Micro LED and micro lens integrated device, preparation method, and application

Abstract

Provided are a micro-LED and micro-lens integrated device, a preparation method, and an application. The preparation method comprises: operation S1: growing an epitaxial wafer structure, wherein the epitaxial wafer structure comprises, from bottom to top, a substrate, a buffer layer, an N-type semiconductor material layer, a multi-quantum well layer, an electron blocking layer, and a P-type semiconductor material layer; operation S2: etching a portion of the epitaxial wafer structure to expose the surface of the N-type semiconductor material layer; operation S3: making a first electrode on the exposed surface of the N-type semiconductor material layer; operation S4: making a second electrode on the surface of the P-type semiconductor material layer; operation S5: preparing an insulating layer on the surface of the epitaxial wafer structure other than the first electrode and the second electrode; operation S6: depositing metal electrode pads corresponding to the first electrode and the second electrode to obtain a micro-LED structure; and operation S7: preparing a micro-lens on the back of the substrate to complete the preparation of the micro-LED and micro-lens integrated device.

Description

Technical Field

[0001] The present disclosure relates to the field of microelectronics technology, and in particular to a micro LED and micro lens integrated device, a preparation method, and applications. Background Art

[0002] The problems of the prior art are as follows: At present, due to the limitations of the collimation and light extraction rate of the light emitted from the back of the substrate, it is difficult for LED to be used as an independent device in more application fields. Generally, in order to better achieve the homogenization and focusing of the LED light, it is necessary to add secondary optical devices such as lenses, reflectors, diffractors and other components on the basis of LED devices to obtain better focused light spots or more uniform and higher intensity light. There are currently two methods of adding optical elements to the LED light emission process: the first is to build an optical path and control the process of LED light propagation by designing and arranging optical elements. This method requires a large space requirement, which may be limited in some compact or space-constrained applications. At the same time, building an optical path requires complex design to reasonably arrange the placement and calibration of optical elements, which is likely to increase the manufacturing and maintenance costs of the system; the other is to attach optical elements above the chip in the LED packaging structure so that the light emitted by the overall package device can be regulated. The design complexity and installation accuracy limitations brought about by this method are also a considerable obstacle, and its energy utilization cannot be guaranteed. In addition, based on the current rapid development of optoelectronic devices, the above two methods are difficult to be well compatible with the current integrated circuit technology, and due to their size, they are limited in the high-resolution applications of future optoelectronic devices. Therefore, there is an urgent need for a new integrated device that can solve the problems of high cost, difficulty in achieving high integration and high alignment, and poor compatibility with integrated circuits and high-resolution applications. Summary of the invention

[0003] Based on the above problems, the present disclosure provides a micro LED and micro lens integrated device, a preparation method, and an application to alleviate the above technical problems in the prior art.

[0004] 1. Technical solution

[0005] One aspect of the present disclosure provides a method for preparing a micro-LED and micro-lens integrated device, including operations S1 to S7. Operation S1: growing an epitaxial wafer structure, wherein the epitaxial wafer structure includes, from bottom to top, a substrate, a buffer layer, an N-type semiconductor material layer, a multi-quantum well layer, an electron blocking layer, and a P-type semiconductor material layer; operation S2: etching a portion of the epitaxial wafer structure to expose the surface of the N-type semiconductor material layer; operation S3: making a first electrode on the surface of the exposed N-type semiconductor material layer; operation S4: making a second electrode on the surface of the P-type semiconductor material layer; operation S5: preparing an insulating layer on the surface of the epitaxial wafer structure other than the first electrode and the second electrode; operation S6: depositing metal electrode pads corresponding to the first electrode and the second electrode to obtain a micro-LED structure; and operation S7: preparing a microlens on the back of the substrate to complete the preparation of the micro-LED and micro-lens integrated device.

[0006] According to an embodiment of the present disclosure, operation S7 includes: preparing a high refractive index material layer by deposition on the back side of the substrate; and etching a portion of the high refractive index material layer to obtain a microlens that can achieve a focusing effect.

