ALD) or other physical / chemical deposition methods.

[0075] In one embodiment, the metasurface structure includes a first metasurface structure and a second metasurface structure. Specifically, the manufacturing method When fabricating the first conductive layer on the light-emitting surface of the LED chip structure, a plurality of first pattern structures are formed within the first conductive layer, and the plurality of first pattern structures are distributed along a direction parallel to the light-emitting surface, thereby forming the first metasurface structure. And, a transparent medium layer is provided on the first conductive layer, a plurality of second pattern structures are formed within the transparent medium layer, and the plurality of second pattern structures are distributed along a direction parallel to the light-emitting surface, thereby forming the second metasurface structure.

[0076] In this application, a patterning mask is set in advance on the light-emitting surface of the LED chip structure, and then a metal or non-metal conductive material is directly deposited on the light-emitting surface of the LED chip structure by methods such as physical / chemical deposition, thereby obtaining a first conductive layer having a first metasurface structure. Alternatively, a metal or non-metal conductive material is directly deposited on the light-emitting surface of the LED chip structure by methods such as physical / chemical deposition to form a continuous first conductive layer, and then the first conductive layer is processed using processes such as lithography and etching, so that the first conductive layer can have a first metasurface structure. For the transparent medium layer, it can also have a second metasurface structure in the same way.

[0077] In this application, after the fabrication of the first conductive layer is completed, a process such as rapid annealing is used to form an ohmic contact between the first conductive layer and the light-emitting surface of the LED chip structure, that is, the surface of the first doped semiconductor layer or the second doped semiconductor layer.

[0078] In one embodiment, the manufacturing method further includes electrically joining the side surface of the LED chip structure, which is opposite to the second surface and the light-emitting surface, to the LED driving mechanism via a second conductive layer.

[0079] Furthermore, the side surface (second surface) of the LED chip structure, which is opposite to the light-emitting surface (first surface), is electrically joined to the LED driving mechanism via a second metasurface conductive structure layer. Here, the second metasurface conductive structure layer includes the second conductive layer and a third metasurface structure, and the third metasurface structure is formed on the side surface of the second conductive layer close to the LED chip structure or on the second surface of the LED chip structure.

[0080] Exemplarily, a second conductive layer is formed on the surface of the LED driving mechanism in advance, and after a third metasurface structure is fabricated on the second conductive layer, it is joined to the second surface of the LED chip structure. Alternatively, after a third metasurface structure is fabricated on the second surface of the LED chip structure, the second surface of the LED chip structure may be joined to the LED driving mechanism via a second conductive layer. From the perspective of process controllability and the like, the latter method is more preferable.

[0081] Here, the second conductive layer may also be referred to as a metal bonding layer or a metal adhesive layer, etc., and its material includes, but is not limited to, one or a combination of In, Sn, Ag, Au, etc. Alternatively, the second conductive layer may be formed using a conductive adhesive or the like. However, from the perspective of bonding strength and thermal conductivity, etc., the former obtains better effects.

[0082] In one embodiment, the manufacturing method further includes the following: First, perform ion implantation on at least the top end surface of the second doped semiconductor layer with respect to the LED chip structure, so that the ion implantation depth reaches inside the first doped semiconductor layer, thereby forming an ion implantation region. The ion implantation region is used to electrically insulate a plurality of LED chip structures arranged in an array within the epitaxial structure. The implanted ions include, but are not limited to, H ions, F ions, N ions, or O ions. Generally, the ion implantation region is provided around the non-ion implantation region, and the LED chip structure is fabricated within the non-ion implantation region. The dimensions of the ion implantation region and the non-ion implantation region may be 1 μm to 50 μm. In order to increase the effective utilization area of the epitaxial structure, the dimension of the non-ion implantation region should be as large as possible, and the dimension of the ion implantation region should be as small as possible within a reasonable range. The reasonable range desirably satisfies the condition that electrical insulation between adjacent chip structures is achieved and the opening of the insulating groove is facilitated.

[0083] Next, perform etching on the ion implantation region. The etching depth is smaller than the ion implantation depth reaching inside the first doped semiconductor layer, and an insulating groove is formed within the ion implantation region, thereby insulating the second doped semiconductor layers and the active layers of at least any two adjacent LED chip structures from each other.

[0084] Thereafter, a light-shielding structure is provided within the insulating groove, which can prevent light from transmitting between any two adjacent LED chip structures through the second doped semiconductor layer and the active layer.

[0085] Exemplarily, an ion implantation mask with patterning may be provided on the surface of the LED chip structure in advance, and the ion implantation may be performed using the mask. The ion implantation mask may be fabricated in advance and transferred onto the surface of the LED chip structure, or a photoresist or the like may be applied to the surface of the LED chip structure and then fabricated on the surface of the LED chip structure using a lithography process or the like. The pattern and dimensions of the ion implantation mask correspond to the shape and dimensions of the ion implantation region and may be set according to actual needs. For example, the ion implantation region may have a circular, rectangular, or other regular or irregular shape.

[0086] Exemplarily, an etching operation such as RIE, ECR, or ICP may be used to etch the ion implantation region to form the insulating groove. Further, an etching mask may be provided on the ion implantation region, and an etching operation may be performed using the etching mask to more accurately control the position, dimensions, and shape of the insulating groove and avoid damage to the sidewalls of the chip structure. More preferably, the distance between the edge of the opening on the etching mask and the edge of the ion implantation region may be controlled to be 100 nm to 20 μm, and the distance between the inner wall of the etched insulating groove and the outer wall of the corresponding ion implantation region may be 100 nm to 20 μm. In actual manufacturing, the interval between the high-resistance ion implantation regions can be accurately adjusted by changing the dimensions of the ion implantation mask and the etching mask, the characteristic dimensions of the chip can be flexibly defined, and the fabrication of devices with dimensions ranging from micrometers to hundreds of micrometers can be achieved.

[0087] Furthermore, the manufacturing method may further include fabricating at least one thermally conductive medium layer, and the thermally conductive medium layer continuously covering at least the sidewalls of the insulating groove, fabricating a metal light-insulating layer, and the metal light-insulating layer continuously covering at least the thermally conductive medium layer to form the light-shielding structure.

[0088] In the above embodiments of the present application, the thermally conductive medium layer may be grown by a process such as atomic layer deposition (ALD), and its thickness may be set to 5 nm to 500 nm.

[0089] More preferably, a plurality of thermally conductive medium layers having different refractive indexes and alternately laminated at least on the side walls of the insulating grooves may be provided, and a distributed Bragg reflector structure may be formed by combining the plurality of thermally conductive medium layers and the ion implantation region.

[0090] Furthermore, a thermally conductive passivation layer may be further formed on the surface of the LED chip structure, and the thermally conductive passivation layer and the metal optical insulation layer may be thermally conductively connected. The thermally conductive passivation layer may be formed by growth by a process such as atomic layer deposition (ALD). Preferably, the entire thermally conductive passivation layer can cover the surface of the LED chip structure. Of course, when manufacturing electrodes or the like, windows corresponding to the thermally conductive passivation layer can also be opened.

[0091] Furthermore, the metal optical insulation layer extends to cover the surface of the LED chip structure to form a current spreading layer, thereby contributing to improving the light emission uniformity of the LED chip array.

