A multi-color LED array and its preparation method

Abstract

The present invention discloses a multi-color LED array and a method for preparing the same. The array comprises: a semiconductor planar template, a first type of doped semiconductor columnar structure array, and a heterostructure device layer. The method comprises: preparing the semiconductor planar template; performing a patterning process to obtain an etching mask layer; performing a partial etching process on the intentionally doped semiconductor planar layer by dry etching and removing the etching mask layer to obtain a first type of doped semiconductor columnar structure array; performing an epitaxial growth process on the first type of doped semiconductor columnar structure array by a metal organic chemical vapor deposition method to obtain a heterostructure device layer and prepare an LED array. The present invention can simplify the preparation process of a tightly distributed color LED array, avoid the massive transfer of micro LED chips, reduce preparation costs, and improve the luminous efficiency of LED devices. As a multi-color LED array and a method for preparing the same, the present invention can be widely used in the field of semiconductor optoelectronic device technology.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor optoelectronic devices, and in particular to a multi-color LED array and a preparation method thereof. Background Art

[0002] LEDs (LEDs) have been widely used in various lighting and display applications due to their high efficiency, energy saving, and environmental friendliness. Micro-LED displays are a display technology that utilizes small LEDs as pixel units. These tiny LED units can function directly as display pixels, eliminating the need for a backlight and offering extremely high electro-optical conversion efficiency and fast response times. Mass transfer is key to manufacturing color micro-LED displays. This involves transferring millions of micro-LED chips from their growth substrate to the display substrate. However, the transfer process requires ensuring precise alignment of each LED chip and transferring only the device structure, without including the native substrate. This requires extremely high technical precision and stability. This process is costly and complex. Due to the tiny size of the LEDs, transfer is extremely difficult, resulting in low yields. Furthermore, the fabrication of micro-LED chips requires etching of the monochromatic LED epitaxial wafers, which can cause etching damage on the sidewalls and reduce device performance efficiency. As LED sizes continue to shrink and pixel density increases, even higher transfer precision and stability are required. This is especially true for micro-LEDs measuring a few microns and display requirements with higher pixel densities. Existing mass transfer technologies cannot meet the manufacturing precision and performance efficiency requirements. Summary of the Invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a multi-color LED array and a preparation method thereof, which can simplify the preparation process of tightly distributed color LED arrays, avoid the massive transfer of micro LED chips, reduce preparation costs, and improve the luminous efficiency of LED devices.

[0004] The first technical solution adopted by the present invention is: a multi-color LED array, including a semiconductor planar template, a first type of doped semiconductor columnar structure array and a heterostructure device layer, wherein the heterostructure device layer is a columnar structure array, the first type of doped semiconductor columnar structure array is provided on the upper surface of the semiconductor planar template, and the heterostructure device layer is provided on the upper surface of the first type of doped semiconductor columnar structure array, wherein:

[0005] The semiconductor plane template is used to support the LED array;

[0006] The first type of doped semiconductor columnar structure array is periodically arranged and distributed and is used to control the luminous color of the LED array;

[0007] The heterostructure device layer includes a first type of doped semiconductor, a light-emitting active region and a second type of doped semiconductor, and is used for emitting light under an external voltage.

[0008] Furthermore, the semiconductor planar template includes a substrate, an unintentionally doped semiconductor planar layer and an intentionally doped semiconductor planar layer, the upper surface of the substrate is integrated with the unintentionally doped semiconductor planar layer, and the upper surface of the unintentionally doped semiconductor planar layer is integrated with the intentionally doped semiconductor planar layer, wherein:

[0009] The substrate is used to support the unintentionally doped semiconductor planar layer and the intentionally doped semiconductor planar layer;

[0010] The non-intentionally doped semiconductor planar layer is used to isolate the substrate from the intentionally doped semiconductor planar layer;

[0011] The intentionally doped semiconductor planar layer is used to provide semiconductor material structure and conduct current.

[0012] Furthermore, the first type of doped semiconductor columnar structure array and the heterostructure device layer constitute an LED device structure, wherein the LED device structure includes a first LED device structure, a second LED device structure, and a third LED device structure. The first LED device structure, the second LED device structure, and the third LED device structure are all horizontally and closely arranged on the upper surface of the semiconductor plane template. The horizontal spacing between the first LED device structure, the second LED device structure, and the third LED device structure is 0.1-50 μm, wherein:

[0013] The first LED device structure is configured to emit light of a first color;

[0014] The second LED device structure is used to emit light of a second color;

[0015] The third LED device structure is used to emit light of a third color.