[0007] According to the embodiments of the present disclosure, the substrate is prepared from a material selected from sapphire, Si, SiC, AlN, GaN or quartz glass, and the thickness can be thinned or thickened as required; the insulating layer is prepared from a material selected from at least one of silicon oxide, silicon nitride, aluminum nitride, scandium nitride, gallium oxide, or aluminum oxide; the high refractive index material layer is prepared from a material selected from any one of silicon oxide, zinc oxide, magnesium oxide, gallium oxide, silicon nitride, aluminum nitride or scandium nitride; the epitaxial wafer is in the shape of a polygon; the micro LED is in the shape of any one of a triangle, a quadrilateral, a pentagon, a hexagon, an octagon, and a circle, and the size of the micro LED is 10nm 2 ~ 1 mm 2 .

[0008] According to the embodiment of the present disclosure, the preparation material of the N-type semiconductor material layer and the P-type semiconductor material layer is selected from Al x Ga y In 1-x-y N, or Al x Ga y In 1-x-y As, or Al x Ga y In 1-x-y P, 0≤x≤1, 0≤y≤1.

[0009] According to an embodiment of the present disclosure, the material for preparing the first electrode is selected from at least one of Ni, Cr, Ti, Al or Au; the material for preparing the second electrode is selected from at least one of Ni, Cr, Ti, Au, or ITO conductive layer; the material for preparing the electrode pad is selected from at least one of Ni, Cr, Ti, or Au.

[0010] According to an embodiment of the present disclosure, the thickness of the buffer layer 2 is 10-5000 nm; the thickness of the N-type semiconductor material layer 3 is 1000-2000 nm; the thickness of the multi-quantum well layer 4 is 50-100 nm; the thickness of the electron blocking layer 5 is 50-100 nm; the thickness of the P-type semiconductor material layer 6 is 100-500 nm; the thickness of the insulating layer 9 is 100-600nm; the size of the integrated device is 10 nm-5000 μm; the thickness of the high refractive index material layer 11 is 5-5000 nm.

[0011] Another aspect of the present disclosure provides a micro-LED and micro-lens integrated device, which is prepared by any of the preparation methods described above, and the integrated device includes: an epitaxial wafer structure, which includes, from bottom to top, a substrate, a buffer layer, an N-type semiconductor material layer, a multi-quantum well layer, an electron blocking layer and a P-type semiconductor material layer; a portion of the epitaxial wafer structure is etched to expose the surface of the N-type semiconductor material layer; a first electrode, prepared on the exposed surface of the N-type semiconductor material layer; a second electrode, prepared on the surface of the P-type semiconductor material layer; an insulating layer, prepared on the surface of the epitaxial wafer structure other than the first electrode and the second electrode; a metal electrode pad, correspondingly prepared on the first electrode and the second electrode; and a microlens, prepared on the back side of the substrate based on a high refractive index material, including a plurality of concentric circular ring grating structures.

[0012] Another aspect of the present disclosure provides an application of a light-emitting array composed of the above-mentioned micro-LED and micro-lens integrated device in maskless lithography.

[0013] Another aspect of the present disclosure provides an application of a light emitting array composed of a micro-LED and micro-lens integrated device as described above in single-pixel imaging.

[0014] Another aspect of the present disclosure provides an application of a light emitting array composed of the above-mentioned micro-LED and micro-lens integrated device in providing a patterned 220-280nm ultraviolet light source.

[0015] (II) Beneficial effects

[0016] It can be seen from the above technical solutions that the disclosed micro-LED and micro-lens integrated device, preparation method, and application have at least one or part of the following beneficial effects:

[0017] (1) It overcomes the defect that traditional LEDs can only adjust the output light by building external optical components. The purpose of output light regulation can be achieved by reasonably designing the parameters of the micro-lens;

[0018] (2) The preparation method is simple and the integration is good. In the actual system, it can be operated on a single device, thus avoiding the problems of complex optical component construction and large device size, and can improve the integration and efficiency of the system;

[0019] (3) Since there is no need to design a special epitaxial wafer structure, the defects of complex process, poor repeatability and high cost are overcome. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention is a flow chart of a method for preparing a micro-LED and micro-lens integrated device according to an embodiment of the present invention.