[0092] By adopting the above method, the device optical crosstalk problem can be effectively eliminated, the device light emission efficiency can be improved while increasing the effective use area of the chip, and the effects such as the damage effect of the material side wall can be achieved, and a Micro-LED chip with smaller size, better optical characteristics (resolution, luminance, etc.) and electrical characteristics can be easily obtained.

[0093] Furthermore, electrodes and the like that are compatible with the LED chip structure can be manufactured by methods well known in the art so that the Micro-LED chip can operate normally.

[0094] Obviously, a method for improving the light emission efficiency and light emission direction of a Micro-LED chip through a resonator structure or a lens system, and compared with the full-color display resolution by macro transfer or quantum dot film color conversion technology, the method of the present application is adapted to large-scale standard semiconductor process processes, with significantly lower process difficulty, higher controllability, safer and more environmentally friendly, smaller device structure changes, suitable for lightweight applications, lower cost, higher yield rate, improved device quality, and can better meet the application needs suitable for ultra-high resolution displays.

[0095] Incidentally, the method of the present application is also suitable for the fabrication of micro-nano size optoelectronic devices such as Mini-LED chips.

[0096] Some embodiments of the present application further provide a Micro-LED device including the above Micro-LED chip. The Micro-LED device may be, but is not limited to, a lighting device, a display device, etc.

[0097] Hereinafter, the embodiments of the present application will be described by specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied in other different specific embodiments, and various details in this specification can be modified or changed in various ways without departing from the spirit of the present application based on different viewpoints and applications.

[0098] When the embodiments of the present application are described in detail, for the convenience of description, the cross-sectional view of the display device structure is partially enlarged without following the general scale, and the schematic diagram is merely an example and does not limit the protection scope of the present application. Also, in actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0099] To facilitate the description, spatial relationship terms such as "under", "below", "lower than", "bottom surface", "above", "on", etc. are used to describe the relationship between one device or feature shown in the accompanying drawings and other devices or features. It should be understood that these spatial relationship terms are intended to include directions other than the direction depicted in the accompanying drawings for the device during use or operation. Further, when a layer is referred to as being "between" two layers, it may be the only layer between the two layers, or one or more intermediate layers may be interposed.

[0100] In the context of this application, a structure in which a first feature described is "above" a second feature may form an embodiment where the first and second features are in direct contact, or may be an embodiment where another feature is formed between the first and second features. Thus, it is possible that the first and second features may not be in direct contact.

[0101] Note that the illustrations provided in this embodiment are merely schematic diagrams for explaining the basic concept of this application. The illustrations show only the relevant components of this application and are not drawn according to the number, shape, and dimensions of the components during actual implementation. It should be noted that the form, number, and ratio of each component can be arbitrarily changed during actual implementation, and the layout of its constituent elements may also become more complex.

[0102] (Example 1) Referring to FIG. 1, this embodiment provides a Micro-LED chip, which includes a sapphire substrate 10 and an LED chip structure 11. The LED chip structure is Al grown sequentially on the substrate from bottom to top x Ga 1-xIt includes an N (0≦x≦1) buffer layer 111, an N-type GaN layer 112, a GaN multiple quantum well active layer (GaN MQWs) 113, and a P-type GaN layer 114. The GaN MQWs layer 113 emits blue light with a wavelength of about 450 nm. Further, the surface of the P-type GaN layer 114 is the light-emitting surface of the LED chip structure, and a first metasurface conductive structure layer is further provided on the surface of the P-type GaN layer 114. The first metasurface conductive structure layer is a p-type electrode 115, that is, an Au / Ni metal layer (the first conductive layer), with a thickness of about 50 nm. It has a first metasurface structure composed of a plurality of first pattern structures 1151 periodically arranged on the surface of the P-type GaN layer 114. As shown in FIG. 2, there are two types of the first pattern structures. In a predetermined direction parallel to the light-emitting surface, one is in an X shape (referred to as an X-shaped pattern structure), and the other is a shape formed by rotating a Y shape 90° clockwise (referred to as a deformed Y-shaped pattern structure). The dimensions of the X-shaped pattern structure and the deformed Y-shaped pattern structure are both about 500 nm. Both are arranged alternately along the predetermined direction. One Y-shaped pattern structure adjacent to one X-shaped pattern structure forms a unit with a spacing of 40 nm. A plurality of units are arranged periodically. The periods in the predetermined direction and the direction perpendicular to it are both about 140 nm. The Au / Ni metal layer forms an ohmic contact with the P-type GaN layer 114. At the same time, the LED chip structure 11 has a mesa structure, and its n-type electrode 116 may be a Ti / Al / Ni / Au layer, or a conductive layer made of materials such as indium tin oxide (ITO), indium (In), tin (Sn), silver (Ag), platinum (Pt), gold (Au), titanium (Ti), aluminum (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), or copper (Cu), which forms an ohmic contact with the N-type GaN layer 112. Compared with a Micro-LED chip using a continuous ITO conductive layer or a continuous Au / Ni metal layer with a thickness of 20 nm or less as the p-type electrode, the Micro-LED chip of this embodiment employs the first metasurface conductive structure layer and emits green light with a wavelength of about 550 nm.

[0103] The manufacturing method of the Micro-LED chip includes the following steps: S1. An AlN buffer layer 111, an N-type GaN layer 112, a multiple quantum well active layer 113, and a P-type GaN layer 114 are sequentially grown on a sapphire substrate by MOCVD, MBE, PECVD, etc., to obtain an epitaxial wafer shown in FIG. 3.

[0104] S2. By processes such as lithography, dry or wet etching processes, etc., the P-type GaN layer 114, the GaN MQWs layer 113, and a part of the N-type GaN layer 112 are removed through patterning, that is, after patterning, the P-type GaN layer 114 layer and the N-type GaN layer 112 are exposed to form a mesa structure. An ohmic contact is formed on the surface of the N-type GaN layer 112 by processes such as metal thin film deposition and rapid annealing. The n-type electrode 116, which is an ohmic contact metal, may have a structure such as Ti / Al / Ni / Au or a similar structure. The thickness of each layer is less than 500 nm, the rapid annealing temperature is 500°C to 1000°C, and the annealing time is 180 s or less.

[0105] S3. A patterning deposition mask is provided on the top surface of the P-type GaN layer 114, and Au / Ni metal is deposited on the top surface of the P-type GaN layer 114 by evaporation to form a p-type electrode 115 having a first metasurface structure.

[0106] (Example 2) The structure of the Micro-LED chip provided in this example is basically the same as that of Example 1 except for the following points. The p-type electrode adopts an Au / Ni metal layer with a thickness of about 10 nm, and the dimensions and periods of the first pattern structure in the first metasurface structure of the p-type electrode are also the same as those in Example 1.

[0107] Compared with a Micro-LED chip using a continuous Au / Ni metal layer with a thickness of about 10 nm as the p-type electrode, the Micro-LED chip of this example emits green light with a wavelength of about 550 nm by using the first metasurface conductive structure layer. Compared with the Micro-LED chip of Example 1, the emission luminance of the Micro-LED chip of this example is significantly improved.

