Preparation method of indium phosphide single crystal and indium phosphide single crystal

Abstract

The invention provides a preparation method of an indium phosphide single crystal and the indium phosphide single crystal which can be applied to the technical field of semiconductors. The method comprises the steps that polycrystalline synthesis raw materials are adopted to synthesize indium phosphide polycrystals, the polycrystalline synthesis raw materials comprise a first raw material and a second raw material, the first raw material comprises high-purity indium and indium oxide, the second raw material is high-purity red phosphorus, the indium oxide can be decomposed into oxygen and indium, and indium phosphide single crystals grow on the basis of the indium phosphide polycrystals, and cleaning the indium phosphide single crystal by using an ultraviolet-ozone method. The indium oxide can be decomposed into oxygen and indium, and the oxygen and carbon generate carbon dioxide gas, so that carbon contamination and organic contamination in the raw materials can be effectively removed, and new impurities cannot be introduced. A drying medium is used for ultraviolet-ozone treatment, the requirement for immersing the whole equipment assembly and raw materials into a treatment solution is omitted, and when ultraviolet radiation and ozone are used in a combined mode, carbon pollutants and organic matter pollutants can be efficiently removed at the same time.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a method for preparing an indium phosphide single crystal and an indium phosphide single crystal. Background Art

[0002] Indium phosphide (InP) is an important III-V compound semiconductor material with a direct transition band structure and a large bandgap, and can be widely used in optical fiber communication projects. InP has high electron mobility and strong radiation resistance, and can be used in integrated circuits and high-speed and high-frequency devices. At the same time, InP has excellent properties of good thermal conductivity and high photoelectric conversion efficiency, and can be used to prepare solar cells. In recent years, with the continuous development of InP-based devices, the requirements for the quality of InP materials, especially the purity of materials, have become increasingly higher.

[0003] There is carbon contamination and organic contamination in the process of taking polycrystalline raw materials. The indium raw materials and phosphorus raw materials used in the polycrystalline synthesis process have carbon impurities, so the InP polycrystal contains carbon impurities, and the subsequent polycrystalline material crushing process is also very susceptible to organic contamination. In the single crystal synthesis process, the boron nitride crucible and growth tube are susceptible to carbon contamination and organic contamination during the process of taking. Carbon contamination affects the electrical, optical, thermal conductivity and mechanical properties of the material. Therefore, it is necessary to conduct in-depth research on methods and ways to reduce the carbon content in indium phosphide single crystals. Summary of the invention

[0004] In view of the above problems, the present disclosure provides a method for preparing an indium phosphide single crystal and an indium phosphide single crystal.

[0005] According to a first aspect of the present disclosure, a method for preparing an indium phosphide single crystal is provided, characterized in that the method comprises:

[0006] Synthesizing indium phosphide polycrystals using polycrystalline synthesis raw materials, the polycrystalline synthesis raw materials comprising a first raw material and a second raw material, the first raw material comprising high-purity indium and indium oxide, the second raw material being high-purity red phosphorus, and the indium oxide being decomposable into oxygen and indium;

[0007] Based on the indium phosphide polycrystal, growing an indium phosphide single crystal;

[0008] The indium phosphide single crystal is cleaned by using an ultraviolet-ozone method.

[0009] According to an embodiment of the present disclosure, the method of synthesizing indium phosphide polycrystal using polycrystal synthesis raw materials includes:

[0010] High-purity indium and a certain proportion of high-purity indium oxide are placed in a quartz boat, and high-purity red phosphorus is placed in another quartz boat;

[0011] Put two quartz boats into quartz tubes respectively, and evacuate and seal the quartz tubes;

[0012] InP polycrystals were synthesized using high pressure horizontal gradient directional solidification.

[0013] According to an embodiment of the present disclosure, before synthesizing indium phosphide polycrystal using polycrystalline synthesis raw materials, the process includes:

[0014] Remove contamination from the surface of the device required for synthesizing indium phosphide polycrystal and dry it;

[0015] The devices required for synthesizing the indium phosphide polycrystal are cleaned by using an ultraviolet-ozone method.