[0016] Furthermore, the heterostructure device layer includes a first type of doped semiconductor, a light emitting active region, and a second type of doped semiconductor, the light emitting active region is integrated on the upper surface of the first type of doped semiconductor, the second type of doped semiconductor is integrated on the upper surface of the light emitting active region, the first type of doped semiconductor and the second type of doped semiconductor have opposite doping types, one of which is n-type doped and the other is p-type doped, wherein:

[0017] The first type of doped semiconductor is used to conduct current under an applied voltage using electrons or holes as carriers;

[0018] The light-emitting active region is used to allow electrons and holes to undergo radiation recombination and emit light;

[0019] The second type of doped semiconductor is used to conduct current under an applied voltage using holes or electrons as carriers.

[0020] Furthermore, the light-emitting active region includes several layers of quantum confinement structures, several layers of potential barriers, and an electron blocking layer. The potential barriers are integrated on both the upper and lower surfaces of the quantum confinement structures, and the electron blocking layer is integrated on the uppermost surface of the several layers of potential barriers or the lowermost surface of the several layers of potential barriers.

[0021] The potential barrier is used to confine electrons and holes within the quantum confinement structure to form a radiation recombination luminescence confinement region;

[0022] The electron blocking layer is used to hinder the flow of conduction band electrons through the layer.

[0023] The second technical solution adopted by the present invention is: a method for preparing a multi-color LED array, comprising the following steps:

[0024] Prepare a preliminary semiconductor planar template;

[0025] Based on the preliminary semiconductor plane template, a patterning process is performed to obtain an etching mask layer;

[0026] Partially etching the intentionally doped semiconductor planar layer by dry etching and removing the etching mask layer to obtain a semiconductor planar template and a first type doped semiconductor columnar structure array;

[0027] Epitaxial growth is performed on the surface of a first type of doped semiconductor columnar structure array by a metal organic chemical vapor deposition method to obtain a heterostructure device layer and prepare an LED array.

[0028] Furthermore, the step of preparing a preliminary semiconductor plane template specifically includes:

[0029] obtaining a substrate;

[0030] The substrate is placed in a metal organic chemical vapor deposition reaction chamber, hydrogen is introduced, the substrate is heated and baked, and then the temperature is lowered and maintained within a preset temperature range, and hydrogen, ammonia and metal organic compound precursors are introduced to form a semiconductor nucleation layer on the substrate surface;

[0031] The substrate is heated, the temperature is raised and maintained, hydrogen, ammonia and metal organic compound precursors are introduced into the metal organic chemical vapor deposition reaction chamber, and an unintentionally doped semiconductor planar layer is epitaxially grown on the surface of the semiconductor nucleation layer. Then, doping gas is introduced to obtain an intentionally doped semiconductor planar layer, thereby preparing a preliminary semiconductor planar template.

[0032] Furthermore, the step of performing a patterning process based on the preliminary semiconductor plane template to obtain an etching mask layer specifically includes:

[0033] The upper surface of the preliminary semiconductor plane template is spin-coated with photoresist, and the spin-coated photoresist is pattern-exposed and developed by a photolithography machine to obtain an etching mask layer of the intentionally doped semiconductor plane layer.

[0034] Furthermore, the step of partially etching the planar semiconductor layer by dry etching and removing the etching mask layer to obtain the first type doped semiconductor columnar structure array specifically includes:

[0035] The substrate is placed in the chamber of an inductively coupled plasma etcher, and chlorine and argon gases are introduced to perform etching to a preset depth, wherein the preset depth is less than the thickness of the intentionally doped semiconductor planar layer, thereby obtaining a preliminary first type doped semiconductor columnar structure array;

[0036] The preliminary first type doped semiconductor columnar structure array is processed by a degumming solution heated in a water bath to remove the etching mask layer to obtain a semiconductor plane template and the first type doped semiconductor columnar structure array.

[0037] Furthermore, the step of performing epitaxial growth on the surface of the first type of doped semiconductor columnar structure array by metal organic chemical vapor deposition to obtain a heterostructure device layer and prepare the LED array specifically includes:

[0038] Heating the substrate, raising the temperature and maintaining the temperature within a preset range, introducing TMGa, doping gas, ammonia, nitrogen and hydrogen to obtain a first type doped semiconductor;

[0039] Cooling to a preset temperature range and maintaining it, introducing TEGa, TMIn, doping gas, ammonia and nitrogen to grow a light-emitting active region;

[0040] TMGa, doping gas, ammonia, nitrogen and hydrogen are introduced to epitaxially grow a second type of doped semiconductor layer on the light-emitting active area to obtain a heterostructure device layer and prepare an LED array.