[0108] (Example 3) The structure of the Micro-LED chip provided by this embodiment is basically the same as that of Example 2, except for the following points. A continuous transparent silicon oxide (SiO2) thin film with a thickness of about 1 μm is further covered on the p-type electrode.

[0109] Compared with the Micro-LED chip of Example 2, the light emission uniformity of the Micro-LED chip of this embodiment is better.

[0110] (Example 4) The structure of the Micro-LED chip provided by this embodiment is basically the same as that of Example 1, except for the following points. Referring to FIG. 4, a transparent silicon oxide (SiO2) thin film 117 with a thickness of about 1 μm is further covered on the p-type electrode 115. The SiO2 thin film has a second metasurface structure composed of a plurality of second pattern structures 1171 periodically arranged on the upper surface of the p-type electrode. The second pattern structure is a circular pattern structure with a deformed F-shaped through hole embedded in the center. The diameter of the circular pattern structure is 100 nm. In a predetermined direction parallel to the light-emitting surface, the shape of the deformed F-shaped through hole is a shape formed by rotating the F shape 30° clockwise. Its lateral dimension is about 30 nm and its longitudinal dimension is about 40 nm. The periods in the predetermined direction and the direction perpendicular to it are both about 50 nm.

[0111] The manufacturing method of the Micro-LED chip is also basically the same as that of Example 1, and the difference further includes the following steps: S4. After depositing a continuous SiO2 thin film on the p-type electrode by a process such as ALD, the SiO2 thin film is patterned by a lithography and dry etching process to form the second metasurface structure.

[0112] Compared with Example 1, the Micro-LED chip of this embodiment adopts the first metasurface structure and the second metasurface structure, so that not only green light with a wavelength of about 550 nm is emitted, but also the collimation and light extraction efficiency of the device are significantly improved. In particular, the chroma and contrast of the color presented by the device are higher.

[0113] (Example 5) The structure of the Micro-LED chip provided by this example is basically the same as that of Example 4, except for the following points. The first metasurface structure is the same as the second metasurface structure in Example 4, and the second metasurface structure is the same as the first metasurface structure in Example 4.

[0114] The operating performance of the Micro-LED chip in this example is the same as that of Example 4, but the chroma and contrast of the color presented during operation decrease to a certain extent.

[0115] (Example 6) The structure of the Micro-LED chip provided by this example is basically the same as that of Example 4, except for the following points. The second pattern structure has two shapes, a deformed K shape and a deformed L shape. In the predetermined direction, the deformed K shape is a shape formed by rotating the K shape counterclockwise by 45°, and the deformed L shape is a shape formed by mirror-inverting the L shape. The dimensions of both pattern structures are about 100 nm, and they are arranged alternately along the predetermined direction. A deformed L-shaped pattern structure adjacent to a deformed K-shaped pattern structure forms a unit with a spacing of about 30 nm, and a plurality of units are arranged periodically. The periods in the predetermined direction and the direction perpendicular to it are both about 130 nm. The light emitted from the Micro-LED chip is mainly green light with a wavelength of about 550 nm, but the collimation and light extraction efficiency of the device are inferior to those of the device in Example 4.

[0116] (Example 7) The structure of the Micro-LED chip provided by this embodiment is basically the same as that of Embodiment 2, except for the following points. A transparent silicon oxide (SiO2) thin film with a thickness of about 1 μm is further covered on the p-type electrode. The SiO2 thin film has a second metasurface structure composed of a plurality of second pattern structures periodically arranged on the upper surface of the p-type electrode. The second pattern structure is a regular hexagonal pattern structure with an H-shaped through hole embedded in the center. The diameter of the regular hexagonal pattern structure is 80 nm, and both the lateral dimension and the longitudinal dimension of the H-shaped through hole are about 35 nm. In the predetermined direction, two adjacent regular hexagonal pattern structures form a unit with a spacing of about 60 nm. A plurality of units are periodically arranged, and the periods in the predetermined direction and the direction perpendicular thereto are both about 140 nm.

[0117] Compared with Embodiment 2 and Embodiment 3, the Micro-LED chip of this embodiment adopts the first metasurface structure and the second metasurface structure, so that not only green light with a wavelength of about 550 nm is emitted, but also the collimation and light extraction efficiency of the device are significantly improved. In particular, the chroma and contrast of the color presented by the device are also higher.

[0118] (Embodiment 8) The structure of the Micro-LED chip provided by this embodiment is basically the same as that of Embodiment 4, except for the following points. Referring to FIG. 5, the Au / Ni metal layer 115′ is continuous and has a thickness of about 10 nm. In the second metasurface structure of the SiO2 thin film 117′, in a predetermined direction parallel to the light-emitting surface, the second pattern structure 1171′ is elliptical, with its major axis being about 120 nm and parallel to the predetermined direction, the minor axis being about 80 nm, and a V-shaped through-hole and an X-shaped through-hole are respectively formed on both sides of the minor axis. The dimension of the V-shaped through-hole is about 25 nm, the dimension of the X-shaped through-hole is about 40 nm, the distance between the V-shaped through-hole and the X-shaped through-hole is about 50 nm, and two adjacent ellipses form a unit with a spacing of about 60 nm. A plurality of units are arranged periodically, the period in the predetermined direction is about 180 nm, and the period in the direction perpendicular to the predetermined direction is about 140 nm. By adopting the second metasurface structure, the Micro-LED chip of this embodiment emits red light with a wavelength of about 650 nm, has low optical energy loss emitted from the active region, is emitted with good directivity, and also has high collimation and light emission efficiency.

[0119] (Embodiment 9) The structure of the Micro-LED chip provided by this embodiment is basically the same as that of Example 8, except for the following points. In the second metasurface structure of the SiO2 thin film, in a predetermined direction parallel to the light-emitting surface, the second pattern structure has four shapes: a deformed zigzag, a deformed T-shape, a deformed M-shape, and a P-shape pattern structure, and the dimensions of these four pattern structures are all about 150 nm. Among them, the deformed zigzag and deformed T-shape pattern structures are alternately arranged along the predetermined direction, the deformed M-shape and P-shape pattern structures are also alternately arranged along the predetermined direction, the P-shape and deformed Z-shape pattern structures are alternately arranged in a direction perpendicular to the predetermined direction, and the deformed M-shape and deformed T-shape pattern structures are alternately arranged in a direction perpendicular to the predetermined direction. Four pattern structures of adjacent deformed Z-shape, deformed T-shape, deformed M-shape, and P-shape pattern structures form one unit, and the distance between two adjacent pattern structures in the predetermined direction and the distance between two adjacent pattern structures in the direction perpendicular thereto are both about 50 nm. A plurality of units are arranged periodically, and the periods in the predetermined direction and the direction perpendicular thereto are both about 200 nm. By adopting the second metasurface structure, the Micro-LED chip of this embodiment still emits blue light, but compared with a control product that does not adopt the second metasurface structure, its collimation, brightness, and light emission uniformity are significantly improved.

