Method for growing gallium nitride single crystal array with adjustable band gap through in-situ confinement reaction

Abstract

The invention provides a method for growing a gallium nitride single crystal array with an adjustable band gap through an in-situ confinement reaction, which comprises the following steps of: attaching and pressing an asymmetric wettability micro-column template and a substrate, injecting a gallium source which is fluid from a hole in one side of the substrate, and directionally transmitting and flowing the gallium source along the top end of a micro-column under the confinement action of the micro-column template to obtain a gallium source array; heating the gallium source array in a nitrogen source atmosphere to enable the gallium source array and a nitrogen source to be subjected to an in-situ chemical reaction to obtain a gallium nitride pattern array; and after cooling and annealing, stripping the gallium nitride single crystal pattern array from the micro-column template to obtain an in-situ growth gallium nitride pattern array. The gallium source array is obtained by adjusting the proportion of gallium and indium or aluminum and the like, and the gallium nitride pattern doped with indium or aluminum and the like and adjustable in band gap grows through in-situ reaction; according to the method, the doping metal proportion can be flexibly regulated and controlled to regulate and control the crystal property, the used template can be repeatedly utilized, the cost is low, operation is convenient, materials and devices are safe and easy to obtain, and large-scale industrialization is expected to be achieved.

Description

Technical Field

[0001] The invention relates to the field of chemical technology, and in particular to a method for growing a bandgap-adjustable gallium nitride single crystal array by in-situ confined reaction. Background Art

[0002] Gallium nitride (GaN) is a direct bandgap semiconductor with a bandgap width of 3.4eV and a bulk melting point of up to 1700°C. It has excellent optoelectronic properties, thermal stability and chemical stability, and has broad application prospects in semiconductor light-emitting diodes, laser displays, visible light communications, power electronic devices, microwave radio frequencies, ultraviolet detectors, solar photovoltaic devices and other fields.

[0003] Currently, the more mature methods for preparing gallium nitride single crystals include MOCVD, HVPE, ammonothermal method and solvent method. These methods have harsh reaction conditions, high costs, complicated steps, and demanding requirements on the substrate and conditions.

[0004] In order to meet the needs of high-density integration, it is also necessary to perform micro-nano processing and patterning of GaN single crystals, but the current methods often introduce defects and cracks due to lattice mismatch and thermal mismatch, which affects its performance. Furthermore, in order to prepare high-performance optoelectronic and electronic devices, it is also crucial to change the type and ratio of doping to control the band gap of GaN. Currently, commonly used technologies include MOCVD, MBE ion implantation, magnetron sputtering, etc. These doping methods have high equipment costs, complex operations, poor uniformity when preparing large areas, and are sensitive to reaction conditions, which are not conducive to large-scale production.

[0005] Therefore, it is urgent to develop a simple, economical, efficient and high-quality bandgap-tunable GaN single crystal patterning integration method. Summary of the invention

[0006] The present invention aims to solve the problem of patterned integration of bandgap-adjustable gallium nitride single crystals, and provides a method for in-situ confined reaction growth of bandgap-adjustable gallium nitride single crystal arrays, wherein liquid metal gallium (or alloys containing metals such as indium or aluminum) or liquid-phase processable gallium salts (or mixtures of gallium salts and indium salts or aluminum salts, etc.) are used as gallium sources, and liquid metal gallium arrays are prepared on a substrate through the induction of an asymmetric wettability micro-pillar template; the gallium source and the nitrogen source are subjected to an in-situ chemical reaction by utilizing the spatial confinement effect of the micro-pillar template, and after the reaction, appropriate annealing and cooling are performed, and the in-situ grown gallium nitride single crystal pattern array is peeled off from the micro-pillar template;

[0007] The present invention provides a method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array, comprising the following steps:

[0008] S1. The asymmetric wettable micro-pillar template is pressed against the substrate, and a gallium source is injected from the hole on one side of the substrate. The gallium source is a fluid. Under the confinement of the micro-pillar template, the gallium source is transmitted and flows along the top of the micro-pillar to obtain a gallium source array;

[0009] S2, heating the gallium source array in a nitrogen source atmosphere to allow the gallium source array to undergo an in-situ chemical reaction with the nitrogen source to obtain a gallium nitride pattern array;

[0010] S3. After cooling and annealing, the gallium nitride single crystal pattern array is peeled off from the micro-pillar template to obtain an in-situ grown gallium nitride pattern array. A method for in-situ confined reaction growth of a gallium nitride single crystal array with adjustable bandgap is completed.

[0011] The method for growing a bandgap-adjustable gallium nitride single crystal array by in-situ confined reaction described in the present invention is, as a preferred embodiment, in step S1, the gallium source can be liquid metal gallium or an anhydrous gallium chloride solution, and indium or aluminum can be doped in the gallium source, and the bandgap can be adjusted by changing the ratio of the doped metal.

[0012] The method for in-situ confined reaction growth of a bandgap adjustable gallium nitride single crystal array described in the present invention is, as a preferred embodiment, in step S1, the gallium source is liquid metal gallium, and the gallium source array is a liquid metal gallium array; in an anhydrous and oxygen-free environment and under heating conditions of 50-60° C., liquid metal gallium is injected from the holes on one side of the substrate;

[0013] In step S2, the liquid metal gallium array is placed in a nitrogen atmosphere, heated to 900-1000° C., and a nitrogen source is introduced, wherein the nitrogen source is ammonia gas. The heat preservation reaction time is 120-150 minutes, and the liquid metal gallium array and the ammonia gas react in situ to obtain a gallium nitride single crystal pattern array.