[0016] According to an embodiment of the present disclosure, growing an indium phosphide single crystal based on the indium phosphide polycrystal includes:

[0017] breaking the indium phosphide polycrystal into blocks to obtain block-shaped indium phosphide polycrystals;

[0018] removing contamination from the surface of the blocky indium phosphide polycrystal and drying the blocky indium phosphide polycrystal;

[0019] Cleaning the bulk indium phosphide polycrystal by ultraviolet-ozone method;

[0020] Removing contamination from the surface of devices required for growing indium phosphide single crystals and drying the devices, wherein the devices required for growing indium phosphide single crystals include a boron nitride crucible, a growth tube and a quartz cap;

[0021] Indium phosphide single crystals were grown using vertical gradient solidification.

[0022] According to an embodiment of the present disclosure, the method further includes:

[0023] The carbon content in the indium phosphide single crystal is analyzed by low temperature Fourier transform infrared transmission method;

[0024] The mobility of the indium phosphide single crystal is tested.

[0025] According to an embodiment of the present disclosure, removing contamination from the surface of a device required for synthesizing indium phosphide polycrystals includes:

[0026] The devices required for synthesizing indium phosphide polycrystals are cleaned in turn using detergent, an acidic cleaning solution and deionized water, wherein the acidic cleaning solution comprises hydrofluoric acid in a volume ratio of 0-1, nitric acid in a volume ratio of 1-10 and water in a volume ratio of 0-1, the mass fraction of nitric acid is 42%, and the mass fraction of hydrofluoric acid is 40%.

[0027] According to an embodiment of the present disclosure, the step of removing contamination from the surface of the bulk indium phosphide polycrystal includes:

[0028] The bulk indium phosphide polycrystal is cleaned with an alkaline cleaning solution and deionized water in sequence, wherein the alkaline cleaning solution comprises ammonium hydroxide, hydrogen peroxide, and water in a volume ratio of 1-10, 0-2, and 0-5, wherein the mass fraction of the ammonium hydroxide is 25%, and the mass fraction of the hydrogen peroxide is 25%;

[0029] The method of removing contamination from the surface of the device required for growing the indium phosphide single crystal comprises:

[0030] The devices required for growing indium phosphide single crystals are cleaned in turn using detergent, an acidic cleaning solution and deionized water, wherein the acidic cleaning solution comprises hydrofluoric acid, nitric acid and water in a volume ratio of 0-1, 1-10, and 0-1, wherein the mass fraction of nitric acid is 42% and the mass fraction of hydrofluoric acid is 40%.

[0031] According to the disclosed embodiment, the cleaning temperature range of the UV-ozone method is 25-200°C;

[0032] The cleaning time of the UV-ozone method ranges from 10 to 60 minutes;

[0033] The ultraviolet wavelength range used in the ultraviolet-ozone method is 175-195nm and 245-265nm;

[0034] The ozone concentration range used in the UV-ozone method is 10-100 mg / L.

[0035] According to an embodiment of the present disclosure, the weight of the indium oxide is 5%-30% of the weight of the high-purity indium.

[0036] According to a second aspect of the present disclosure, an indium phosphide single crystal is also provided. The indium phosphide single crystal is prepared by the method described in the first aspect.

[0037] According to the preparation method of indium phosphide single crystal and indium phosphide single crystal provided by the embodiment of the present disclosure, indium phosphide polycrystal is synthesized by using polycrystalline synthesis raw materials, the polycrystalline synthesis raw materials include a first raw material and a second raw material, the first raw material includes high-purity indium and indium oxide, the second raw material is high-purity red phosphorus, indium oxide can be decomposed into oxygen and indium, based on indium phosphide polycrystal, indium phosphide single crystal is grown, and the indium phosphide single crystal is cleaned by ultraviolet-ozone method. Since indium oxide can be decomposed into oxygen and indium, oxygen and carbon generate carbon dioxide gas, carbon contamination and organic contamination in the raw material can be effectively removed without introducing new impurities. The ultraviolet-ozone treatment uses a dry medium, which saves the need to immerse the entire equipment assembly and raw materials in the treatment solution. When ultraviolet radiation is used in combination with ozone, carbon pollutants and organic pollutants can be efficiently removed at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above contents and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0039] Figure 1 A flow chart schematically shows a method for preparing an indium phosphide single crystal according to an embodiment of the present disclosure;