[0120] (Example 10) Referring to FIGS. 6 and 7, the Micro-LED chip provided by this embodiment includes an LED chip structure 21, and the LED chip structure includes an N-type GaN layer 211, a GaN multiple quantum well active layer (GaN MQWs) 212, and a P-type GaN layer 213. The GaN MQWs layer 212 emits blue light with a wavelength of about 450 nm. Further, the surface of the N-type GaN layer 211 is the light-emitting surface of the LED chip structure, and a first metasurface conductive structure layer 214 is further provided on the surface of the N-type GaN layer 211. The first metasurface conductive structure layer includes an n-type electrode 2141 and a transparent silicon oxide layer 2142 laminated on the n-type electrode 2141. The n-type electrode 2141 and the transparent silicon oxide layer 2142 have the same first metasurface structure and second metasurface structure as those in Example 4 respectively, and the n-type electrode 2141 forms an ohmic contact with the N-type GaN layer 211. At the same time, the P-type GaN layer 213 is bonded to the driving substrate 216 through a metal adhesion layer 215 (i.e., the second conductive layer), and is electrically connected to a CMOS (complementary metal oxide semiconductor) or TFT (thin film field effect transistor) driving circuit in the driving substrate.

[0121] The manufacturing method of the Micro-LED chip includes the following steps: S1. An AlN buffer layer, an N-type GaN layer, a multiple quantum well active layer, and a P-type GaN layer are sequentially grown on a silicon substrate by MOCVD, MBE, PECVD, etc. to form an epitaxial wafer having a structure as shown in FIG. 3.

[0122] S2. The P-type GaN layer of the epitaxial wafer is bonded to a temporary substrate of the same size by a process such as temporary bonding. The temporary substrate may be a silicon or sapphire substrate, and the bonding force includes the bonding force provided by a lossless bonding material such as electrostatic force and photoresist, but is not limited thereto. The epitaxial wafer can be released from the temporary substrate without damage by a debonding process.

[0123] S3. Remove the silicon substrate in the epitaxial wafer by processes such as laser lift-off, thinning, and grinding, remove the AlN buffer layer by a dry etching or wet etching process, and remove some of the N-type GaN layers.

[0124] S4. Fabricate a first metasurface conductive structure layer on the surface of the remaining N-type GaN layers by the same method as in Example 4.

[0125] S5. Separate the LED chip structure in the device structure obtained in step S4 from the temporary substrate by a debonding process.

[0126] S6. Bond the P-type GaN layer to the driving substrate via a metal adhesive layer.

[0127] When using the Micro-LED chip, by applying different electrical signals to the CMOS or TFT driving circuit, the brightness, etc. of the Micro-LED chip can be controlled.

[0128] (Example 11) Referring to FIG. 8, the structure of the Micro-LED chip provided by this embodiment is basically the same as that of Embodiment 9, except for the following points. On the side surface of the P-type GaN layer 213 away from the N-type GaN layer, a third metasurface structure 217 for reflecting the light emitted from the active region to the P-type GaN layer is further formed. The third metasurface structure is composed of a plurality of third pattern structures 2171 arranged periodically. The third pattern structure has two shapes, an equilateral triangle and a deformed equilateral triangle. The side lengths of the pattern structures of both shapes are both about 100 nm, and the two are arranged alternately along a predetermined direction parallel to the side surface of the P-type GaN layer 213 away from the N-type GaN layer. Among them, a deformed X-shaped through hole is embedded in the center of the equilateral triangle pattern structure. The deformed X-shaped through hole is in a shape formed by rotating the X shape 45° clockwise, and the length of each line segment of the X shape is about 60 nm. A deformed Z-shaped through hole is embedded in the center of the deformed equilateral triangle pattern structure. The deformed equilateral triangle is the shape after the equilateral triangle rotates 90° clockwise around a specified point. The deformed Z-shaped through hole is in a shape formed by rotating the Z shape 45° clockwise, and the length of each line segment of the Z shape is also about 60 nm. The midpoint of one side of each equilateral triangle pattern structure intersects with one vertex of the adjacent deformed equilateral triangle pattern structure at the specified point to form one unit. A plurality of units are arranged periodically, the period in the predetermined direction is about 300 nm, and the period in the direction perpendicular to the predetermined direction is about 200 nm. Compared with Embodiment 4 and Embodiment 10, the Micro-LED chip of this embodiment has higher brightness and significantly improved collimation.

[0129] The manufacturing method of the Micro-LED chip is basically the same as that of Embodiment 10, and the difference further includes the following steps: S5X: After completing Step S5, the surface of the P-type GaN layer exposed by the lithography and dry etching process is patterned to form a third metasurface structure, and then Step S6 is executed.

[0130] (Embodiment 12) Referring to FIG. 9, the epitaxial structure of the Micro-LED chip provided by this embodiment includes an AlN buffer layer 311, an N-type GaN layer 312, a multi-quantum well active layer 313, and a P-type GaN layer 314 that are sequentially grown on a sapphire substrate 310. Among them, the multi-quantum well active layer emits blue light with a central wavelength of about 450 nm. The epitaxial structure includes an ion implantation region 315 and a plurality of non-ion implantation regions distributed along the layer plane direction. Any two adjacent non-ion implantation regions are electrically insulated by the ion implantation region. One LED chip structure 316 is fabricated within each non-ion implantation region, and each LED chip structure 316 can function as one pixel point, that is, there are a plurality of pixel points within the Micro-LED chip. At the same time, within the ion implantation region, an insulating groove 317 for insulating the P-type GaN layer and the multi-quantum well active layer of two adjacent LED chip structures from each other is further opened. And a light-shielding structure is further provided within the insulating groove to prevent light from transmitting between two adjacent Micro-LED chip structures through the P-type GaN layer 314 and the multi-quantum well active layer 313. Here, the light-shielding structure includes one or more layers of opaque metal light-insulating layers 318, and its material includes gold (Au), titanium (Ti), aluminum (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), copper (Cu), etc. or their alloys. The metal light-insulating layer covers the inner wall of the insulating groove and is mainly used to shield and reflect the light reflected from the multi-quantum well active layer and to block the light transfer path between adjacent Micro-LED chip structures. A thermally conductive medium layer 319 is further provided between the metal light-insulating layer and the inner wall of the insulating groove. As shown in FIG. 10, the thermally conductive medium layer is an 8-pair TiO2 / SiO2 composite layer structure, the total thickness of the thermally conductive medium layer is about 895.2 nm, the TiO2 layer 3191 and the SiO2 layer 3192 are alternately stacked to form a distributed Bragg reflector structure, the thickness of each TiO2 layer is about 41.1 nm, and the thickness of each SiO2 layer is about 70.8 nm. The reflectivity of the thermally conductive medium layer for light of different wavelengths is shown in FIG. 11.The thermally conductive media layer passivates the inner wall of the insulating groove, electrically insulates the metal optical insulating layer from the inner wall of the insulating groove, and can more thoroughly eliminate the optical crosstalk problem in cooperation with the metal optical insulating layer (such as a metal aluminum layer). At the same time, as a transition layer between the ion implantation region of the doped GaN material and the metal optical insulating layer, it can strengthen the bonding force between the metal optical insulating layer and the insulating groove wall, and cooperate with the metal optical insulating layer to construct a new heat conduction channel for the Micro-LED chip. At the same time, the metal optical insulating layer continuously extends until it covers the surface of the adjacent LED chip structure to form a current spreading layer. Further, on the current spreading layer, a transparent media layer 320 that is in direct contact with the metal optical insulating layer is further covered, and its material includes, but is not limited to, silicon oxide, titanium oxide, etc. The current spreading layer on the surface of each LED chip structure cooperates with the transparent media layer to form a first metasurface conductive structure. And the first metasurface conductive structure layers on the surfaces of three adjacent LED chip structures are different. For example, the first metasurface conductive structure layers on the surfaces of these three LED chip structures are the same as those in Examples 1, 7, and 8 respectively, that is, they emit green light, red light, and blue light respectively to realize a full-color display resolution. Here, in order to realize the first metasurface conductive structure layer similar to that in Example 1, the current spreading layer on the corresponding LED chip structure surface is subjected to patterning processing. In order to realize the first metasurface conductive structure layer similar to those in Examples 7 and 8, the thickness of the current spreading layer on the corresponding LED chip structure surface can be reduced to 20 nm or less.