[0041] The array and preparation method of the present invention have the following beneficial effects: the present invention forms LED devices of multiple colors by preparing arrays of multiple columnar structures on the same semiconductor plane template, with adjacent LED device structures closely distributed with a small pitch. By defining different sizes and pitches of columnar structures in different arrays, InGaN quantum confinement structures with different components are realized during epitaxial growth, thereby achieving monolithic integration of LED devices of multiple colors. This not only eliminates the need to transfer and bond multiple single-color LED chips to the same substrate, but also solves the problem that small-sized LED chips are difficult to integrate through mass transfer methods. At the same time, this method can avoid etching of the active area and avoid sidewall damage of quantum confinement structures such as quantum wells due to etching, thereby improving the quantum efficiency of the device. Compared with traditional preparation methods, it can simplify the preparation process of closely distributed color LED arrays, avoid mass transfer, reduce preparation costs, and improve device efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic structural diagram of a multi-color LED array of the present invention;

[0043] Figure 2 This is a schematic flow chart of the steps of a method for preparing a multi-color LED array according to the present invention;

[0044] Figure 3 It is a structural schematic diagram of a semiconductor planar template provided by a specific embodiment of the present invention;

[0045] Figure 4 1 is a schematic structural diagram of a first type of doped semiconductor columnar structure array provided by a specific embodiment of the present invention;

[0046] Figure 5 It is a schematic structural diagram of a preliminary semiconductor planar template provided by a specific embodiment of the present invention;

[0047] Figure 6 1 is a schematic structural diagram of an etching mask layer used in preparing a plurality of LED arrays provided by a specific embodiment of the present invention;

[0048] Figure 7 This is a schematic structural diagram of a first type of doped semiconductor columnar structure array used in preparing multiple LED arrays provided by a specific embodiment of the present invention;

[0049] Figure 8 is a schematic structural diagram of multiple LED arrays provided by a specific embodiment of the present invention;

[0050] Figure 9 This is the luminous spectrum of the multi-color LED array provided by the specific embodiment of the present invention.

[0051] Description of the drawings: 1. Substrate; 2. Unintentionally doped semiconductor planar layer; 3. Intentionally doped semiconductor planar layer; 4. First type doped semiconductor columnar structure array; 5. First type doped semiconductor; 6. Light-emitting active area; 7. Second type doped semiconductor; 8. Preliminary intentionally doped semiconductor planar layer of semiconductor planar template; 9. Etching mask layer; A. First LED device structure; B. Second LED device structure; C. Third LED device structure. DETAILED DESCRIPTION

[0052] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The step numbers in the following embodiments are provided for ease of description only and do not limit the order of the steps. The order of execution of the steps in the embodiments can be adaptively adjusted based on the understanding of those skilled in the art.

[0053] The spectrum or color of LED light emission depends on the composition of InGaN in the active region, which in turn depends on the supply and incorporation of In and Ga during epitaxial growth. If the sample surface has a columnar structure, then when InGaN is epitaxially grown on its upper surface, In and Ga will be transported through two pathways and ultimately grow to form InGaN on the sample surface: the first pathway is surface migration through the sidewalls to the upper surface of the columnar structure; the second pathway is direct transport to the upper surface of the columnar structure by a carrier gas. Due to the different surface migration lengths of In and Ga, columnar structure arrays of different sizes and spacing will affect the supply of In and Ga in the first pathway to varying degrees, resulting in a change in the ratio of In and Ga reaching the upper surface of the columnar structure, thereby achieving the growth of InGaN with different compositions on the surface, exhibiting different band gap widths and emission spectra.

[0054] Based on this, the present invention successfully achieves monolithic integration of multi-color LED devices by fabricating arrays of columnar structures of varying diameters on the same substrate using a common photolithography process. Each array forms an LED device, and each array has active InGaN quantum wells with different compositions due to the varying columnar structure sizes. This method, based on common photolithography and epitaxial growth processes, achieves close distribution and precise positioning of multi-color LED devices, avoiding the cumbersome preparation of multiple single-color LED chips and mass transfer processes. This method also prevents etching of the active area and sidewall damage to the quantum wells, thereby improving the device's quantum efficiency.

[0055] Reference Figure 1The present invention provides a multi-color LED array, comprising a semiconductor planar template, a first type doped semiconductor columnar structure array 4, and a heterostructure device layer, wherein the heterostructure device layer is a columnar structure array, the first type doped semiconductor columnar structure array is provided on the upper surface of the semiconductor planar template, and the heterostructure device layer is provided on the upper surface of the first type doped semiconductor columnar structure array, wherein:

[0056] It should be noted that the structure of this embodiment has closely distributed LED devices of different colors on the surface of the substrate, and the distance between adjacent LED devices is 1μm to 50μm. The LED devices of different colors are composed of columnar structure arrays of different diameters arranged at different periods. For larger distances between LED devices, LED chips of each color can be prepared first, and then picked up and transferred separately to combine into a multi-color LED array without adopting the technical solution of the present invention.