[0040] Figure 2 The low-temperature Fourier transform infrared spectra of the indium phosphide single crystal in Example 1 and Comparative Example 1 according to the embodiments of the present disclosure are schematically shown. DETAILED DESCRIPTION

[0041] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0042] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0043] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0044] The present invention provides a method for preparing an indium phosphide single crystal. The indium phosphide polycrystal is synthesized by using a polycrystalline synthetic raw material. The polycrystalline synthetic raw material includes a first raw material and a second raw material. The first raw material includes high-purity indium and indium oxide. The second raw material is high-purity red phosphorus. The indium oxide can be decomposed into oxygen and indium. Based on the indium phosphide polycrystal, an indium phosphide single crystal is grown. The indium phosphide single crystal is cleaned by using an ultraviolet-ozone method. By adding a certain proportion of high-purity indium oxide to the high-purity indium raw material, carbon contamination in the polycrystalline synthetic raw material is removed without introducing new impurities. By using the ultraviolet-ozone method, ultraviolet radiation and ozone are combined to remove carbon contamination of the material and degrade organic pollutants, and the treatment process does not require the entire equipment and material to be immersed in a treatment solution.

[0045] Figure 1 The flowchart of the method for preparing an indium phosphide single crystal according to an embodiment of the present disclosure is schematically shown.

[0046] like Figure 1 As shown, the method for preparing an indium phosphide single crystal in this embodiment includes operations S110 to S130.

[0047] In operation S110, polycrystalline indium phosphide polycrystal is synthesized using a polycrystalline synthesis raw material, the polycrystalline synthesis raw material includes a first raw material and a second raw material, the first raw material includes high-purity indium and indium oxide, the second raw material is high-purity red phosphorus, and indium oxide can be decomposed into oxygen and indium.

[0048] In operation S120 , an indium phosphide single crystal is grown based on the indium phosphide polycrystal.

[0049] In operation S130 , the indium phosphide single crystal is cleaned using an ultraviolet-ozone method.

[0050] A certain proportion of indium oxide is added to the high-purity indium as the raw material for polycrystalline synthesis. Indium oxide is chemically unstable. When the temperature is below the melting point, indium oxide will decompose into O2 and In. The generated O2 and C will generate gaseous CO2, thereby achieving the purpose of removing carbon contamination in the raw material. The reaction formula is as follows:

[0051]

[0052]

[0053] UV-ozone cleaning can effectively remove carbon and other types of organic contamination. The reaction mechanism of UV-ozone process for degrading organic pollutants and removing carbon contamination mainly includes direct photodegradation by ultraviolet light, oxidative degradation by ozone and indirect oxidative degradation by generated free radicals, among which the indirect oxidative degradation of pollutants by a large amount of ·OH generated by ozone molecules under ultraviolet radiation is dominant.

[0054] In some embodiments, the method for synthesizing indium phosphide polycrystals can be: high-purity indium and a certain proportion of high-purity indium oxide are placed in a quartz boat, and high-purity red phosphorus is placed in another quartz boat; the two quartz boats are placed in quartz tubes respectively, and the quartz tubes are evacuated and sealed; and indium phosphide polycrystals are synthesized using a high-pressure horizontal gradient directional solidification method.

[0055] In some embodiments, before using polycrystalline synthesis raw materials to synthesize indium phosphide polycrystals, contamination on the surface of the device required for synthesizing indium phosphide polycrystals can be removed and dried, and then the device required for synthesizing indium phosphide polycrystals can be cleaned using an ultraviolet-ozone method.

[0056] The devices required for synthesizing indium phosphide polycrystals include quartz tubes, quartz boats, quartz caps, etc.

[0057] In some embodiments, the method of growing an indium phosphide single crystal may be: breaking an indium phosphide polycrystal into blocks to obtain a block of indium phosphide polycrystal; removing contamination from the surface of the block of indium phosphide polycrystal and drying it; cleaning the block of indium phosphide polycrystal using an ultraviolet-ozone method; removing contamination from the surface of a device required for growing an indium phosphide single crystal and drying it. Growing an indium phosphide single crystal using a vertical gradient solidification method.

[0058] The devices required for growing indium phosphide single crystals include boron nitride crucibles, growth tubes, quartz caps, etc.