[0021] Figure 2 Schematic diagram of the cross-sectional structure of the micro LED and micro lens integrated device according to the embodiment of the present disclosure.

[0022] Figure 3 Schematic diagram of the bottom structure of the micro LED and micro lens integrated device according to the embodiment of the present disclosure.

[0023] Figure 4 It is a simulation diagram comparing the light fields of the bottom light-emitting cross sections of a micro-LED without a bottom micro-lens and the integrated device disclosed in the present invention.

[0024] Figure 5 Schematic diagram of the application of a micro-LED and micro-lens integrated device in a maskless lithography system according to an embodiment of the present disclosure.

[0025] Figure 6 It is a schematic diagram of the application effect of the micro-LED and micro-lens integrated device in the maskless lithography system according to the embodiment of the present disclosure.

[0026] Figure 7 Schematic diagram of the application of a micro-LED and micro-lens integrated device in single-pixel imaging according to an embodiment of the present disclosure.

[0027] Figure 8 The present invention is a schematic diagram of an application of a micro-LED and micro-lens integrated device in providing a graphic ultraviolet light source according to an embodiment of the present invention.

[0028] [Description of the main component symbols of the embodiment of the present disclosure in the accompanying drawings]

[0029] 1: substrate; 2: buffer layer; 3: N-type semiconductor material layer; 4: multi-quantum well layer; 5: electron blocking layer; 6: P-type semiconductor material layer; 7: first electrode; 8: second electrode; 9: insulating layer; 10: electrode pad; 11: high refractive index material layer. DETAILED DESCRIPTION

[0030] The present disclosure provides a micro-LED and micro-lens integrated device, preparation method, and application. The integrated chip is constructed by integrating the Micro-LED (micro light-emitting diode) on the front of the sapphire substrate and the Micro-lens (micro lens) on the back of the substrate. Micro-LED is a light-emitting device with a size less than 100 microns. By applying a forward voltage, electrons and holes are driven to radiate and recombine in the active area to release energy and emit light. Among them, regarding the microlens, a concentric circular grating of a specific size is designed on the back of the sapphire and used as a focusing optical element. Specifically, a DC voltage is applied to the P-type electrode of the Micro-LED on the front to make it work normally. The emitted ultraviolet light is emitted from the bottom of the sapphire substrate, and passes through the micro-lens integrated on the back when emitting. The micro-lens converges the emitted ultraviolet light. Based on the above principles, the light emitted by the Micro-LED can be emitted at a higher resolution (>600ppi) at the micro and nano scales. Based on this highly integrated new light-emitting device array, this patent further develops multiple new application systems. 1. The present invention can replace the light source in traditional contact lithography, thereby achieving the purpose of maskless lithography. 2. The present invention can replace the high-cost light source in the traditional single-pixel imaging system, such as the laser and DMD (digital micromirror) system, and use the FPGA control device array to realize the emission of different Hadamard images, which can greatly reduce the difficulty of operation and system cost. 3. The present invention can be used as a graphical 220-280nm ultraviolet light source, for example, to replace the traditional large-area medical ultraviolet lamp, and the shape of the light-emitting pattern can be adjusted according to the shape of the disinfection area to avoid ultraviolet light overflowing outside the area to be disinfected. Therefore, the integrated device of micro-LED and micro-lens proposed in the present invention greatly improves the integration, compatibility and cost advantages of optoelectronic devices, and provides a better solution for many high-resolution applications.

[0031] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0032] In an embodiment of the present disclosure, a method for preparing a micro LED and micro lens integrated device is provided, Figure 1-Figure 3 As shown, the preparation method includes operation S1-operation S7:

[0033] Operation S1: growing an epitaxial wafer structure, wherein the epitaxial wafer structure includes, from bottom to top, a substrate 1, a buffer layer 2, an N-type semiconductor material layer 3, a multi-quantum well layer 4, an electron blocking layer 5 and a P-type semiconductor material layer 6;

[0034] Operation S2: etching a portion of the epitaxial wafer structure to expose the surface of the N-type semiconductor material layer 3;