[0057] The semiconductor plane template is used to support the LED array;

[0058] It should be noted that, Figure 3 As shown, the semiconductor planar template includes a substrate 1, an unintentionally doped semiconductor planar layer 2 and an intentionally doped semiconductor planar layer 3, the upper surface of the substrate is integrated with the unintentionally doped semiconductor planar layer, and the upper surface of the unintentionally doped semiconductor planar layer is integrated with the intentionally doped semiconductor planar layer, wherein the substrate is used to support the unintentionally doped semiconductor planar layer and the intentionally doped semiconductor planar layer; the unintentionally doped semiconductor planar layer is used to isolate the substrate from the intentionally doped semiconductor planar layer; and the intentionally doped semiconductor planar layer is used to provide a semiconductor material structure and conduct current.

[0059] like Figure 4 As shown, below the first type doped semiconductor columnar structure array 4 is an intentionally doped semiconductor planar layer 3 , which is periodically arranged and distributed and is used to control the luminous color of the LED array.

[0060] The first type doped semiconductor columnar structure array and the heterostructure device layer form an LED device structure, such as Figure 8 As shown, the LED device structure includes a first LED device structure A, a second LED device structure B and a third LED device structure C. The first LED device structure, the second LED device structure and the third LED device structure are all horizontally and closely arranged on the upper surface of the semiconductor plane template, and the horizontal spacing between the first LED device structure, the second LED device structure and the third LED device structure is 0.1-50μm.

[0061] It should be noted that the first LED device structure is used to emit light of a first color; the second LED device structure is used to emit light of a second color; and the third LED device structure is used to emit light of a third color.

[0062] In this embodiment, the difference in central wavelengths of the emission spectra of LED devices of different colors is greater than 10 nm, the size of each LED device in any dimension is 0.1 μm to 50 μm, and the diameter of the columnar structure of each LED device is less than 10 μm.

[0063] The heterostructure device layer includes a first type doped semiconductor 5, a light emitting active region 6 and a second type doped semiconductor 7, and is configured to emit light under an external voltage.

[0064] Among them, it should be noted that the heterostructure device layer includes a first type of doped semiconductor, a light-emitting active area and a second type of doped semiconductor, the upper surface of the first type of doped semiconductor is integrated with the light-emitting active area, and the upper surface of the light-emitting active area is integrated with the second type of doped semiconductor, the doping types of the first type of doped semiconductor and the second type of doped semiconductor are opposite, one type is n-type doping and the other type is p-type doping, wherein the first type of doped semiconductor is used to conduct current with electrons or holes as carriers under an applied voltage; the light-emitting active area is used to generate light sources with different colors; the second type of doped semiconductor is used to conduct current with holes or electrons as carriers under an applied voltage, it should be noted that the majority carrier types in the first doping type semiconductor and the second doping type semiconductor are different, one type is electrons and the other type is holes.

[0065] In this embodiment, the LED device includes a first-type doped semiconductor, a light-emitting active region, and a second-type doped semiconductor in a direction perpendicular to the plane of the substrate. The first-type doped semiconductor and the second-type doped semiconductor have opposite doping types, one of which is n-type doped and the other is p-type doped. The first-type doped semiconductor and the second-type doped semiconductor are Group III nitride semiconductors with a Ga content of not less than 70%. The bottom of each LED array is connected to a continuous first-type doped semiconductor layer or a second-type doped semiconductor layer.

[0066] In this embodiment, the light-emitting active region includes several layers of quantum confinement structures, several layers of potential barriers and an electron blocking layer. The potential barriers are integrated on both the upper and lower surfaces of the quantum confinement structures, and the electron blocking layer is integrated on the upper surface of the topmost layer or the lower surface of the bottommost layer of several layers of the potential barriers. The potential barriers are used to confine electrons and holes within the quantum confinement structure to form a radiative recombination luminescence confinement region; the electron blocking layer is used to block the flow of conduction band electrons.

[0067] In this embodiment, the light emitting active region includes an electron blocking layer to reduce the overflow of conduction band electrons, that is, to prevent the electrons from reaching the p-type semiconductor without participating in recombination.

[0068] Reference Figure 2 A method for preparing a multi-color LED array comprises the following steps:

[0069] S1. Prepare a preliminary semiconductor plane template;

[0070] Specifically, a substrate is obtained; the substrate is placed in a metal organic chemical vapor deposition reaction chamber, hydrogen is introduced, the substrate is heated and baked, and then the temperature is reduced and maintained within a preset temperature range, and hydrogen, ammonia and a metal organic compound precursor are introduced to obtain a semiconductor nucleation layer on the surface of the substrate; the substrate is heated, the temperature is increased and maintained, hydrogen, ammonia and a metal organic compound precursor are introduced into the metal organic chemical vapor deposition reaction chamber, an unintentionally doped semiconductor planar layer is epitaxially grown on the surface of the semiconductor nucleation layer, and then a doping gas is introduced to obtain an intentionally doped semiconductor planar layer of a preliminary semiconductor planar template, as shown in FIG8 . Figure 5 shown.