[0059] In some embodiments, a low-temperature Fourier transform infrared transmission method can also be used to analyze the carbon content in the indium phosphide single crystal; and to test the mobility of the indium phosphide single crystal.

[0060] In some embodiments, removing contamination from the surface of a device required for synthesizing indium phosphide polycrystals may include: cleaning the device required for synthesizing indium phosphide polycrystals with detergent, an acidic cleaning solution, and deionized water in sequence, wherein the volume ratio of hydrofluoric acid, nitric acid, and water in the acidic cleaning solution is (0-1): (1-10): (0-1), the mass fraction of nitric acid is 42%, and the mass fraction of hydrofluoric acid is 40%.

[0061] In some embodiments, removing contamination from the surface of bulk indium phosphide polycrystals may include: cleaning the bulk indium phosphide polycrystals with an alkaline cleaning solution and deionized water in sequence, wherein the volume ratio of ammonium hydroxide, hydrogen peroxide, and water in the alkaline cleaning solution is (1-10): (0-2): (0-5), the mass fraction of ammonium hydroxide is 25%, and the mass fraction of hydrogen peroxide is 25%.

[0062] In some embodiments, removing contamination from the surface of a device required for growing an indium phosphide single crystal may include: cleaning the device required for growing an indium phosphide single crystal using detergent, an acidic cleaning solution, and deionized water in sequence, wherein the volume ratio of hydrofluoric acid, nitric acid, and water in the acidic cleaning solution is (0-1): (1-10): (0-1), the mass fraction of nitric acid is 42%, and the mass fraction of hydrofluoric acid is 40%.

[0063] In some embodiments, the cleaning temperature of the UV-ozone method ranges from 25-200° C. The cleaning temperature of the UV-ozone method is, for example, 25° C., 50° C., 200° C., and the like.

[0064] In some embodiments, the cleaning time of the UV-ozone method ranges from 10 to 60 minutes, such as 10 minutes, 15 minutes, 60 minutes, and the like.

[0065] In some embodiments, the ultraviolet wavelength range used in the ultraviolet-ozone method is 175-195nm and 245-265nm. The coexistence of two ultraviolet rays with ultraviolet wavelengths ranging from 175-195nm and 245-265nm will lead to the continuous formation of atomic oxygen, as well as the continuous generation and decomposition of ozone. The atomic oxygen formed in the process of ozone formation and destruction acts as a strong oxidant, which can successfully reduce carbon contamination and organic contamination in raw and auxiliary materials. The ultraviolet wavelength used in the ultraviolet-ozone method is, for example, 175nm, 185nm, 195nm, 245nm, 254nm, 265nm, etc.

[0066] In some embodiments, the ozone concentration used in the UV-ozone method ranges from 10 to 100 mg / L, and the ozone concentration used in the UV-ozone method is, for example, 10 mg / L, 50 mg / L, or 100 mg / L.

[0067] In some embodiments, the weight of indium oxide is 5%-30% of the weight of high-purity indium. For example, the weight of indium oxide is 5% of the weight of high-purity indium, the weight of indium oxide is 15% of the weight of high-purity indium, and the weight of indium oxide is 30% of the weight of high-purity indium.

[0068] The technical solution of the present invention is further described below through specific embodiments.

[0069] Embodiment 1:

[0070] This embodiment provides a method for preparing an indium phosphide single crystal, including operations (1) to (6).

[0071] (1) The quartz tube, quartz boat and quartz cap used for polycrystalline synthesis are cleaned and dried with a cleaning solution, and then further cleaned using a UV-ozone method.

[0072] Specifically, before polycrystalline synthesis, the quartz tube and quartz boat caps for polycrystalline synthesis are cleaned of attachments and dust on the inner and outer surfaces with a brush and detergent, then immersed in an acidic cleaning solution for 3 minutes, then rinsed with deionized water and dried in a fume hood, and finally treated with UV-ozone for 30 minutes to reduce carbon contamination in the polycrystalline synthesis process, wherein the volume ratio of hydrofluoric acid, nitric acid and water in the acidic cleaning solution is 1:10:1, wherein the mass fraction of nitric acid is 42%, and the mass fraction of hydrofluoric acid is 40%; the ultraviolet wavelengths are 185nm and 254nm, and the ozone concentration is 20mg / L.