[0014] In step S3, when the temperature drops to 750°C, the nitrogen source atmosphere is introduced again for annealing, and after the temperature drops to room temperature, the gallium nitride single crystal pattern array is peeled off from the substrate to obtain an in-situ grown gallium nitride single crystal pattern array.

[0015] The method for in-situ confined reaction growth of a bandgap adjustable gallium nitride single crystal array described in the present invention is, as a preferred embodiment, in step S1, the gallium source is a liquid gallium-indium alloy, and the gallium source array is a liquid gallium-indium array; in an anhydrous and oxygen-free environment and under heating conditions of 30-120° C., the liquid gallium-indium alloy is injected from the hole on one side of the substrate, and the indium content in the liquid gallium-indium alloy is 20-50%;

[0016] In step S2, while keeping the micro-pillar template and the substrate pressed tightly, the liquid metal gallium indium array is placed in a nitrogen atmosphere, heated to 850-950° C., and a nitrogen source is introduced, wherein the nitrogen source is ammonia gas. The heat preservation reaction time is 120-150 minutes, and the liquid metal gallium indium array reacts with the ammonia gas in situ to obtain an InGaN pattern array;

[0017] In step S3, when the temperature is lowered to 750°C, a nitrogen source atmosphere is introduced again for annealing, and after the temperature is lowered to room temperature, the InGaN pattern array is peeled off from the substrate to obtain an in-situ grown InGaN pattern array.

[0018] The method for in-situ confined reaction growth of a bandgap adjustable gallium nitride single crystal array described in the present invention is, as a preferred embodiment, in step S1, the gallium source is a liquid gallium aluminum alloy, and the gallium source array is a liquid gallium aluminum array; in an anhydrous and oxygen-free environment, under the condition of heating at 550-650° C., the liquid gallium aluminum alloy is injected from the hole on one side of the substrate, and the aluminum content in the liquid gallium aluminum alloy is 20-50%;

[0019] In step S2, while keeping the micro-pillar template and the substrate pressed tightly, the liquid metal gallium aluminum array is placed in a nitrogen atmosphere, heated to 950-1050° C., and a nitrogen source is introduced, wherein the nitrogen source is ammonia gas. The heat preservation reaction time is 150-180 minutes, and the liquid metal gallium aluminum array and the ammonia gas undergo an in-situ chemical reaction to obtain an AlGaN pattern array;

[0020] In step S3, when the temperature is lowered to 750°C, a nitrogen source atmosphere is introduced again for annealing, and after the temperature is lowered to room temperature, the AlGaN pattern array is peeled off from the substrate to obtain an in-situ grown AlGaN pattern array.

[0021] The method for in-situ confined reaction growth of a bandgap adjustable gallium nitride single crystal array described in the present invention is, as a preferred embodiment, in step S1, the gallium source is a 0.25-0.5 mmol / mL DMF solution of anhydrous gallium chloride, and the gallium source array is a liquid metal gallium array; in an anhydrous and oxygen-free environment, under heating conditions of 550-650° C., the gallium source is injected from the holes on one side of the substrate, and the solvent is evaporated to obtain the gallium source array, and the gallium source array is a metal halide array;

[0022] In step S2, the gallium source array is placed in a nitrogen atmosphere, heated to 900-1000° C. while the micro-pillar template and the substrate are pressed tightly together, and a nitrogen source is introduced, wherein the nitrogen source is ammonia gas, and the heat preservation reaction time is 90-120 minutes. The liquid metal gallium array and the ammonia gas react in situ to obtain a gallium nitride single crystal pattern array;

[0023] In step S3, when the temperature drops to 750°C, the nitrogen source atmosphere is introduced again for annealing, and after the temperature drops to room temperature, the gallium nitride single crystal pattern array is peeled off from the substrate to obtain an in-situ grown gallium nitride single crystal pattern array.

[0024] The method for growing a bandgap-adjustable gallium nitride single crystal array by in-situ confined reaction of the present invention is, as a preferred embodiment, in step S1, the gallium source is a DMF mixed solution of anhydrous gallium chloride and indium chloride with a concentration of 0.25-0.5 mmol / mL and a Ga:In molar ratio of 4:1-1:1, and the gallium source array is a metal halide array; in an anhydrous and oxygen-free environment, the gallium source is injected from the hole on one side of the substrate, and the solvent is evaporated to obtain the gallium source array, and the gallium source array is a metal halide array;

[0025] In step S2, the gallium source array is placed in a nitrogen atmosphere, heated to 850-950° C., and a nitrogen source is introduced, wherein the nitrogen source is ammonia gas. The heat preservation reaction time is 180-200 minutes, and the metal halide array and ammonia gas react in situ to obtain an InGaN pattern array.

[0026] In step S3, when the temperature is lowered to 750°C, a nitrogen source atmosphere is introduced again for annealing, and after the temperature is lowered to room temperature, the InGaN pattern array is peeled off from the substrate to obtain an in-situ grown InGaN pattern array.