[0071] S2. Performing a patterning process based on the preliminary semiconductor plane template to obtain an etching mask layer 9;

[0072] Specifically, the upper surface of the preliminary semiconductor plane template is spin-coated with photoresist, and the spin-coated photoresist is pattern-exposed and developed by a photolithography machine to obtain an etching mask layer of the intentionally doped semiconductor plane layer, such as Figure 6 shown.

[0073] In this embodiment, an epitaxial wafer having a semiconductor layer on its surface is provided, and a patterning process is used to prepare a periodically arranged pattern array on the surface of the area where each LED device is to be prepared, which serves as a mask for etching the semiconductor layer.

[0074] Furthermore, it should be noted that the patterning process of this embodiment can adopt photolithography or nanoimprinting, and the etching mask layer material can adopt photoresist, nanoimprinting glue, dielectric or metal. The distance between adjacent LED device areas in the pattern prepared by the patterning process is 0.1 micron to 50 microns. The size of each LED device in any dimension of the pattern prepared by the patterning process is 0.1 micron to 50 microns. The pattern prepared by the patterning process includes a circular or polygonal array of each LED structure arranged in a periodic manner. The required semiconductor layer is obtained by epitaxially growing a nucleation layer, an unintentionally doped Group III nitride semiconductor layer and a semiconductor layer on a substrate through a metal organic chemical vapor deposition process. The substrate material includes but is not limited to sapphire, silicon, silicon carbide, gallium oxide, lithium aluminate, lithium niobate, germanium, aluminum nitride, zinc oxide, boron nitride or lithium gallate. The first type of doped semiconductor and the second type of doped semiconductor are Group III nitride semiconductors with a Ga content of not less than 70%.

[0075] S3, partially etching the intentionally doped semiconductor planar layer by dry etching and removing the etching mask layer to obtain a semiconductor planar template and a first type doped semiconductor columnar structure array;

[0076] Specifically, the substrate is placed in the chamber of an inductively coupled plasma etcher, and chlorine and argon gases are introduced to perform a preset depth etching process to obtain a preliminary first-type doped semiconductor columnar structure array; the preliminary first-type doped semiconductor columnar structure array is treated with a degumming solution heated in a water bath to remove the etching mask layer to obtain the first-type doped semiconductor columnar structure array, such as Figure 7 shown.

[0077] In this embodiment, dry etching is used to etch the intentionally doped semiconductor planar layer to the required depth, and the portion covered by the etching mask layer forms a first type doped semiconductor columnar structure array. Then, the etching mask layer is removed to complete the preparation of the semiconductor planar template and the first type doped semiconductor columnar structure array.

[0078] S4. Epitaxial growth is performed on the surface of the first type of doped semiconductor columnar structure array by a metal organic chemical vapor deposition method to obtain a heterostructure device layer and prepare an LED array.

[0079] Specifically, the substrate is heated, the temperature is increased and maintained within a preset range, TMGa, doping gas, ammonia, nitrogen and hydrogen are introduced to obtain a first type of doped semiconductor; the temperature is lowered to a preset temperature range and maintained, TEGa, TMIn, doping gas, ammonia and nitrogen are introduced to grow a light-emitting active region; TMGa, doping gas, ammonia, nitrogen and hydrogen are introduced to epitaxially grow a second type of doped semiconductor layer on the light-emitting active region to obtain a heterostructure device layer, and an LED array is prepared, such as Figure 8 shown.

[0080] In this embodiment, metal organic chemical vapor deposition is used to grow the first type of doped semiconductor, the light emitting active region and the second type of doped semiconductor on the surface of the obtained columnar structure array template.

[0081] Furthermore, it should be noted that the light-emitting active region of this embodiment may include an electron blocking layer to reduce the overflow of conduction band electrons, that is, to reduce the electrons from reaching the p-type semiconductor without participating in the recombination. The formed light-emitting active region includes an InGaN quantum well, and the In content is different on the columnar structures of different diameters, ranging from 7% to 50%. Specific embodiment one:

[0083] A multi-color LED array structure is prepared on an n-type planar GaN template.

[0084] 1) Preparation of planar GaN template: First, prepare a sapphire substrate with a thickness of 650 μm, place the substrate in an MOCVD reaction chamber, heat the metal organic chemical vapor deposition reaction chamber to 1100 ° C, and perform high temperature treatment on the sapphire substrate in a hydrogen atmosphere for 20 minutes. Then reduce the temperature to 515 ° C, introduce ammonia into the reaction chamber for 3 minutes, and then introduce hydrogen and metal organic compound precursor TMGa to epitaxially grow a 20 nm GaN nucleation layer. Then, heat the reaction chamber to 1050 ° C, introduce hydrogen, TMGa and ammonia to epitaxially grow a 1 μm thick unintentionally doped GaN layer and a 2 μm thick n-type doped GaN layer. When growing the n-type doped GaN layer, SiH4 is introduced at the same time, and the doping concentration is 5×10 18 cm -3 , completing the preparation of the planar n-type doped GaN template, that is, obtaining a semiconductor planar template.