[0035] Operation S3: forming a first electrode 7 on the exposed surface of the N-type semiconductor material layer 3;

[0036] Operation S4: forming a second electrode 8 on the surface of the P-type semiconductor material layer 6;

[0037] Operation S5: preparing an insulating layer 9 on the surface of the epitaxial wafer structure other than the first electrode 7 and the second electrode 8;

[0038] Operation S6: depositing a metal electrode pad 10 on the first electrode 7 and the second electrode 8 to obtain a micro LED structure; and

[0039] Operation S7: preparing a micro lens on the back side of the substrate 1 to complete the preparation of the micro LED and micro lens integrated device.

[0040] According to an embodiment of the present disclosure, operation S7 includes: preparing a high refractive index material layer 11 by deposition on the back side of the substrate 1; and etching a portion of the high refractive index material layer 11 to obtain a microlens with a focusing effect, wherein the microlens may be, for example, a plurality of concentric circular ring grating structures, and the concentric circular ring spacing of the concentric circular ring grating structure is 10nm~5000um. It should be noted that the concentric circular ring grating structure is only exemplified as a preferred embodiment, and the microlens can also be realized by other structures, such as a plurality of concentric rectangular ring grating structures, or elliptical ring grating structures and other structures that can achieve a focusing effect, and the present disclosure is not limited thereto. In high-resolution display applications, a monolithic integrated chip with a Micro-LED light-emitting focusing effect can be directly realized by integrating a micro lens.

[0041] According to the embodiment of the present disclosure, the shape of the epitaxial wafer structure is polygonal; the preparation material of the substrate 1 is selected from sapphire, Si, SiC, AlN, GaN or quartz glass, and the thickness can be thinned or thickened according to needs.

[0042] According to an embodiment of the present disclosure, the size of the integrated device is 10 nm-5000 μm;

[0043] According to an embodiment of the present disclosure, the insulating layer 9 is made of at least one material selected from silicon oxide, silicon nitride, aluminum nitride, scandium nitride, gallium oxide, or aluminum oxide.

[0044] According to the embodiment of the present disclosure, the material of the high refractive index material layer 11 is selected from any one of silicon oxide, zinc oxide, magnesium oxide, gallium oxide, silicon nitride, aluminum nitride or scandium nitride. The refractive index of the high refractive index material layer 11 can reach 1.75.

[0045] According to the embodiment of the present disclosure, the preparation material of the N-type semiconductor material layer 3 and the P-type semiconductor material layer 6 is selected from Al x Ga y In 1-x-y N, or Al x Ga y In 1-x-y As, or Al x Ga y In 1-x-y P, 0≤x≤1, 0≤y≤1. The N-type semiconductor material layer 3 serves as an N-type electron injection layer, and the P-type semiconductor material layer 6 serves as a P-type hole injection layer.

[0046] According to the embodiment of the present disclosure, the material of the first electrode 7 (N-type electrode) is selected from at least one of Ni, Cr, Ti, Al or Au;

[0047] According to an embodiment of the present disclosure, the second electrode 8 (P-type electrode) is made of at least one material selected from Ni, Cr, Ti, Au, or ITO conductive layer.

[0048] According to an embodiment of the present disclosure, the electrode pad 10 is made of at least one material selected from Ni, Cr, Ti, or Au.

[0049] In operation S1, conventional epitaxial equipment used for growing epitaxial wafer structure includes MOCVD, i.e. metal organic chemical vapor deposition equipment, or MBE, i.e. molecular beam epitaxy equipment, on substrate 1, including conventional epitaxial substrates such as sapphire, Si, SiC, AlN, GaN, quartz glass, etc., a buffer layer 2 with a thickness of 10-5000 nm is epitaxially grown once, and then an N-type semiconductor material layer 3 with a thickness of 1000-2000 nm, a multi-quantum well layer 4 with a thickness of 50-100 nm, an electron blocking layer 5 with a thickness of 50-100 nm, and a P-type semiconductor material layer 6 with a thickness of 100-500 nm are epitaxially grown once on the buffer layer 2. The preparation material of the N-type semiconductor material layer 3 and the P-type semiconductor material layer 6 can be Al x Ga y In 1-x-y N, 0≤x≤1, 0≤y≤1, for example, it can be GaN, AlN, InN, or a ternary alloy material or a quaternary alloy material, or Al x Ga y In 1-x-yAs, 0≤x≤1, 0≤y≤1, for example, GaAs, AlAs, InAs, or a ternary alloy material or a quaternary alloy material, or Al x Ga y In 1-x-y P, 0≤x≤1, 0≤y≤1, for example, may be GaP, AlP, InP, or a ternary alloy material or a quaternary alloy material.