[0027] The method for in-situ confined reaction growth of a bandgap adjustable gallium nitride single crystal array described in the present invention is, as a preferred embodiment, in step S1, the gallium source is a DMF mixed solution of anhydrous gallium chloride and aluminum chloride with a concentration of 0.25-0.5 mmol / mL and a Ga:Al molar ratio of 4:1-1:1, and the gallium source array is a metal halide array; in an anhydrous and oxygen-free environment, the gallium source is injected from the hole on one side of the substrate, and the solvent is evaporated to obtain the gallium source array, and the gallium source array is a metal halide array;

[0028] In step S2, the gallium source array is placed in a nitrogen atmosphere, heated to 1000-1100° C. while the micro-pillar template and the substrate are pressed tightly together, and a nitrogen source is introduced, wherein the nitrogen source is ammonia gas, and the heat preservation reaction time is 120-180 minutes, and the metal halide array and the ammonia gas react in situ to obtain an AlGaN pattern array;

[0029] In step S3, when the temperature is lowered to 750°C, a nitrogen source atmosphere is introduced again for annealing, and after the temperature is lowered to room temperature, the AlGaN pattern array is peeled off from the substrate to obtain an in-situ grown AlGaN pattern array.

[0030] The method for in-situ confined reaction growth of a bandgap adjustable gallium nitride single crystal array described in the present invention is, as a preferred embodiment, in step S1, the asymmetric wettability microcolumn template includes microcolumns arranged in an array, the microcolumns are modified by asymmetric infiltration to make the top hydrophilic and the sidewall hydrophobic, the interval of the microcolumns is 1-100 μm, the width is 1-100 μm, and the height is 10-100 μm. The shape of the microcolumns is a straight line, a rectangle, a triangle, or a ring, and the asymmetric wettability microcolumn template is prepared by photolithography;

[0031] The material of the microcolumn is silicon, and the substrate is any of the following: silicon wafer, sapphire, quartz wafer, silicon dioxide wafer, gold wafer, silver wafer, and platinum wafer;

[0032] In step S1, the injection amount of the gallium source is 15 μL.

[0033] The method for in-situ confined reaction growth of a bandgap adjustable gallium nitride single crystal array described in the present invention is, as a preferred mode, in step S2, the micro-pillar template is kept pressed against the substrate, the gallium source array is placed in a tubular furnace filled with a nitrogen atmosphere, the temperature is raised to a first specified temperature at a heating rate of 10°C / min, and then ammonia is introduced into the tubular furnace at a flow rate of 300-500sccm to cause an in-situ chemical reaction, and then the reaction is kept warm;

[0034] In step S3, after the in-situ chemical reaction is completed, the introduction of ammonia is stopped and nitrogen is continued, and the temperature is lowered to the second specified temperature at a rate of 5°C / min, and then ammonia with a flow rate of 300-500sccm is introduced again for annealing for 90-120min. After the annealing is completed, the introduction of ammonia is stopped and nitrogen is introduced instead, and then the temperature is lowered to room temperature at a rate of 5°C / min.

[0035] The present invention comprises the following steps:

[0036] 1) Prepare the gallium source array required for the synthesis of gallium nitride. Liquid metal gallium (doped with indium or aluminum, etc.) or liquid-phase processable gallium salt (introduced with indium salt or aluminum salt, etc.) is used as the gallium source. Under the induction of the asymmetric wettability micro-pillar template, a fluid is introduced on one side of the micro-pillar template, and the liquid metal gallium is directed to be transported at the top of the silicon pillar to prepare a liquid metal gallium array on the substrate; the gallium salt solution flows in a directed manner at the top of the silicon pillar, and the solvent evaporates to prepare the gallium salt array; or the gallium salt solution first forms a continuous liquid film between the silicon pillar template and the substrate, and is divided into independent liquid bridges under the action of Laplace pressure and capillary force, and the solvent evaporates further to prepare the gallium salt array.

[0037] 2) Using the spatial confinement effect of the micro-pillar template to make the gallium source and the nitrogen source react in situ. The gallium source array confined and patterned by the silicon pillar template, together with the silicon pillar template and the substrate, is placed in a nitrogen source and heated. The gaseous nitrogen source and the gallium source array patterned on the substrate react in situ in the confined space formed by the silicon pillar and the substrate to form a gallium nitride single crystal.

[0038] 3) After the reaction, proper annealing and cooling are performed to peel off the in-situ grown GaN single crystal pattern array from the micro-pillar template. The reaction temperature, the flow rate and concentration of the gaseous nitrogen source, and the annealing procedure are controlled to reduce defects and cracks caused by cooling. After cooling, due to the orderly microscopic morphology of the micro-pillar template, the GaN single crystal pattern array grown on the substrate and having the same shape as the micro-pillar template can be easily directly peeled off from the micro-pillar template.

[0039] The gallium source array and gallium nitride single crystal pattern prepared by the method provided by the present invention can obtain different structures by designing micro-column templates of different shapes and sizes, and the properties of the crystal can be regulated by changing the proportion of doped metals, which is expected to realize subsequent integrated applications such as photonic integrated chips, light-emitting diodes, and lasers. The method has low cost, simple steps, and relatively safe and easy-to-obtain instruments and reaction raw materials, and has prospects for industrialization.