[0073] (2) High-purity indium and a certain proportion of high-purity indium oxide are placed in a quartz boat, high-purity red phosphorus is placed in another quartz boat, and the two quartz boats are placed in quartz tubes respectively. The quartz tubes are evacuated, and the sealed quartz tubes are sintered at high temperature using a hydrogen-oxygen flame. The sealed quartz tubes are then placed in a polycrystalline synthesis furnace, and indium phosphide polycrystals are synthesized using a high-pressure horizontal gradient directional solidification method. The mobility of the synthesized polycrystals is tested.

[0074] (3) After the indium phosphide polycrystals are synthesized, the indium phosphide polycrystals are broken into blocks, alkali washed, and dried, and then the block indium phosphide polycrystals are further cleaned by a UV-ozone method.

[0075] The indium phosphide polycrystals were knocked into pieces, and the blocky indium phosphide polycrystals were soaked in an alkaline cleaning solution for 20 minutes, then rinsed with deionized water, and dried in a fume hood without using the UV-ozone cleaning method. The volume ratio of ammonium hydroxide, hydrogen peroxide, and water in the alkaline cleaning solution was 1:1:5, with the mass fraction of ammonium hydroxide being 25% and the mass fraction of hydrogen peroxide being 25%. The ultraviolet wavelengths were 185nm and 254nm, and the ozone concentration was 20mg / L.

[0076] (4) The boron nitride crucible, growth tube and quartz cap used for single crystal growth are cleaned and dried with a cleaning solution, and then further cleaned using a UV-ozone method.

[0077] Before the single crystal growth, the boron nitride crucible, growth tube and graphite cap for single crystal growth are first cleaned with a brush and detergent to remove the attachments and dust on the inner and outer surfaces, then soaked in an acidic cleaning solution for 3 minutes, then rinsed with deionized water and dried in a fume hood without using the UV-ozone cleaning method. After that, the material is sealed and the tube is installed, and the single crystal is grown using the vertical gradient solidification method. The volume ratio of hydrofluoric acid, nitric acid and water in the acidic cleaning solution is 1:10:1, of which the mass fraction of nitric acid is 42% and the mass fraction of hydrofluoric acid is 40%. The ultraviolet wavelength is 185nm and 254nm, and the ozone concentration is 20mg / L.

[0078] (5) Indium phosphide single crystals were grown using the vertical gradient solidification method.

[0079] (6) The carbon content in the grown InP single crystal was tested by low temperature Fourier transform infrared transmission method. The mobility of the grown InP single crystal was also tested.

[0080] Embodiment 2:

[0081] The specific methods, steps and solution ratios mentioned in this embodiment are the same as those in Example 1, and the amount of indium oxide added is also the same as in Example 1, which is 15% of the weight of the high-purity indium raw material. Only the time for treating the raw and auxiliary materials using the UV-ozone method is different. In this embodiment, the UV-ozone cleaning time is 45 minutes.

[0082] Embodiment three:

[0083] The specific methods, steps and solution ratios mentioned in this embodiment are the same as those in Example 1, and the amount of indium oxide added is also the same as in Example 1, which is 15% of the weight of the high-purity indium raw material. Only the time for treating the raw and auxiliary materials with the UV-ozone method is different. In this embodiment, the UV-ozone cleaning time is 60 minutes.

[0084] Comparative Example 1:

[0085] This comparative example is in contrast to Example 1. In the comparative example 1, indium oxide is not added to the high-purity indium raw material, and UV-ozone is not used to clean the production equipment and the polycrystalline raw material. The specific method is as follows:

[0086] (10) Before polycrystalline synthesis, the quartz tube and quartz boat cap for polycrystalline synthesis were cleaned of attachments and dust on the inner and outer surfaces with a brush and detergent, then soaked in an acidic cleaning solution for 3 minutes, then rinsed with deionized water and dried in a fume hood. UV-ozone cleaning was not used. The volume ratio of hydrofluoric acid, nitric acid and water in the acidic cleaning solution was 1:10:1, with the mass fraction of nitric acid being 42% and the mass fraction of hydrofluoric acid being 40%.