[0050] In operation S2, the P-type semiconductor material layer 6, the electron blocking layer 5, the multi-quantum well layer 4 and a portion of the N-type semiconductor material layer 3 are etched on the obtained epitaxial wafer structure by photolithography and dry etching processes, so that the surface of the N-type semiconductor material layer 3 is exposed.

[0051] In operation S3, a first electrode 7 is formed on the exposed surface of the N-type semiconductor by photolithography, evaporation, and annealing processes. For example, the first electrode 7 is Ti / Al / Ti / Au polymetal, Ti / Au polymetal, Ti / Al / Ni / Au polymetal, Cr / Au polymetal, or Cr / Al / Ti / Au polymetal.

[0052] In operation S4, a second electrode 8 is fabricated on the surface of the P-type semiconductor 5 by photolithography, evaporation, and annealing processes. For example, the second electrode 8 is Ni / Au polymetallic, Ti / Au polymetallic, ITO conductive layer, or Cr / Au polymetallic.

[0053] It should be noted that the design of the two electrode layouts of the first electrode 7 and the second electrode 8 does not affect the functional use, and the changes in the electrode shape (block electrode, interdigitated electrode, etc.) and the changes in the area ratio of the three electrodes do not affect the functional realization of the device and are all within the protection range.

[0054] In operation S5, an insulating layer 9 of 100-600 nm is deposited using an oxide deposition device. For example, the insulating layer 9 may be one or any combination of silicon oxide, silicon nitride, aluminum nitride, scandium nitride, gallium oxide, and aluminum oxide. Then, the insulating layer 9 is etched by photolithography, dry etching, and wet etching processes to expose the pad windows of the first electrode 7 and the second electrode 8;

[0055] In operation S6, the electrode pad 10 is formed in the pad window of the first electrode and the second electrode by photolithography and evaporation process. For example, the electrode pad 10 can be any conductive contact layer such as Ni / Au multi-metal, Ti / Au multi-metal, Cr / Au multi-metal, etc., thereby completing the preparation of the micro-LED structure. The shape of the micro-LED is any one of a triangle, a quadrilateral, a pentagon, a hexagon, an octagon, and a circle. The size of the micro-LED is 10nm. 2 ~ 1 mm 2In operation S7, a high refractive index material layer 11 for preparing microlenses with a thickness of 5-5000 nm is deposited on the back of the substrate 1 using a deposition device. The material of the high refractive index material layer 11 for preparing microlenses can be one of silicon oxide, zinc oxide, magnesium oxide, gallium oxide, silicon nitride, aluminum nitride, and scandium nitride.

[0056] Further, the material is etched by photolithography, dry etching, and wet etching processes to etch out concentric ring grating patterns, such as Figure 3 Thus, a monolithic integrated chip is obtained, which can directly realize the focusing effect of Micro-LED light through the integrated micro lens for high-resolution display applications.

[0057] The present disclosure also provides a micro LED and micro lens integrated device, which is prepared by the above-mentioned preparation method, combined with Figure 2 , Figure 3 As shown, the integrated device includes:

[0058] An epitaxial wafer structure, wherein the epitaxial wafer structure includes, from bottom to top, a substrate 1, a buffer layer 2, an N-type semiconductor material layer 3, a multi-quantum well layer 4, an electron blocking layer 5 and a P-type semiconductor material layer 6; a portion of the epitaxial wafer structure is etched to expose the surface of the N-type semiconductor material layer 3;

[0059] A first electrode is formed on the exposed surface of the N-type semiconductor material layer 3;

[0060] A second electrode 8 is formed on the surface of the P-type semiconductor material layer 6;

[0061] An insulating layer 9 is formed on the surface of the epitaxial wafer structure outside the first electrode 7 and the second electrode 8;

[0062] A metal electrode pad 10, formed on the first electrode 7 and the second electrode 8; and

[0063] The microlens is made of a high refractive index material and is disposed on the back of the substrate 1, and includes a plurality of concentric circular grating structures.