[0040] The present invention provides a method for preparing a liquid metal gallium and a gallium salt array and growing a gallium nitride single crystal pattern by in-situ confined chemical reaction, and doping indium or aluminum into a gallium source to prepare a gallium nitride single crystal pattern with adjustable doping band gap. The present invention includes the following steps: 1) preparing a gallium source array required for synthesizing gallium nitride. Liquid metal gallium (or an alloy containing metals such as indium or aluminum) or a gallium salt that can be processed in liquid phase (or a mixture of gallium salt and indium salt or aluminum salt, etc.) is used as a gallium source, and under the induction of an asymmetric wettability micro-column template, a fluid is introduced on one side of the micro-column template, and the liquid metal is directed to be transmitted at the top of the silicon column to prepare a liquid metal gallium array on a substrate; the gallium salt solution flows in a directional manner at the top of the silicon column, and the solvent evaporates to prepare a gallium salt array; or the gallium salt solution first forms a continuous liquid film between the silicon column template and the substrate, and is divided into independent liquid bridges under the action of Laplace pressure and capillary force, and the solvent further evaporates to prepare a gallium salt array. 2) The spatial confinement effect of the micro-column template is used to cause an in-situ chemical reaction between the gallium source and the nitrogen source. The gallium source array confined and patterned by the silicon pillar template is placed in a nitrogen source together with the silicon pillar template and the substrate and heated. The gaseous nitrogen source and the gallium source array patterned on the substrate undergo an in-situ chemical reaction in the confined space formed by the silicon pillar and the substrate to form a gallium nitride single crystal. 3) After the reaction, appropriate annealing and cooling are performed to peel off the in-situ grown gallium nitride single crystal pattern array from the micro-pillar template. The temperature of the reaction, the flow rate and concentration of the gaseous nitrogen source, and the annealing procedure are controlled to reduce defects and cracks caused by cooling. Since the micro-pillar template has an ordered microscopic morphology, it is easy to directly peel off the micro-pillar template after cooling, and a gallium nitride single crystal pattern array consistent with the shape of the micro-pillar template is grown on the substrate. The method provided by the present invention has low cost, simple steps, relatively safe and easy-to-obtain instruments and equipment and reaction raw materials, has the potential for industrialization, and is expected to realize integrated applications such as photonic integrated chips, light-emitting diodes, and lasers.

[0041] The present invention has the following advantages:

[0042] (1) The present invention uses liquid metal gallium (or an alloy containing metals such as indium or aluminum) or a gallium salt that can be processed in liquid phase (or a mixture of a gallium salt and an indium salt or an aluminum salt, etc.) as a gallium source, and prepares a liquid metal gallium array on a substrate by induction of an asymmetric wettability micro-pillar template; utilizes the spatial confinement effect of the micro-pillar template to cause an in-situ chemical reaction between the gallium source and the nitrogen source, and performs appropriate annealing and cooling after the reaction, and peels off the in-situ grown gallium nitride single crystal pattern array from the micro-pillar template.

[0043] (2) A gallium source array is obtained by adjusting the ratio of metal gallium and metals such as indium or aluminum, and a bandgap-adjustable gallium nitride pattern doped with indium or aluminum is grown by in-situ reaction;

[0044] (3) The present invention is a method for growing gallium nitride single crystal patterns by in-situ confined chemical reaction, which can flexibly adjust the proportion of doped metals to adjust the crystal properties. The template used is reusable, low-cost, easy to operate, and the materials and devices are safe and easy to obtain, and it is expected to achieve large-scale industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1a A schematic diagram of gallium melt patterning preparation for a method of in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array;

[0046] Figure 1b A schematic diagram of an in-situ confinement reaction of gallium nitride, which is a method for growing a bandgap-adjustable gallium nitride single crystal array by in-situ confinement reaction;

[0047] Figure 2a An optical microscope image of a liquid metal gallium patterned array of a method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array;

[0048] Figure 2b A method for in-situ confined reaction growth of a gallium nitride single crystal array with adjustable bandgap. An optical microscope image of an in-situ confined reaction growth of a gallium nitride single crystal pattern;

[0049] Figure 3 A method for in-situ confined reaction growth of a bandgap-adjustable GaN single crystal array; scanning electron microscope images and energy spectrum data of a GaN single crystal pattern array;

[0050] Figure 4 A method for in-situ confined reaction growth of a bandgap-adjustable GaN single crystal array Raman spectrum of a GaN single crystal pattern array;

[0051] Figure 5a An optical microscope image of a gallium-indium alloy array array is a method for growing a bandgap-adjustable gallium nitride single crystal array by in-situ confined reaction;

[0052] Figure 5bA method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array; an optical microscope image of an InGaN array pattern grown by in-situ confined reaction;

[0053] Figure 6 A method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array is provided. The scanning electron microscope image and energy spectrum data of the InGaN array grown by in-situ confined reaction of liquid metal are provided;

[0054] Figure 7a An optical microscope image of a gallium-aluminum alloy array showing a method for in-situ confined reaction growth of a gallium nitride single crystal array with adjustable bandgap;

[0055] Figure 7b An optical microscope image of an AlGaN array grown by in-situ confined reaction in Example 3 of a method for growing a gallium nitride single crystal array with adjustable bandgap by in-situ confined reaction;

[0056] Figure 8 A method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array is provided, which is a scanning electron microscope image and energy spectrum data image of an AlGaN array grown by in-situ confined reaction of liquid metal;

[0057] Figure 9a This is an optical microscope image of a gallium chloride patterned array in Example 4 of a method for growing a bandgap-adjustable gallium nitride single crystal array by in-situ confined reaction;

[0058] Figure 9b An optical microscope image of a pattern of a gallium nitride single crystal grown by in-situ confined reaction in Example 4 of a method for growing a gallium nitride single crystal array with adjustable bandgap by in-situ confined reaction;

[0059] Fig.10 This is an X-ray diffraction data diagram of the gallium nitride single crystal pattern array in Example 4 of a method for growing a gallium nitride single crystal array with adjustable bandgap by in-situ confined reaction. DETAILED DESCRIPTION

[0060] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0061] Example 1

[0062] like Figure 1a-1b As shown, a method for in-situ confined reaction growth of a gallium nitride single crystal array with adjustable bandgap, preparing a liquid metal gallium array and an in-situ confined reaction growth GaN single crystal pattern, comprising the following steps:

[0063] 1) A silicon pillar template having a plurality of silicon pillar arrays is prepared by photolithography, each silicon pillar having a width of 4 μm, a spacing of 20 μm, and a height of 15 μm, and an asymmetric wettability modification treatment is performed on the silicon pillar to make the top of the silicon pillar hydrophilic and the side wall hydrophobic.