[0085] 2) A 700nm thick photoresist is evenly spin-coated on the surface of the obtained planar n-type doped GaN template. A pattern containing three device designs is exposed using a stepper lithography machine and developed to obtain a photoresist column array, which serves as a mask layer for etching the n-type doped GaN layer. These are the regions of the first LED device structure, the second LED device structure, and the third LED device structure, each with a size of 5.6μm × 4.4μm. The exposure pattern of the first LED device structure includes a circular array with a diameter of 900nm and a spacing of 160nm. The exposure pattern of the second LED device structure includes a circular array with a diameter of 560nm and a spacing of 130nm. The exposure pattern of the third LED device structure includes a circular array with a diameter of 320nm and a spacing of 70nm.

[0086] 3) A planar n-type doped GaN template having a patterned array of photoresist pillars on its surface was placed in the chamber of an inductively coupled plasma etcher, and the n-type GaN template was etched 600 nm using an inductively coupled plasma etching process in a chlorine and argon atmosphere. The template was then placed in a degumming solution and heated in a water bath at 80°C until the remaining photoresist pillars were removed, resulting in an array of n-type doped GaN pillars of varying diameters and spacings, with a continuous, unetched n-type doped GaN layer underneath.

[0087] 4) Placing the n-type doped GaN pillar array template with different diameters and spacings on the surface into the reaction chamber of a metal organic chemical vapor deposition system to epitaxially grow the LED structure. The growth steps are as follows:

[0088] The temperature of the reaction chamber was raised to 1020℃, and TMGa, SiH4, ammonia, nitrogen and hydrogen were introduced to grow an n-type doped GaN layer with a thickness of 100nm on the columnar structure. The concentration of n-type doping was 5×10 18 cm -3 , the shape of the columnar structure template changes to a hexagonal column.

[0089] Then, the active region, including the stress-regulating layer, quantum wells, barriers, and electron-blocking layers, begins to grow. The temperature is first lowered to 900°C, and the gases are switched to TEGa, TMIn, SiH4, ammonia, and nitrogen. An 80nm-thick InGaN / GaN superlattice structure is grown. The InGaN layer in the stress-regulating layer has an In content of no less than 5%. Ten periods of InGaN / GaN quantum wells and barriers are then grown. The InGaN layer is grown at 690°C to a thickness of 3nm. The InGaN composition in the first, second, and third LED device structures varies due to the diameter and spacing of the columnar structures. The GaN barrier layer is grown at 800°C to a thickness of 9nm. The gases are then switched to TEGa, TMAl, SiH4, ammonia, and hydrogen to grow a 20nm-thick AlGaN electron-blocking layer with an Al content of no less than 5%.

[0090] The temperature was raised to 900 °C, and the gas was switched to TMGa, bismuth magnesium, ammonia, nitrogen, and hydrogen to grow a 180 nm p-type doped GaN layer with a Mg doping concentration of 1×10 19 cm -3 , completing the epitaxial growth of three-color LED devices. Specific embodiment two:

[0092] A multi-color LED array structure is prepared on a p-type planar GaN template.

[0093] 1) Preparation of a planar GaN template: First, a 650 μm thick sapphire substrate was prepared and placed in a metal organic chemical vapor deposition reaction chamber. The metal organic chemical vapor deposition reaction chamber was heated to 1100°C and the sapphire substrate was subjected to high temperature treatment for 20 minutes in a hydrogen atmosphere. The temperature was then reduced to 515°C and ammonia was introduced into the reaction chamber for 3 minutes. TMGa was then introduced to epitaxially grow a 20 nm GaN nucleation layer. The temperature was then raised to 1050°C and hydrogen, TMGa, and ammonia were introduced to epitaxially grow a 1 μm thick unintentionally doped GaN layer and a 2 μm thick p-type doped GaN layer. Magnesium cyclopentadienyl was introduced simultaneously during the growth of the p-type doped GaN layer, with a doping concentration of 1×10 19 cm -3 , complete the preparation of planar p-type doped GaN template;

[0094] 2) A 700nm thick photoresist was evenly spin-coated on the surface of the obtained planar n-type doped GaN template. A pattern containing three device designs was exposed using a stepper lithography machine and developed to obtain a photoresist column array, which served as a mask layer for etching the p-type doped GaN layer. These patterns were the patterns of the first LED device structure, the second LED device structure, and the third LED device structure, each with a size of 5.6μm × 4.4μm. The exposure pattern of the first LED device structure included an array of circles with a diameter of 900nm and a spacing of 160nm. The exposure pattern of the second LED device structure included an array of circles with a diameter of 560nm and a spacing of 130nm. The exposure pattern of the third LED device structure included an array of circles with a diameter of 320nm and a spacing of 70nm.