[0131] As an improved embodiment, referring to Example 9 and Example 10, the sapphire substrate or the sapphire substrate and the AlN buffer layer are removed, and it may be bonded to the driving substrate through the metal adhesive layer 215 (i.e., the second conductive layer), and the N-type GaN layer is electrically connected to a CMOS (complementary metal oxide semiconductor) or TFT (thin film field effect transistor) driving circuit in the driving substrate. By applying different electrical signals to the CMOS or TFT driving circuit, the luminance of different pixels can be controlled, that is, three pixel units of red, green, and blue with different luminances can be mixed in one color unit, enabling application in the full-color display field.

[0132] The manufacturing method of the Micro-LED chip may include the following steps: S1. Sequentially grow an AlN buffer layer, an N-type GaN layer, a multiple quantum well active layer, and a P-type GaN layer on a sapphire substrate by means of MOCVD, MBE, PECVD, etc. to obtain an epitaxial wafer.

[0133] S2. Form an ion implantation mask for patterning by processes such as lithography. The materials of the ion implantation mask include, but are not limited to, photoresist, silicon oxide, silicon nitride, metal, etc. Using the ion implantation mask as a barrier layer, implant ions into the epitaxial structure in the epitaxial wafer to adjust the area and / or shape of the light-emitting region of the Micro-LED chip. The depth of ion implantation penetrates at least the P-type GaN layer, preferably reaching inside the N-type GaN layer. The types of implanted ions include, but are not limited to, H ions, F ions, N ions, O ions, etc. The size of the finally formed ion implantation region is 1 μm to 50 μm, and the size of the non-ion implantation region is 1 μm to 50 μm. In top view, the ion implantation region is preferably provided surrounding the non-ion implantation region, and each non-ion implantation region is used to form one LED chip structure. In this step, electrical insulation is achieved by ion implantation, which has advantages such as less loss and higher control accuracy compared with the case of performing electrical insulation by an etching process.

[0134] S3. Provide an etching mask on the ion implantation region, open a through-hole on the etching mask, the dimension of the through-hole is smaller than that of the ion implantation region, and more preferably, in order to minimize the sidewall damage of the chip, the distance between the edge of the through-hole and the edge of the ion implantation region is 100 nm to 20 μm. Further, by means of a dry etching process such as atomic layer etching (ALE), ion beam etching (IBE), inductively coupled plasma etching (ICP), etc., etch the ion implantation region through the through-hole of the etching mask, and the etching depth is smaller than or equal to the ion implantation depth, preferably smaller than the ion implantation depth, and particularly preferably reach inside the N-type GaN layer to form an insulating groove. In this step, by performing dry etching within the ion implantation region, sidewall damage caused by the etching process can be effectively avoided, not only can the photoelectric conversion efficiency be improved, but also the formed etching insulation region is narrow, and particularly, the light between each pixel in the Micro-LED chip can be effectively insulated to eliminate the optical crosstalk effect.

[0135] S4. Form a thermally conductive medium layer on the sidewall of the insulating groove by means of a process such as atomic layer deposition (ALD). In some cases, the entire inner wall of the insulating groove may be covered with the thermally conductive medium layer. Further, an opaque metal material may be deposited on the thermally conductive medium layer to form a metal light insulation layer, mainly forming a light shielding structure by the metal light insulation layer, and the optical crosstalk between each pixel point can be effectively reduced. Here, the insulating groove may be filled with the metal light insulation layer. Further, the metal light insulation layer may be continuously extended until it covers the surface of the adjacent LED chip structure to form a current spreading layer. For the current spreading layers on the surfaces of different LED chip structures, thinning treatment, patterning, etc. may be respectively performed. Then, a transparent medium layer is deposited as a passivation layer on the metal light insulation layer to passivate the surface of the metal light insulation layer and at the same time function as a heat conduction layer of the Micro-LED chip. In particular, the transparent medium layer on the surface of some LED chip structures may be patterned, and the current spreading layer on the surface of each LED chip structure may cooperate with the transparent medium layer to form the first metasurface conductive structure layer.

[0136] The above embodiments merely illustrate the principles and effects of the present application, but do not limit the present application. A person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes obtained by a person skilled in the art without departing from the spirit and technical idea disclosed in the present application shall be included in the scope of the claims of the present application.

[0137] (Supplementary Note) (Supplementary Note 1) A Micro-LED chip including an LED chip structure, wherein the Micro-LED chip further includes a first metasurface conductive structure layer, and the first metasurface conductive structure layer a first conductive layer electrically bonded on the light-emitting surface of the LED chip structure, and a metasurface structure laminated and / or integrally provided on the first conductive layer and used for modulating at least the emission angle and / or wavelength of the light emitted from the light-emitting surface. The Micro-LED chip is characterized by the above.

[0138] (Supplementary Note 2) The metasurface structure includes a first metasurface structure, the first conductive layer includes a plurality of first pattern structures, and the plurality of first pattern structures are distributed along a direction parallel to the light-emitting surface to form the first metasurface structure. The first conductive layer includes a metal conductive layer or a non-metal conductive layer. The Micro-LED chip according to Supplementary Note 1 is characterized by the above.

[0139] (Supplementary Note 3) The first conductive layer includes a metal conductive layer or a non-metal conductive layer, the thickness of the metal conductive layer is 20 nm or less, and it continuously extends along a direction parallel to the light-emitting surface. The Micro-LED chip according to Supplementary Note 1 is characterized by the above.

[0140] (Supplementary Note 4) The material of the metal conductive layer includes any one or a combination of indium, tin, silver, platinum, gold, titanium, aluminum, nickel, chromium, molybdenum, and copper, and / or the thickness of the metal conductive layer is 0.1 nm to 20 nm, or the thickness of the metal conductive layer is greater than 20 nm. and / or the material of the non-metal conductive layer includes ITO, and / or the thickness of the non-metal conductive layer is 1 nm to 500 nm, which is characterized by the Micro-LED chip according to appended claim 2 or 3.