[0064] 2) In an anhydrous and oxygen-free environment and under heating conditions of 50-60°C, the top of the silicon column template is pressed against the quartz substrate, and 15 μL of liquid metal gallium is injected from the hole on one side of the quartz substrate. The liquid metal gallium is directed along the top of the column under the confinement of the silicon column template to prepare a liquid metal gallium array. The optical microscope photo is shown in FIG. Figure 2a As shown, the prepared liquid metal gallium melt patterned array has neat edges, uniform morphology, and is highly ordered.

[0065] 3) Keeping the silicon pillar template and the substrate pressed tightly, place the gallium source array in a tubular furnace filled with nitrogen atmosphere, heat it to 1000°C at a heating rate of 10°C / min, introduce gaseous nitrogen source ammonia at a flow rate of 500sccm into the tubular furnace, and keep the reaction for 120 minutes. Under the confinement effect of the silicon pillar template, the gallium source pattern on the substrate reacts in situ with the continuously introduced ammonia to grow GaN single crystals.

[0066] 4) After the reaction is completed, stop introducing ammonia, continue introducing nitrogen, cool down to 750°C at a rate of 5°C / min, introduce ammonia at a flow rate of 500 sccm again for annealing for 120 min, stop introducing ammonia and replace with nitrogen, cool down to room temperature at a rate of 5°C / min, and peel off the template to prepare a GaN single crystal pattern, such as Figure 2b As shown, the array edge of the in-situ confined reaction-grown GaN single crystal pattern is neat, the morphology is uniform, and it is highly ordered;

[0067] like Figure 3 As shown, scanning electron microscope photos show that the GaN single crystal array has uniform morphology, high order, and accurate position, and the energy spectrum data shows that the elements are evenly distributed;

[0068] like Figure 4 Shown is the Raman spectrum of a GaN single crystal pattern array.

[0069] Example 2

[0070] like Figure 1a-1b As shown, a method for in-situ confined reaction growth of a bandgap adjustable gallium nitride single crystal array, preparing a liquid metal indium gallium array and in-situ confined reaction growth of an InGaN pattern, comprises the following steps:

[0071] 1) A silicon pillar template having a plurality of silicon pillar arrays is prepared by photolithography, each silicon pillar having a width of 4 μm, a spacing of 20 μm, and a height of 15 μm, and an asymmetric wettability modification treatment is performed on the silicon pillar to make the top of the silicon pillar hydrophilic and the side wall hydrophobic.

[0072] 2) In an anhydrous and oxygen-free environment and under heating conditions of 30-120°C, the top of the silicon column template is pressed tightly against the quartz substrate, and 15 μL of liquid gallium-indium alloy with an indium content of 50% is injected from the hole on one side of the quartz substrate. The liquid metal is directionally transmitted along the top of the column under the confinement effect of the silicon column template to prepare a liquid metal array.

[0073] 3) Keeping the silicon pillar template and the substrate tightly pressed, the liquid metal array is placed in a tubular furnace filled with nitrogen atmosphere, and the temperature is raised to 950°C at a heating rate of 10°C / min. Ammonia gas, a nitrogen source, is introduced into the tubular furnace at a flow rate of 500sccm, and the reaction is kept at this temperature for 150min. Under the confinement of the silicon pillar template, the liquid metal pattern on the substrate reacts in situ with the continuously introduced ammonia gas to grow an InGaN pattern, such as Figure 5a shown.

[0074] 4) After the reaction is completed, stop introducing ammonia, continue introducing nitrogen, cool down to 750°C at a rate of 5°C / min, introduce ammonia at a flow rate of 500 sccm again for annealing for 120 min, stop introducing ammonia and replace with nitrogen, cool down to room temperature at a rate of 5°C / min, and peel off the template to prepare an InGaN pattern array, such as Figure 5b shown.

[0075] like Figure 6 As shown, the prepared gallium-indium alloy array and the grown InGaN array have neat edges, uniform morphology, and are highly ordered.

[0076] Example 3

[0077] like Figure 1a-1b As shown, a method for in-situ confined reaction growth of a gallium nitride single crystal array with adjustable bandgap, preparing a liquid metal aluminum gallium array and an in-situ confined reaction growth AlGaN pattern, comprises the following steps:

[0078] 1) A silicon pillar template having a plurality of silicon pillar arrays is prepared by photolithography, each silicon pillar having a width of 4 μm, a spacing of 20 μm, and a height of 15 μm, and an asymmetric wettability modification treatment is performed on the silicon pillar to make the top of the silicon pillar hydrophilic and the side wall hydrophobic.

[0079] 2) In an anhydrous and oxygen-free environment and under heating conditions of 550-650°C, the top of the silicon column template is pressed tightly against the quartz substrate, and 15 μL of liquid gallium-aluminum alloy with an aluminum content of 50% is injected from the hole on one side of the quartz substrate. The liquid metal is directionally transmitted along the top of the column under the confinement effect of the silicon column template to prepare a liquid metal array.