[0095] 3) A planar p-type doped GaN template having a patterned array of photoresist pillars on its surface was placed in the chamber of an inductively coupled plasma etcher. The p-type GaN template was etched to a depth of 600 nm using an inductively coupled plasma etching process in a chlorine and argon atmosphere. The template was then placed in a degumming solution and heated in an 80°C water bath until the remaining photoresist pillars were removed, resulting in an array of p-type doped GaN pillars of varying diameters and spacings, with a continuous, unetched p-type doped GaN layer underneath.

[0096] 4) Placing a p-type doped GaN column array template having different diameters and spacings on the surface into a reaction chamber of a metal organic chemical vapor deposition system to epitaxially grow an LED structure. The growth steps are as follows:

[0097] The temperature of the reaction chamber was raised to 900°C, and TMGa, bismuth magnesium, ammonia, nitrogen and hydrogen were introduced to grow a p-type doped GaN layer with a thickness of 100 nm on the columnar structure. The p-type doping concentration was 1×10 19 cm -3 , the shape of the columnar structure template changes to a hexagonal column.

[0098] Then, the active region is grown, including the electron blocking layer, stress regulation layer, quantum well, and barrier. First, the gases are switched to TEGa, TMAl, ammonia, and hydrogen to grow a 20nm thick AlGaN electron blocking layer with an Al content of no less than 5%. The temperature is then lowered to 900°C, and the gases are switched to TEGa, TMIn, ammonia, and nitrogen to grow an 80nm thick InGaN / GaN superlattice structure. The InGaN layer in the stress regulation layer has an In content of no less than 5%. Ten periods of InGaN / GaN quantum wells and barriers are grown. The InGaN layer is grown at a temperature of 690°C and has a thickness of 3nm. The InGaN composition in the first, second, and third LED device structures varies due to the different diameters and spacing of the columnar structures. The GaN barrier layer is grown at a temperature of 800°C and has a thickness of 9nm.

[0099] The temperature was raised to 1020°C, and the gases were switched to TMGa, SiH4, ammonia, nitrogen, and hydrogen to grow a 180nm n-type doped GaN layer with a doping concentration of 5×10 18 cm -3 , completing the epitaxial growth of three-color LED devices.

[0100] Figure 9 The emission spectra of the multi-color LED array prepared for the first embodiment of the present invention are shown, from left to right, as the normalized spectra of the first, second, and third LED devices, respectively. The three LED devices have different In content in their active region InGaN quantum confinement structures, resulting in light of different colors.

[0101] The contents of the above method embodiments are all applicable to the present device embodiments. The functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0102] The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A multi-color LED array, characterized in that: The device comprises a semiconductor planar template, a first type of doped semiconductor columnar structure array, and a heterostructure device layer, wherein the heterostructure device layer is a columnar structure array, the first type of doped semiconductor columnar structure array is provided on the upper surface of the semiconductor planar template, and the heterostructure device layer is provided on the upper surface of the first type of doped semiconductor columnar structure array, wherein: The semiconductor plane template is used to support the LED array; The first type of doped semiconductor columnar structure array is periodically arranged and distributed and is used to control the luminous color of the LED array; The heterostructure device layer includes a first type of doped semiconductor, a light-emitting active region, and a second type of doped semiconductor, and is configured to emit light under an applied voltage. The light-emitting active region is integrated on the upper surface of the first type of doped semiconductor, and the second type of doped semiconductor is integrated on the upper surface of the light-emitting active region. The first type of doped semiconductor and the second type of doped semiconductor have opposite doping types, one of which is n-type doped and the other is p-type doped, wherein: The first type of doped semiconductor is used to conduct current under an applied voltage using electrons or holes as carriers; The light-emitting active region is used to allow electrons and holes to undergo radiation recombination and emit light; The second type of doped semiconductor is used to conduct current under an applied voltage using holes or electrons as carriers; The majority carrier types in the first doping type semiconductor and the second doping type semiconductor are different, one is electrons and the other is holes; The first type of doped semiconductor columnar structure array and the heterostructure device layer constitute an LED device structure, which includes a first LED device structure, a second LED device structure, and a third LED device structure. The first LED device structure, the second LED device structure, and the third LED device structure are all horizontally and closely arranged on the upper surface of the semiconductor plane template. The horizontal spacing between the first LED device structure, the second LED device structure, and the third LED device structure is 0.1-50 μm, wherein: The first LED device structure is configured to emit light of a first color; The second LED device structure is used to emit light of a second color; The third LED device structure is used to emit light of a third color; LED devices of different colors are composed of arrays of columnar structures of different diameters arranged in different periods. The difference in the central wavelength of the emission spectrum of LED devices of different colors is greater than 10 nm. The size of each LED device in any dimension is 0.1μm to 50μm, and the diameter of the columnar structure of each LED device is less than 10μm.