[0141] (Appended claim 5) The first pattern structure includes an X-shaped pattern structure and a deformed Y-shaped pattern structure. In a predetermined direction parallel to the light-emitting surface, the deformed Y-shaped pattern is a shape formed by rotating the Y-shaped pattern 90° clockwise. The dimensions of both the X-shaped pattern structure and the deformed Y-shaped pattern structure are 1 nm to 1 μm. The X-shaped pattern structure and the deformed Y-shaped pattern structure are alternately arranged along the predetermined direction. Each X-shaped pattern structure and the adjacent Y-shaped pattern structure form a unit with a spacing of 1 to 500 nm. A plurality of units are periodically arranged, and the periods in both the predetermined direction and the direction perpendicular to the predetermined direction are 1 nm to 1 μm, which is characterized by the Micro-LED chip according to appended claim 2.

[0142] (Appended claim 6) The first metasurface conductive structure layer further includes a transparent medium layer laminated on the first conductive layer, which is characterized by the Micro-LED chip according to any one of appended claims 1 to 3.

[0143] (Appended claim 7) The metasurface structure includes a second metasurface structure. The transparent medium layer includes a plurality of second pattern structures. The plurality of second pattern structures are distributed along a direction parallel to the light-emitting surface to form a second metasurface structure, which is characterized by the Micro-LED chip according to appended claim 6.

[0144] (Appended claim 8) The metasurface structure is A first metasurface structure formed on the first conductive layer and used to modulate at least one of the emission angle and wavelength of the light emitted from the light emitting surface; A second metasurface structure used to modulate the other of the emission angle and wavelength of the light emitted from at least the light emitting surface, and and / or, in a direction parallel to the light emitting surface, the dimension of the second pattern structure is 1 nm to 1 μm, and / or, the second pattern structure includes a circular pattern structure with a deformed F-shaped through hole embedded in the center, in a predetermined direction parallel to the light emitting surface, the deformed F-shape is a shape formed by rotating the F-shape 30° clockwise, the dimension of the deformed F-shape is 1 to 200 nm, a plurality of the circular pattern structures are arranged periodically, and the periods in the predetermined direction and the direction perpendicular to the predetermined direction are both 1 nm to 1 μm, or, the second pattern structure includes a deformed K-shaped pattern structure and a deformed L-shaped pattern structure, in a predetermined direction parallel to the light emitting surface, the deformed K-shape is a shape formed by rotating the K-shape 45° counterclockwise, the deformed L-shape is a shape formed by mirror-inverting the L-shape, the deformed K-shaped pattern structure and the deformed L-shaped pattern structure are arranged alternately along the predetermined direction, each deformed K-shaped pattern structure and the adjacent deformed L-shaped pattern structure form a unit with a spacing of 1 to 200 nm, a plurality of the units are arranged periodically, and the periods in the predetermined direction and the direction perpendicular to the predetermined direction are both 1 to 500 nm, or, the second pattern structure includes a regular hexagonal pattern structure with an H-shaped through hole embedded in the center, the dimension of the H-shaped through hole is 1 to 200 nm, in a predetermined direction parallel to the light emitting surface, two adjacent regular hexagonal pattern structures form a unit with a spacing of 1 to 200 nm, a plurality of the units are arranged periodically, and the periods in the predetermined direction and the direction perpendicular to the predetermined direction are both 1 to 1000 nm, Alternatively, the second pattern structure includes an elliptical pattern structure. The major axis dimension of the ellipse is 1 to 1000 nm and is parallel to a predetermined direction on the light emitting surface, the minor axis dimension is 1 to 1000 nm, V-shaped through holes and X-shaped through holes are respectively formed on both sides of the minor axis, the dimensions of the V-shape and X-shape are 1 to 500 nm, the distance between the V-shaped through hole and the X-shaped through hole is 1 to 500 nm, two adjacent elliptical pattern structures form one unit with a spacing of 1 to 500 nm therebetween, a plurality of said units are arranged periodically, and the periods in the predetermined direction and in the direction perpendicular to the predetermined direction are 1 to 1000 nm. Alternatively, the second pattern structure includes a deformed z-shaped pattern structure, a deformed T-shaped pattern structure, a deformed M-shaped pattern structure, and a P-shaped pattern structure. The deformed z-shaped pattern structure and the deformed T-shaped pattern structure are alternately arranged along a predetermined direction parallel to the light emitting surface, the deformed M-shaped pattern structure and the P-shaped pattern structure are also alternately arranged along the predetermined direction, the P-shaped pattern structure and the deformed Z-shaped pattern structure are alternately arranged in the direction perpendicular to the predetermined direction, the deformed M-shaped pattern structure and the deformed T-shaped pattern structure are alternately arranged in the direction perpendicular to the predetermined direction. Each deformed Z-shaped pattern structure adjacent to a deformed T-shaped pattern structure, one deformed M-shaped pattern structure, and one P-shaped pattern structure form one unit. The distance between any two pattern structures in each said unit in the predetermined direction and in the direction perpendicular to the predetermined direction is 1 to 200 nm. A plurality of said units are arranged periodically, and the periods in the predetermined direction and in the direction perpendicular to the predetermined direction are 1 to 1000 nm. The Micro-LED chip according to appended claim 7, characterized in that.

[0145] (Appended claim 9) The material of the transparent medium layer includes any one or a combination of a plurality of silicon oxide, silicon nitride, aluminum nitride, aluminum oxide, gallium oxide, titanium oxide, and hafnium oxide, and / or the thickness of the transparent medium layer is 0.1 nm to 1 μm. The Micro-LED chip according to appended claim 6, characterized in that.

[0146] (Appendix 10) Further comprising a second metasurface conductive structure layer, wherein the LED chip structure has a first surface and a second surface opposite to the first surface, the first surface is the light emitting surface, and the second surface is electrically joined to an LED driving mechanism through a second conductive layer. The Micro-LED chip according to Appendix 1, characterized in that.

[0147] (Appendix 11) The second surface of the LED chip structure is electrically joined to an LED driving mechanism through a second metasurface conductive structure layer. The second metasurface conductive structure layer includes the second conductive layer and a third metasurface structure. The third metasurface structure is disposed on a side surface of the second conductive layer close to the LED chip structure or on the second surface of the LED chip structure, and is used to at least reflect light emitted from the LED chip structure to the second metasurface conductive structure layer. The third metasurface structure includes a plurality of third pattern structures distributed along a direction parallel to the second surface. The dimension of the third pattern structure is 1 nm to 1 μm. The third pattern structure includes an equilateral triangle pattern structure and a deformed equilateral triangle pattern structure. The equilateral triangle pattern structure and the deformed equilateral triangle pattern structure are alternately arranged along a predetermined direction parallel to the second surface. A deformed X-shaped through hole is embedded in the center of the equilateral triangle pattern structure. The deformed X shape is a shape formed by rotating the X shape clockwise by 45°. A deformed Z-shaped through hole is embedded in the center of the deformed equilateral triangle pattern structure. The deformed equilateral triangle is a shape formed by rotating an equilateral triangle clockwise by 90° around a specified point. The deformed Z shape is a shape formed by rotating the Z shape clockwise by 45°. The line segment lengths of the deformed X shape and the deformed Z shape are 1 nm to 500 nm. The midpoint of one side of each equilateral triangle pattern structure intersects with one vertex of the adjacent deformed equilateral triangle pattern structure at the specified point to form one unit. A plurality of the units are arranged periodically. The periods in the predetermined direction and the direction perpendicular to the predetermined direction are 1 nm to 1 μm. The Micro-LED chip according to Appendix 10, characterized in that.