[0080] 3) Keeping the silicon pillar template and the substrate pressed tightly, place the liquid metal array in a tubular furnace filled with nitrogen atmosphere, heat it to 1050°C at a heating rate of 10°C / min, introduce gaseous nitrogen source ammonia at a flow rate of 500sccm into the tubular furnace, and keep the reaction at this temperature for 180 minutes. Under the confinement effect of the silicon pillar template, the liquid metal pattern on the substrate reacts in situ with the continuously introduced ammonia to grow an AlGaN pattern.

[0081] 4) After the reaction is completed, stop introducing ammonia, continue introducing nitrogen, cool down to 750°C at a rate of 5°C / min, re-introduce ammonia at a flow rate of 500 sccm for annealing for 120 min, stop introducing ammonia and replace with nitrogen, cool down to room temperature at a rate of 5°C / min, and peel off the template to prepare an AlGaN pattern array.

[0082] like Figure 7a-7b As shown, the gallium-aluminum alloy array and the AlGaN array grown by in-situ confined reaction have neat edges, uniform morphology, and are highly ordered.

[0083] like Figure 8 As shown, the scanning electron microscope image of the AlGaN array grown based on the in-situ confined reaction of liquid metal shows that the array has uniform morphology, high order and accurate position, and the energy spectrum data graph shows that the elements are evenly distributed and aluminum is successfully doped.

[0084] Example 4

[0085] like Figure 1a-1b As shown, a method for in-situ confined reaction growth of a gallium nitride single crystal array with adjustable bandgap, preparing a gallium chloride array and an in-situ confined reaction growth GaN pattern, comprises the following steps:

[0086] 1) A silicon pillar template having a plurality of silicon pillar arrays is prepared by photolithography, each silicon pillar having a width of 4 μm, a spacing of 20 μm, and a height of 15 μm, and an asymmetric wettability modification treatment is performed on the silicon pillar to make the top of the silicon pillar hydrophilic and the side wall hydrophobic.

[0087] 2) In an anhydrous and oxygen-free environment, the top of the silicon column template is pressed against the quartz substrate, and 15 μL of anhydrous gallium chloride DMF solution with a concentration of 0.5 mmol / mL is injected into the hole on one side of the quartz substrate. The gallium chloride solution flows along the top of the column under the confinement of the silicon column template. After the solvent is evaporated, a gallium chloride patterned array is prepared as shown in FIG. Figure 9a As shown, the gallium chloride array has neat edges, uniform morphology, and is highly ordered.

[0088] 3) Keeping the silicon pillar template and the substrate pressed tightly, place the gallium source array in a tubular furnace filled with nitrogen atmosphere, heat it to 1000°C at a heating rate of 10°C / min, introduce gaseous nitrogen source ammonia at a flow rate of 500sccm into the tubular furnace, and keep the reaction for 120 minutes. Under the confinement effect of the silicon pillar template, the gallium source pattern on the substrate reacts in situ with the continuously introduced ammonia to grow GaN single crystals.

[0089] 4) After the reaction is completed, stop introducing ammonia, continue introducing nitrogen, cool down to 750°C at a rate of 5°C / min, introduce ammonia at a flow rate of 500 sccm again for annealing for 90 min, stop introducing ammonia and replace with nitrogen, cool down to room temperature at a rate of 5°C / min, and peel off the template to prepare a gallium nitride single crystal pattern as shown in Figure 9b As shown, the in-situ confined reaction grown gallium nitride single crystal pattern has neat edges, uniform morphology, and is highly ordered.

[0090] like Fig.10 As shown, the characteristic peaks show that the GaN single crystal array has a hexagonal phase structure.

[0091] Example 5

[0092] like Figure 1a-1b As shown, a method for in-situ confined reaction growth of a bandgap adjustable gallium nitride single crystal array, preparation of gallium chloride and indium chloride arrays and in-situ confined reaction growth of InGaN patterns, comprising the following steps:

[0093] 1) A silicon pillar template having a plurality of silicon pillar arrays is prepared by photolithography, each silicon pillar having a width of 4 μm, a spacing of 20 μm, and a height of 15 μm, and an asymmetric wettability modification treatment is performed on the silicon pillar to make the top of the silicon pillar hydrophilic and the side wall hydrophobic.

[0094] 2) In an anhydrous and oxygen-free environment, the top of the silicon column template is pressed against a quartz substrate, and 15 μL of a DMF mixed solution of anhydrous gallium chloride and indium chloride with a concentration of 0.5 mmol / mL and a Ga:In molar ratio of 1:1 is injected into the hole on one side of the quartz substrate. The solution flows directionally along the top of the column under the confinement of the silicon column template, and the metal halide array is prepared after the solvent is evaporated.

[0095] 3) Keeping the silicon pillar template and the substrate pressed tightly, place the metal halide array in a tubular furnace filled with nitrogen atmosphere, heat it to 950°C at a heating rate of 10°C / min, introduce gaseous nitrogen source ammonia at a flow rate of 500sccm into the tubular furnace, and keep the reaction at this temperature for 200 minutes. Under the confinement effect of the silicon pillar template, the liquid metal pattern on the substrate reacts in situ with the continuously introduced ammonia to grow an InGaN pattern.

[0096] 4) After the reaction is completed, stop introducing ammonia, continue introducing nitrogen, cool down to 750°C at a rate of 5°C / min, re-introduce ammonia at a flow rate of 500 sccm for annealing for 90 minutes, stop introducing ammonia and replace with nitrogen, cool down to room temperature at a rate of 5°C / min, and peel off the template to prepare an InGaN pattern array.

[0097] The effect of the InGaN pattern array is close to that of Example 2.