[0064] The present invention conducts simulation test on the focusing function realization of the proposed novel micro-LED and micro-lens integrated chip.

[0065] According to the embodiment of the present disclosure, Figure 4 As shown, the conventional LED bottom light emitting cross section is as follows Figure 4 As shown on the left, due to the wide range of light emission angles, the light emitted is scattered light; after integrating the micro lens, the light emission profile at the bottom of the LED is as follows Figure 4 As shown on the right, due to the focusing effect of the microlens, a focal point is generated at a certain distance below the substrate.

[0066] According to the embodiments of the present disclosure, the specific structure of the bottom microlens can be designed and modified according to the desired type of output light so as to be used as an optical element, such as integrating a microlens array at the bottom of an LED, or integrating a single microlens at the bottom of an LED array.

[0067] According to the embodiments of the present disclosure, the present disclosure also provides the application of the above-mentioned micro-LED and micro-lens integrated device, such as Figure 5 The left side shows the principle diagram of traditional maskless lithography. Figure 5 The right side shows the schematic diagram of the maskless lithography principle after the micro-LED and micro-lens integrated device are made into an array. By controlling whether each array unit pixel emits light, the display of a special image can be realized. The light-emitting array with high-resolution imaging can be applied to maskless lithography. Due to the improvement of collimation, high-precision and low-cost maskless lithography can be achieved, and finally it can be applied in a new maskless lithography system. The maskless lithography effect is as follows Figure 6 shown.

[0068] According to the embodiments of the present disclosure, the present disclosure also provides the application of the above-mentioned micro-LED and micro-lens integrated device in single-pixel imaging, such as Figure 7 As shown, since the integrated device is small in size, it can display images with higher resolution, so it can replace Figure 7 The conventional DMD system shown in the left dashed box (DMD is a digital micro-mirror, which is composed of a high-speed digital light reflection switch array, and determines the imaging pattern and its characteristics by controlling the rotation of the micro-mirror around a fixed (yoke) and the time domain response (determining the reflection angle and stagnation time of the light)). In the application of the embodiments of the present disclosure, Figure 7 As shown in the dotted box on the right, an FPGA can be used to control the device array to emit a Hadamard image, thereby realizing the application of the light-emitting array based on the above integrated device in a new single-pixel imaging system.

[0069] According to an embodiment of the present disclosure, the present disclosure also provides an application of the above-mentioned micro-LED and micro-lens integrated device in providing a graphic 220-280nm ultraviolet light source, such as Figure 8 The left side shows the traditional UV disinfection method. Figure 8 The right side shows the disinfection method of the light array composed of the micro LED and micro lens integrated device based on the embodiment of the present disclosure. It can be seen that due to the large irradiation area of ​​the traditional ultraviolet lamp, there is a risk of overflowing outside the area when treating the target in the area to be disinfected. The light array composed of the integrated device of the present disclosure has high collimation and high resolution, and can adjust the shape of the light pattern according to the shape of the disinfection area to prevent the ultraviolet light from overflowing outside the area to be disinfected.

[0070] So far, the embodiments of the present disclosure have been described in detail in conjunction with the accompanying drawings. It should be noted that the implementation methods not shown or described in the drawings or the body of the specification are all forms known to ordinary technicians in the relevant technical field and are not described in detail. In addition, the above definitions of each element and method are not limited to the various specific structures, shapes or methods mentioned in the embodiments, and ordinary technicians in the field can simply change or replace them.

[0071] Based on the above description, those skilled in the art should have a clear understanding of the micro-LED and micro-lens integrated device, preparation method, and application disclosed in the present invention.