[0148] (Appendix 12) The LED chip structure includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer laminated along a set direction. A side surface of the first doped semiconductor layer or the second doped semiconductor layer away from the active layer is the light-emitting surface, and / or the first conductive layer forms an ohmic contact with the light-emitting surface of the LED chip structure, and / or the LED chip structure includes a GaN-based LED chip structure. The Micro-LED chip according to appended claim 1 is characterized by the above.

[0149] (Appended claim 13) A method for manufacturing a Micro-LED chip according to any one of appended claims 1 to 12, manufacturing an LED chip structure, providing a first conductive layer and a metasurface structure on the light-emitting surface of the LED chip structure, wherein the metasurface structure is laminated on and / or integrally provided with the first conductive layer. The method for manufacturing a Micro-LED chip is characterized by the above.

[0150] (Appended claim 14) The metasurface structure includes a first metasurface structure. Specifically, the manufacturing method includes forming a plurality of first pattern structures in the first conductive layer when manufacturing the first conductive layer on the light-emitting surface of the LED chip structure, and distributing the plurality of first pattern structures along a direction parallel to the light-emitting surface to form the first metasurface structure. Alternatively, the metasurface structure includes a second metasurface structure. Specifically, the manufacturing method includes providing a transparent medium layer on the first conductive layer, forming a plurality of second pattern structures in the transparent medium layer, and distributing the plurality of second pattern structures along a direction parallel to the light-emitting surface to form the second metasurface structure. Alternatively, the metasurface structure includes a first metasurface structure and a second metasurface structure. Specifically, the manufacturing method when manufacturing the first conductive layer on the light-emitting surface of the LED chip structure, forming a plurality of first pattern structures in the first conductive layer, and distributing the plurality of first pattern structures along a direction parallel to the light-emitting surface to form the first metasurface structure. And, a transparent medium layer is provided on the first conductive layer, a plurality of second pattern structures are formed in the transparent medium layer, and the plurality of second pattern structures are distributed along a direction parallel to the light emitting surface to form the second metasurface structure. The method for manufacturing a Micro-LED chip according to appended claim 13, characterized in that it comprises the above.

[0151] (Appended claim 15) The method further includes electrically joining a side surface of the LED chip structure opposite to the light emitting surface to an LED driving mechanism via a second metasurface conductive structure layer. The second metasurface conductive structure layer includes a second conductive layer and a third metasurface structure. The third metasurface structure is formed on a side surface of the second conductive layer close to the LED chip structure or on a side surface of the LED chip structure opposite to the light emitting surface. The method for manufacturing a Micro-LED chip according to appended claim 13 or 14, characterized in that it comprises the above.

[0152] (Appended claim 16) A Micro-LED device comprising a Micro-LED chip according to any one of appended claims 1 to 12, characterized in that it comprises the above.

Claims

1. A Micro-LED chip including an LED chip structure, wherein the Micro-LED chip further includes a first metasurface conductive structure layer, and the first metasurface conductive structure layer includes: a first conductive layer electrically bonded on a light-emitting surface of the LED chip structure; a metasurface structure laminated and / or integrally provided on the first conductive layer and used for modulating at least an emission angle and / or a wavelength of light emitted from the light-emitting surface. The Micro-LED chip is characterized by the above.

2. The metasurface structure includes a first metasurface structure, the first conductive layer includes a plurality of first pattern structures, the plurality of first pattern structures are distributed along a direction parallel to the light-emitting surface to form the first metasurface structure, and the first conductive layer includes a metal conductive layer or a non-metal conductive layer. The Micro-LED chip according to Claim 1 is characterized by the above.

3. The first conductive layer includes a metal conductive layer or a non-metal conductive layer, the thickness of the metal conductive layer is 20 nm or less, and it continuously extends along a direction parallel to the light-emitting surface. The Micro-LED chip according to Claim 1 is characterized by the above.

4. The material of the metal conductive layer includes any one or a combination of multiple ones of indium, tin, silver, platinum, gold, titanium, aluminum, nickel, chromium, molybdenum, and copper, and / or the thickness of the metal conductive layer is 0.1 nm to 20 nm, or the thickness of the metal conductive layer is greater than 20 nm, and / or the material of the non-metal conductive layer includes ITO, and / or the thickness of the non-metal conductive layer is 1 nm to 500 nm. The Micro-LED chip according to Claim 2 or 3 is characterized by the above.

5. The first pattern structure includes an X-shaped pattern structure and a deformed Y-shaped pattern structure. In a predetermined direction parallel to the light-emitting surface, the deformed Y-shaped pattern is a shape formed by rotating the Y-shaped pattern 90° clockwise. The dimensions of both the X-shaped pattern structure and the deformed Y-shaped pattern structure are 1 nm to 1 μm. The X-shaped pattern structure and the deformed Y-shaped pattern structure are alternately arranged along the predetermined direction. Each X-shaped pattern structure and the adjacent Y-shaped pattern structure form one unit with a spacing of 1 to 500 nm. A plurality of units are arranged periodically. The periods in both the predetermined direction and the direction perpendicular to the predetermined direction are both 1 nm to 1 μm. The Micro-LED chip according to claim 2, characterized in that.

6. The first metasurface conductive structure layer further includes a transparent medium layer laminated on the first conductive layer. The Micro-LED chip according to any one of claims 1 to 3, characterized in that.

7. The metasurface structure includes a second metasurface structure. The transparent medium layer includes a plurality of second pattern structures. The plurality of second pattern structures are distributed along a direction parallel to the light-emitting surface to form a second metasurface structure. The Micro-LED chip according to claim 6, characterized in that.