[0098] Example 6

[0099] like Figure 1a-1b As shown, a method for in-situ confined reaction growth of a bandgap adjustable gallium nitride single crystal array, preparation of gallium chloride and aluminum chloride arrays and in-situ confined reaction growth of AlGaN patterns, includes the following steps:

[0100] 1) A silicon pillar template having a plurality of silicon pillar arrays is prepared by photolithography, each silicon pillar having a width of 4 μm, a spacing of 20 μm, and a height of 15 μm, and an asymmetric wettability modification treatment is performed on the silicon pillar to make the top of the silicon pillar hydrophilic and the side wall hydrophobic.

[0101] 2) In an anhydrous and oxygen-free environment, the top of the silicon column template is pressed against a quartz substrate, and 15 μL of a DMF mixed solution of anhydrous gallium chloride and aluminum chloride with a concentration of 0.5 mmol / mL and a Ga:Al molar ratio of 1:1 is injected into the hole on one side of the quartz substrate. The solution flows directionally along the top of the column under the confinement of the silicon column template, and the metal halide array is prepared after the solvent is evaporated.

[0102] 3) Keeping the silicon pillar template and the substrate pressed tightly, place the metal halide array in a tubular furnace filled with nitrogen atmosphere, heat it to 1000-1100°C at a heating rate of 10°C / min, introduce gaseous nitrogen source ammonia at a flow rate of 500sccm into the tubular furnace, and keep the reaction for 180 minutes. Under the confinement effect of the silicon pillar template, the pattern on the substrate reacts in situ with the continuously introduced ammonia to grow an AlGaN pattern.

[0103] 4) After the reaction is completed, stop introducing ammonia, continue introducing nitrogen, cool down to 750°C at a rate of 5°C / min, re-introduce ammonia at a flow rate of 500 sccm for annealing for 90 minutes, stop introducing ammonia and replace with nitrogen, cool down to room temperature at a rate of 5°C / min, and peel off the template to prepare an AlGaN pattern array.

[0104] The AlGaN pattern array is similar to that of Example 3.

[0105] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array, characterized in that: The following steps are involved: S1, pressing the asymmetric wettable micro-pillar template against the substrate, injecting a gallium source from the hole on one side of the substrate, wherein the gallium source is a fluid, and the gallium source is directedly transmitted and flows along the top of the micro-pillar under the confinement of the micro-pillar template to obtain a gallium source array; S2, heating the gallium source array in a nitrogen source atmosphere to allow the gallium source array to undergo an in-situ chemical reaction with the nitrogen source to obtain a gallium nitride pattern array; S3. After cooling and annealing, the gallium nitride single crystal pattern array is peeled off from the micro-pillar template to obtain an in-situ grown gallium nitride pattern array. A method for in-situ confined reaction growth of a gallium nitride single crystal array with adjustable bandgap is completed.

2. The method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array according to claim 1, characterized in that: In step S1, the gallium source may be liquid metal gallium or an anhydrous gallium chloride solution. Indium or aluminum may be doped into the gallium source, and the band gap may be adjusted by changing the ratio of the doped metal.

3. The method for in-situ confined reaction growth of a bandgap adjustable gallium nitride single crystal array according to claim 1, characterized in that: In step S1, the gallium source is liquid metal gallium, and the gallium source array is a liquid metal gallium array; in an anhydrous and oxygen-free environment and under heating conditions of 50-60° C., liquid metal gallium is injected from the holes on one side of the substrate; In step S2, while keeping the micro-pillar template and the substrate pressed tightly, the liquid metal gallium array is placed in a nitrogen atmosphere, heated to 900-1000° C., and a nitrogen source is introduced, wherein the nitrogen source is ammonia gas. The heat preservation reaction time is 120-150 minutes, and the liquid metal gallium array and the ammonia gas undergo an in-situ chemical reaction to obtain a gallium nitride single crystal pattern array; In step S3, the nitrogen source atmosphere is introduced again for annealing when the temperature drops to 750°C, and then the gallium nitride single crystal pattern array is peeled off from the substrate after the temperature drops to room temperature to obtain an in-situ grown gallium nitride single crystal pattern array.

4. The method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array according to claim 1, characterized in that: In step S1, the gallium source is a liquid gallium-indium alloy, and the gallium source array is a liquid gallium-indium array; in an anhydrous and oxygen-free environment and under heating conditions of 30-120° C., the liquid gallium-indium alloy is injected from the holes on one side of the substrate, and the indium content of the liquid gallium-indium alloy is 20-50%; In step S2, while keeping the micro-column template and the substrate pressed tightly, the liquid metal gallium indium array is placed in a nitrogen atmosphere, heated to 850-950° C., a nitrogen source is introduced, and the nitrogen source is ammonia. The heat preservation reaction time is 120-150 minutes, and the liquid metal gallium indium array reacts with ammonia in situ to obtain an InGaN pattern array; In step S3, the nitrogen source atmosphere is introduced again to perform annealing when the temperature drops to 750°C, and then the InGaN pattern array is peeled off from the substrate after the temperature drops to room temperature to obtain an in-situ grown InGaN pattern array.