2. The multi-color LED array according to claim 1, characterized in that: The semiconductor planar template includes a substrate, an unintentionally doped semiconductor planar layer and an intentionally doped semiconductor planar layer, wherein the unintentionally doped semiconductor planar layer is integrated on the upper surface of the substrate, and the intentionally doped semiconductor planar layer is integrated on the upper surface of the unintentionally doped semiconductor planar layer, wherein: The substrate is used to support the unintentionally doped semiconductor planar layer and the intentionally doped semiconductor planar layer; The non-intentionally doped semiconductor planar layer is used to isolate the substrate from the intentionally doped semiconductor planar layer; The intentionally doped semiconductor planar layer is used to provide semiconductor material structure and conduct current.

3. The multi-color LED array according to claim 2, characterized in that: The light-emitting active region includes several layers of quantum confinement structures, several layers of potential barriers, and an electron blocking layer. The potential barriers are integrated on both the upper and lower surfaces of the quantum confinement structures. The electron blocking layer is integrated on the uppermost surface of the several layers of potential barriers or on the lowermost surface of the several layers of potential barriers. The potential barrier is used to confine electrons and holes within the quantum confinement structure to form a radiation recombination luminescence confinement region; The electron blocking layer is used to hinder the flow of conduction band electrons through the layer.

4. The method for preparing a multi-color LED array according to claim 1, wherein: The following steps are involved: Prepare a preliminary semiconductor planar template; Based on the preliminary semiconductor plane template, a patterning process is performed to obtain an etching mask layer; Partially etching the intentionally doped semiconductor planar layer by dry etching and removing the etching mask layer to obtain a semiconductor planar template and a first type doped semiconductor columnar structure array; Epitaxial growth is performed on the surface of a first type of doped semiconductor columnar structure array by a metal organic chemical vapor deposition method to obtain a heterostructure device layer and prepare an LED array.

5. The method for preparing a multi-color LED array according to claim 4, characterized in that: The step of preparing a preliminary semiconductor planar template specifically includes: obtaining a substrate; The substrate is placed in a metal organic chemical vapor deposition reaction chamber, hydrogen is introduced, the substrate is heated and baked, and then the temperature is lowered and maintained within a preset temperature range, and hydrogen, ammonia and metal organic compound precursors are introduced to form a semiconductor nucleation layer on the substrate surface; The substrate is heated, the temperature is raised and maintained, hydrogen, ammonia and metal organic compound precursors are introduced into the metal organic chemical vapor deposition reaction chamber, and an unintentionally doped semiconductor planar layer is epitaxially grown on the surface of the semiconductor nucleation layer. Then, doping gas is introduced to obtain an intentionally doped semiconductor planar layer, thereby preparing a preliminary semiconductor planar template.

6. The method for preparing a multi-color LED array according to claim 4, characterized in that: The step of performing a patterning process based on the preliminary semiconductor plane template to obtain an etching mask layer specifically includes: The upper surface of the preliminary semiconductor plane template is spin-coated with photoresist, and the spin-coated photoresist is pattern-exposed and developed by a photolithography machine to obtain an etching mask layer of the intentionally doped semiconductor plane layer.

7. The method for preparing a multi-color LED array according to claim 4, characterized in that: The step of partially etching the intentionally doped semiconductor planar layer by dry etching and removing the etching mask layer to obtain the first type doped semiconductor columnar structure array specifically includes: The substrate is placed in the chamber of an inductively coupled plasma etcher, and chlorine and argon gases are introduced to perform etching to a preset depth, wherein the preset depth is less than the thickness of the intentionally doped semiconductor planar layer, thereby obtaining a preliminary first type doped semiconductor columnar structure array; The preliminary first type doped semiconductor columnar structure array is processed by a degumming solution heated in a water bath to remove the etching mask layer to obtain a semiconductor plane template and the first type doped semiconductor columnar structure array.

8. The method for preparing a multi-color LED array according to claim 4, characterized in that: The step of performing epitaxial growth on the surface of the first type of doped semiconductor columnar structure array by metal organic chemical vapor deposition to obtain a heterostructure device layer and prepare the LED array specifically includes: Heating the substrate, raising the temperature and maintaining the temperature within a preset range, introducing TMGa, doping gas, ammonia, nitrogen and hydrogen to obtain a first type doped semiconductor; Cooling to a preset temperature range and maintaining it, introducing TEGa, TMIn, doping gas, ammonia and nitrogen to grow a light-emitting active region; TMGa, doping gas, ammonia, nitrogen and hydrogen are introduced to epitaxially grow a second type of doped semiconductor layer on the light-emitting active area to obtain a heterostructure device layer and prepare an LED array.

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