[0072] In summary, the present disclosure provides a micro-LED and micro-lens integrated device, preparation method, and application. Aiming at the problem that the LED output light is difficult to control, costly, and difficult to integrate, the present invention designs a Micro-LED and Micro-lens integrated device for high-resolution applications. It provides an integrated device that is economical, reliable, simple, and adaptable to a variety of applications.

[0073] It should also be noted that the above are different embodiments provided by the present disclosure. These embodiments are used to illustrate the technical content of the present disclosure, rather than to limit the scope of protection of the present disclosure. A feature of an embodiment can be applied to other embodiments through appropriate modification, replacement, combination, and separation.

[0074] It should be noted that, in this document, unless otherwise specified, “a” element is not limited to a single element, but may include one or more elements.

[0075] In addition, in this document, unless otherwise specified, ordinal numbers such as "first" and "second" are only used to distinguish multiple components with the same name, and do not indicate that there is a hierarchy, level, execution order, or process order between them. A "first" component and a "second" component may appear together in the same component, or appear in different components. The presence of a component with a larger ordinal number does not necessarily indicate the presence of another component with a smaller ordinal number.

[0076] In this document, unless otherwise specified, the so-called feature A "or" or "and / or" (and / or) feature B means that A exists alone, B exists alone, or A and B exist at the same time; the so-called feature A "and" (and) or "and" (and) or "and" (and) feature B means that A and B exist at the same time; the so-called "include", "comprise", "have" and "contain" mean including but not limited to these.

[0077] In addition, in this document, the terms "upper", "lower", "left", "right", "front", "back", or "between" are only used to describe the relative positions between multiple elements, and can be extended to include translation, rotation, or mirroring. In addition, in this document, unless otherwise specified, "an element is on another element" or similar descriptions do not necessarily mean that the element contacts the other element.

[0078] In addition, unless the steps are specifically described or must occur in sequence, the order of the above steps is not limited to the above list, and can be changed or rearranged according to the required design. And the above embodiments can be mixed and matched with each other or with other embodiments based on design and reliability considerations, that is, the technical features in different embodiments can be freely combined to form more embodiments.

[0079] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A method for preparing an integrated device of ultraviolet micro-LED and micro-lens, comprising: Operation S1: growing an epitaxial wafer structure, wherein the epitaxial wafer structure comprises, from bottom to top, a substrate (1), a buffer layer (2), an N-type semiconductor material layer (3), a multi-quantum well layer (4), an electron blocking layer (5), and a P-type semiconductor material layer (6); Operation S2: etching a portion of the epitaxial wafer structure to expose the surface of the N-type semiconductor material layer (3); Operation S3: forming a first electrode (7) on the exposed surface of the N-type semiconductor material layer (3); Operation S4: forming a second electrode (8) on the surface of the P-type semiconductor material layer (6); Operation S5: preparing an insulating layer (9) on the surface of the epitaxial wafer structure other than the first electrode (7) and the second electrode (8); Operation S6: depositing a metal electrode pad (10) on the first electrode (7) and the second electrode (8) to obtain a micro LED structure; as well as Operation S7: preparing a micro lens on the back side of the substrate (1) to complete the preparation of the micro LED and micro lens integrated device; The operation S7 comprises: depositing a high refractive index material layer (11) on the back side of the substrate (1); and etching a portion of the high refractive index material layer (11) to form a concentric ring grating pattern, so as to obtain a microlens capable of achieving a focusing effect; The high refractive index material layer (11) is made of a material selected from any one of silicon oxide, zinc oxide, magnesium oxide, gallium oxide, silicon nitride, aluminum nitride or scandium nitride, and the thickness of the high refractive index material layer (11) is 5-5000 nm; The size of micro LED is 10nm 2 ~ 1 mm 2 The emitted ultraviolet light is emitted from the bottom of the substrate, and when emitted, it is converged by the microlens on the back to form a light-emitting array, which has an emission resolution of >600ppi at the nanoscale; A microlens array is integrated at the bottom of a micro-LED, or a single microlens is integrated at the bottom of a micro-LED array. After the micro-LED and microlens integrated devices are made into an array, the display of special images is achieved by controlling whether each array unit pixel emits light separately. The light-emitting array is used as a UV light source in maskless lithography, single-pixel imaging, and to provide a graphical UV light source.