5. The method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array according to claim 1, characterized in that: In step S1, the gallium source is a liquid gallium-aluminum alloy, and the gallium source array is a liquid gallium-aluminum array; in an anhydrous and oxygen-free environment and under heating conditions of 550-650° C., the liquid gallium-aluminum alloy is injected from the hole on one side of the substrate, and the aluminum content in the liquid gallium-aluminum alloy is 20-50%; In step S2, while keeping the micro-column template and the substrate pressed tightly, the liquid metal gallium aluminum array is placed in a nitrogen atmosphere, heated to 950-1050° C., and a nitrogen source is introduced, wherein the nitrogen source is ammonia gas. The heat preservation reaction time is 150-180 minutes, and the liquid metal gallium aluminum array reacts with the ammonia gas in situ to obtain an AlGaN pattern array; In step S3, when the temperature is lowered to 750°C, the nitrogen source atmosphere is introduced again for annealing, and after the temperature is lowered to room temperature, the AlGaN pattern array is peeled off from the substrate to obtain an in-situ grown AlGaN pattern array.

6. The method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array according to claim 1, characterized in that: In step S1, the gallium source is a 0.25-0.5 mmol / mL DMF solution of anhydrous gallium chloride, and the gallium source array is a liquid metal gallium array; in an anhydrous and oxygen-free environment and under heating conditions of 550-650° C., the gallium source is injected from the holes on one side of the substrate, and the gallium source array is obtained after the solvent is evaporated, and the gallium source array is a gallium chloride array; In step S2, while keeping the micro-pillar template and the substrate pressed tightly, the gallium source array is placed in a nitrogen atmosphere, heated to 900-1000° C., and a nitrogen source is introduced, wherein the nitrogen source is ammonia gas. The heat preservation reaction time is 90-120 minutes, and the gallium chloride array and the ammonia gas react in situ to obtain a gallium nitride single crystal pattern array; In step S3, the nitrogen source atmosphere is introduced again for annealing when the temperature drops to 750°C, and then the gallium nitride single crystal pattern array is peeled off from the substrate after the temperature drops to room temperature to obtain an in-situ grown gallium nitride single crystal pattern array.

7. The method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array according to claim 1, characterized in that: In step S1, the gallium source is a DMF mixed solution of anhydrous gallium chloride and indium chloride with a concentration of 0.25-0.5 mmol / mL and a Ga:In molar ratio of 4:1-1:1, and the gallium source array is a metal halide array; in an anhydrous and oxygen-free environment, the gallium source is injected from the hole on one side of the substrate, and the gallium source array is obtained after the solvent is evaporated, and the gallium source array is a metal halide array; In step S2, while keeping the micro-pillar template and the substrate pressed tightly, the gallium source array is placed in a nitrogen atmosphere, heated to 850-950° C., and a nitrogen source is introduced, wherein the nitrogen source is ammonia gas. The heat preservation reaction time is 180-200 minutes, and the metal halide array and the ammonia gas react in situ to obtain an InGaN pattern array; In step S3, the nitrogen source atmosphere is introduced again to perform annealing when the temperature drops to 750°C, and then the InGaN pattern array is peeled off from the substrate after the temperature drops to room temperature to obtain an in-situ grown InGaN pattern array.

8. The method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array according to claim 1, characterized in that: In step S1, the gallium source is a DMF mixed solution of anhydrous gallium chloride and aluminum chloride with a concentration of 0.25-0.5 mmol / mL and a Ga:Al molar ratio of 4:1-1:1, and the gallium source array is a metal halide array; the gallium source is injected from the holes on one side of the substrate in an anhydrous and oxygen-free environment, and the gallium source array is obtained after the solvent is evaporated, and the gallium source array is a metal halide array; In step S2, while keeping the micro-pillar template and the substrate pressed tightly, the gallium source array is placed in a nitrogen atmosphere, heated to 1000-1100° C., and a nitrogen source is introduced, wherein the nitrogen source is ammonia gas. The heat preservation reaction time is 120-180 minutes, and the metal halide array and the ammonia gas react in situ to obtain an AlGaN pattern array; In step S3, when the temperature is lowered to 750°C, the nitrogen source atmosphere is introduced again for annealing, and after the temperature is lowered to room temperature, the AlGaN pattern array is peeled off from the substrate to obtain an in-situ grown AlGaN pattern array.

9. The method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array according to claim 1, characterized in that: In step S1, the asymmetric wettable microcolumn template includes microcolumns arranged in an array, the microcolumns are modified by asymmetric wettability to make the top hydrophilic and the sidewall hydrophobic, the interval of the microcolumns is 1-100 μm, the width is 1-100 μm, and the height is 10-100 μm. The shape of the microcolumns is a straight line, a rectangle, a triangle, or a ring, and the asymmetric wettable microcolumn template is prepared by photolithography; The material of the microcolumn is silicon, and the substrate is any one of the following: silicon wafer, sapphire, quartz wafer, silicon dioxide wafer, gold wafer, silver wafer and platinum wafer; In step S1, the injection amount of the gallium source is 15 μL.

10. The method for in-situ confined reaction growth of a bandgap-adjustable gallium nitride single crystal array according to any one of claims 1 to 9, characterized in that: In step S2, the micro-column template and the substrate are kept pressed tightly, and the gallium source array is placed in a tubular furnace filled with a nitrogen atmosphere, and the temperature is raised to a first specified temperature at a heating rate of 10° C. / min, and then ammonia is introduced into the tubular furnace at a flow rate of 300-500 sccm to cause an in-situ chemical reaction, and then the reaction is kept warm; In step S3, after the in-situ chemical reaction is completed, the introduction of ammonia is stopped and nitrogen is continued, and the temperature is lowered to the second specified temperature at a rate of 5°C / min, and then ammonia with a flow rate of 300-500sccm is introduced again for annealing for 90-120min. After the annealing is completed, the introduction of ammonia is stopped and nitrogen is introduced instead, and then the temperature is lowered to room temperature at a rate of 5°C / min.

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