8. The metasurface structure is a first metasurface structure formed on the first conductive layer and used to modulate at least one of the emission angle and wavelength of the light emitted from the light-emitting surface, and a second metasurface structure used to modulate at least the other of the emission angle and wavelength of the light emitted from the light-emitting surface, and and / or, in a direction parallel to the light-emitting surface, the dimensions of the second pattern structure are 1 nm to 1 μm, and / or, the second pattern structure includes a circular pattern structure with a deformed F-shaped through hole embedded in the center. In a predetermined direction parallel to the light-emitting surface, the deformed F-shaped pattern is a shape formed by rotating the F-shaped pattern 30° clockwise. The dimensions of the deformed F-shaped pattern are 1 to 200 nm. The plurality of circular pattern structures are arranged periodically. The periods in both the predetermined direction and the direction perpendicular to the predetermined direction are both 1 nm to 1 μm. Alternatively, the second pattern structure includes a deformed K-shaped pattern structure and a deformed L-shaped pattern structure. In a predetermined direction parallel to the light-emitting surface, the deformed K-shaped pattern is a shape formed by rotating the K-shaped pattern counterclockwise by 45°, and the deformed L-shaped pattern is a shape formed by mirror-inverting the L-shaped pattern. The deformed K-shaped pattern structure and the deformed L-shaped pattern structure are alternately arranged along the predetermined direction. Each deformed K-shaped pattern structure and the adjacent deformed L-shaped pattern structure form a unit with a spacing of 1 to 200 nm, and a plurality of the units are arranged periodically. The periods in the predetermined direction and the direction perpendicular to the predetermined direction are both 1 to 500 nm. Alternatively, the second pattern structure includes a regular hexagonal pattern structure with an H-shaped through-hole embedded in the center. The size of the H-shaped through-hole is 1 to 200 nm. In a predetermined direction parallel to the light-emitting surface, two adjacent regular hexagonal pattern structures form a unit with a spacing of 1 to 200 nm, and a plurality of the units are arranged periodically. The periods in the predetermined direction and the direction perpendicular to the predetermined direction are both 1 to 1000 nm. Alternatively, the second pattern structure includes an elliptical pattern structure. The major axis dimension of the ellipse is 1 to 1000 nm and is parallel to a predetermined direction on the light-emitting surface, and the minor axis dimension is 1 to 1000 nm. A V-shaped through-hole and an X-shaped through-hole are respectively formed on both sides of the minor axis. The dimensions of the V-shaped and X-shaped patterns are 1 to 500 nm, and the spacing between the V-shaped through-hole and the X-shaped through-hole is 1 to 500 nm. Two adjacent elliptical pattern structures form a unit with a spacing of 1 to 500 nm, and a plurality of the units are arranged periodically. The periods in the predetermined direction and the direction perpendicular to the predetermined direction are 1 to 1000 nm. Alternatively, the second pattern structure includes a deformed zigzag pattern structure, a deformed T-shaped pattern structure, a deformed M-shaped pattern structure, and a P-shaped pattern structure. The deformed zigzag pattern structure and the deformed T-shaped pattern structure are alternately arranged along a predetermined direction parallel to the light-emitting surface. The deformed M-shaped pattern structure and the P-shaped pattern structure are also alternately arranged along the predetermined direction. The P-shaped pattern structure and the deformed Z-shaped pattern structure are alternately arranged in a direction perpendicular to the predetermined direction. The deformed M-shaped pattern structure and the deformed T-shaped pattern structure are alternately arranged in a direction perpendicular to the predetermined direction. Each deformed Z-shaped pattern structure adjacent to a deformed T-shaped pattern structure, one deformed M-shaped pattern structure, and one P-shaped pattern structure form one unit. The distance between any two pattern structures in each unit in the predetermined direction and the direction perpendicular to the predetermined direction is 1 to 200 nm. A plurality of the units are periodically arranged, and the period in the predetermined direction and the direction perpendicular to the predetermined direction is 1 to 1000 nm. The Micro-LED chip according to claim 7, characterized in that.

9. The material of the transparent medium layer includes any one or a combination of silicon oxide, silicon nitride, aluminum nitride, aluminum oxide, gallium oxide, titanium oxide, hafnium oxide, and / or the thickness of the transparent medium layer is 0.1 nm to 1 μm. The Micro-LED chip according to claim 6, characterized in that.

10. Further including a second metasurface conductive structure layer, the LED chip structure has a first surface and a second surface opposite to the first surface. The first surface is the light-emitting surface, and the second surface is electrically joined to the LED driving mechanism through a second conductive layer. The Micro-LED chip according to claim 1, characterized in that.

11. The second surface of the LED chip structure is electrically joined to the LED driving mechanism through a second metasurface conductive structure layer. The second metasurface conductive structure layer includes the second conductive layer and a third metasurface structure. The third metasurface structure is disposed on a side surface of the second conductive layer close to the LED chip structure or on the second surface of the LED chip structure, and is used to at least reflect the light emitted from the LED chip structure to the second metasurface conductive structure layer. The third metasurface structure includes a plurality of third pattern structures distributed along a direction parallel to the second surface. The dimension of the third pattern structure is 1 nm to 1 μm. The third pattern structure includes an equilateral triangle pattern structure and a deformed equilateral triangle pattern structure. The equilateral triangle pattern structure and the deformed equilateral triangle pattern structure are alternately arranged along a predetermined direction parallel to the second surface. A deformed X-shaped through hole is embedded in the center of the equilateral triangle pattern structure. The deformed X shape is a shape formed by rotating the X shape 45° clockwise. A deformed Z-shaped through hole is embedded in the center of the deformed equilateral triangle pattern structure. The deformed equilateral triangle is a shape formed by rotating an equilateral triangle 90° clockwise around a specified point. The deformed Z shape is a shape formed by rotating the Z shape 45° clockwise. The line segment lengths of the deformed X shape and the deformed Z shape are 1 nm to 500 nm. The midpoint of one side of each equilateral triangle pattern structure intersects with one vertex of the adjacent deformed equilateral triangle pattern structure at the specified point to form one unit. A plurality of the units are periodically arranged. The periods in the predetermined direction and the direction perpendicular to the predetermined direction are 1 nm to 1 μm. The Micro-LED chip according to claim 10, characterized in that.

12. The LED chip structure includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer laminated along a set direction. The side surface of the first doped semiconductor layer or the second doped semiconductor layer away from the active layer is the light emitting surface, and / or the first conductive layer forms an ohmic contact with the light emitting surface of the LED chip structure, and / or the LED chip structure includes a GaN-based LED chip structure. The Micro-LED chip according to claim 1, characterized in that.

13. A method for manufacturing a Micro-LED chip according to any one of claims 1 to 12, Manufacturing an LED chip structure, Providing a first conductive layer and a metasurface structure on the light emitting surface of the LED chip structure, wherein the metasurface structure is laminated on and / or integrally provided with the first conductive layer. A method for manufacturing a Micro-LED chip, characterized by including.

14. The above-mentioned metasurface structure includes a first metasurface structure. Specifically, when fabricating a first conductive layer on the light-emitting surface of the LED chip structure, a plurality of first pattern structures are formed in the first conductive layer, and the plurality of first pattern structures are distributed along a direction parallel to the light-emitting surface to form the first metasurface structure. Alternatively, the metasurface structure includes a second metasurface structure. Specifically, the fabrication method includes providing a transparent medium layer on the first conductive layer, forming a plurality of second pattern structures in the transparent medium layer, and distributing the plurality of second pattern structures along a direction parallel to the light-emitting surface to form the second metasurface structure. Alternatively, the metasurface structure includes a first metasurface structure and a second metasurface structure. Specifically, the fabrication method is as follows: When fabricating a first conductive layer on the light-emitting surface of the LED chip structure, a plurality of first pattern structures are formed in the first conductive layer, and the plurality of first pattern structures are distributed along a direction parallel to the light-emitting surface to form the first metasurface structure. And, providing a transparent medium layer on the first conductive layer, forming a plurality of second pattern structures in the transparent medium layer, and distributing the plurality of second pattern structures along a direction parallel to the light-emitting surface to form the second metasurface structure. The fabrication method of the Micro-LED chip according to claim 13 is characterized by the above.

15. The method further includes electrically bonding the side surface of the LED chip structure opposite to the light-emitting surface to an LED driving mechanism through a second metasurface conductive structure layer. The second metasurface conductive structure layer includes a second conductive layer and a third metasurface structure. The third metasurface structure is formed on the side surface of the second conductive layer close to the LED chip structure or on the side surface of the LED chip structure opposite to the light-emitting surface. The fabrication method of the Micro-LED chip according to claim 13 or 14 is characterized by the above.

16. A Micro-LED device comprising the Micro-LED chip according to any one of claims 1 to 12.

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