2. The method for preparing a micro-LED and micro-lens integrated device according to claim 1, wherein: The substrate is made of a material selected from sapphire, Si, SiC, AlN, GaN or quartz glass; The insulating layer (9) is made of at least one material selected from silicon oxide, silicon nitride, aluminum nitride, scandium nitride, gallium oxide, or aluminum oxide; The epitaxial wafer is in the shape of a polygon; The shape of the micro LED is any one of a triangle, a quadrilateral, a pentagon, a hexagon, an octagon, and a circle.

3. The method for preparing a micro-LED and micro-lens integrated device according to claim 1, wherein the preparation material of the N-type semiconductor material layer (3) and the P-type semiconductor material layer (6) is selected from Al x Ga y In 1-x-y N, or Al x Ga y In 1-x-y As, or Al x Ga y In 1-x-y P, 0≤x≤1, 0≤y≤1.

4. The method for preparing a micro-LED and micro-lens integrated device according to claim 1, wherein: The first electrode (7) is made of at least one material selected from Ni, Cr, Ti, Al or Au; The second electrode (8) is made of at least one material selected from Ni, Cr, Ti, Au, or ITO conductive layer; The electrode pad (10) is made of at least one material selected from Ni, Cr, Ti, or Au.

5. The method for preparing a micro-LED and micro-lens integrated device according to any one of claims 1 to 4, wherein: The thickness of the buffer layer (2) is 10-5000 nm; The thickness of the N-type semiconductor material layer (3) is 1000-2000 nm; The thickness of the multi-quantum well layer (4) is 50-100 nm; The thickness of the electron blocking layer (5) is 50-100 nm; The thickness of the P-type semiconductor material layer (6) is 100-500 nm; The thickness of the insulating layer (9) is 100-600 nm; The size of the integrated device is 10 nm-5000 μm.

6. A micro-LED and micro-lens integrated device, prepared by the preparation method according to any one of claims 1 to 5, the integrated device comprising: An epitaxial wafer structure, the epitaxial wafer structure comprising, from bottom to top, a substrate (1), a buffer layer (2), an N-type semiconductor material layer (3), a multi-quantum well layer (4), an electron blocking layer (5) and a P-type semiconductor material layer (6); a portion of the epitaxial wafer structure is etched to expose the surface of the N-type semiconductor material layer (3); A first electrode is prepared on the exposed surface of the N-type semiconductor material layer (3); A second electrode (8) is prepared on the surface of the P-type semiconductor material layer (6); An insulating layer (9) is formed on the surface of the epitaxial wafer structure outside the first electrode (7) and the second electrode (8); Metal electrode pads (10), correspondingly prepared on the first electrode (7) and the second electrode (8); as well as A microlens, prepared on the back side of the substrate (1) based on a high refractive index material, comprising a concentric ring grating structure, wherein the microlens has a focusing effect; The size of micro LED is 10nm 2 ~ 1 mm 2 , when emitted, it is converged by the back micro-lens, and after the micro-LED and micro-lens integrated device form a light-emitting array, it has an emission with a resolution of > 600ppi at the nanoscale; A microlens array is integrated at the bottom of a micro LED, or a single micro lens is integrated at the bottom of a micro LED array. After the micro LED and micro lens integrated devices are made into an array, the display of special images is achieved by controlling whether each array unit pixel emits light separately.

7. An application of a light emitting array composed of a micro-LED and micro-lens integrated device as claimed in claim 6 as an ultraviolet light source in maskless lithography.

8. An application of a light emitting array composed of a micro-LED and micro-lens integrated device as claimed in claim 6 as an ultraviolet light source in single-pixel imaging.

9. An application of a light-emitting array composed of a micro-LED and a micro-lens integrated device as claimed in claim 6 in providing a graphic 220-280nm ultraviolet light source, wherein the shape of the light-emitting pattern is adjusted according to the shape of the disinfection area to prevent ultraviolet light from overflowing into the area to be disinfected.

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