[0087] (20) During the polycrystal synthesis process, high-purity indium is placed in a quartz boat, high-purity red phosphorus is placed in another quartz boat, and the two quartz boats are placed in quartz tubes respectively. The quartz tubes are evacuated, and the sealed quartz tubes are sintered at high temperature using a hydrogen-oxygen flame. The sealed quartz tubes are then placed in a polycrystal synthesis furnace, and indium phosphide polycrystals are synthesized using a high-pressure horizontal gradient directional solidification method. The mobility of the synthesized polycrystals is then tested.

[0088] (30) The indium phosphide polycrystalline material was broken into pieces, and the broken polycrystalline material was soaked in an alkaline cleaning solution for 20 minutes, then rinsed with deionized water, and dried in a fume hood without using the UV-ozone cleaning method. The volume ratio of ammonium hydroxide, hydrogen peroxide and water in the alkaline cleaning solution was 1:1:5, wherein the mass fraction of ammonium hydroxide was 25%, and the mass fraction of hydrogen peroxide was 25%. The ultraviolet wavelength was 185nm and 254nm, and the ozone concentration was 20mg / L.

[0089] (40) Before the growth of an indium phosphide single crystal, the boron nitride crucible, growth tube and graphite cap used for the growth of the indium phosphide single crystal are first cleaned of the attachments and dust on the inner and outer surfaces with a brush and detergent, then soaked in an acidic cleaning solution for 3 minutes, then rinsed with deionized water and dried in a fume hood without using an ultraviolet-ozone cleaning method, and then sealed and tubed, and the indium phosphide single crystal is grown using a vertical gradient solidification method. The volume ratio of hydrofluoric acid, nitric acid and water in the acidic cleaning solution is 1:10:1, wherein the mass fraction of nitric acid is 42% and the mass fraction of hydrofluoric acid is 40%. The ultraviolet wavelength is 185nm and 254nm, and the ozone concentration is 20mg / L.

[0090] (50) The carbon content in the grown InP single crystals was analyzed by low temperature Fourier transform infrared transmission method. The mobility of the grown InP single crystals was also tested.

[0091] The mobility and carrier concentration of the indium phosphide single crystal and indium phosphide polycrystal generated in Example 1 and Comparative Example 1 are shown in Table 1. Carbon is an acceptor in indium phosphide and will generate the same number of holes. The carbon content of undoped indium phosphide decreases, the ratio of acceptors compensating donors decreases, and the mobility and carrier concentration of indium phosphide increase. Therefore, the carbon content can be qualitatively reflected by the mobility and carrier concentration of indium phosphide polycrystal and single crystal.

[0092] Table 1

[0093]

[0094] The low temperature Fourier transform infrared spectra of the single crystals generated in Example 1 and Comparative Example 1 are shown in Figure 2 . Among them, the wavelength of 2844.2cm-1 is the absorption peak of CH. The single crystal grown in Example 1 using the polycrystalline synthesis raw material with added high-purity indium oxide and the UV-ozone cleaning raw and auxiliary materials has no absorption peak of CH, and the single crystal grown in the control example 1 without adding high-purity indium oxide and the polycrystalline synthesis raw and auxiliary materials with UV-ozone treatment has an obvious absorption peak of CH. The embodiment of the present invention combines theory with practice. According to the fact that indium oxide is very easy to decompose into oxygen and gaseous indium under high temperature conditions, oxygen will be contaminated with carbon to synthesize carbon dioxide gas. Adding indium oxide to high-purity indium can reduce carbon contamination in polycrystalline raw materials and polycrystalline synthesis processes. The coexistence of ultraviolet rays with wavelengths of 185nm and 254nm will lead to the continuous formation of atomic oxygen, as well as the continuous generation and decomposition of ozone. The atomic oxygen formed in the process of ozone formation and destruction acts as a strong oxidant, successfully reducing the carbon contamination and organic contamination of raw and auxiliary materials.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Since various changes can be made in the above products and methods without departing from the scope of the present invention, it is intended that all the subject matter contained in the above description be understood as exemplary rather than restrictive. The above description of the embodiments is only intended to enable other technicians in the field to understand the present invention, its principles and its practical applications, so that other technicians in the field can adjust and apply the present invention in various forms to best suit the requirements of specific applications.

[0096] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations and / or combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways without departing from the spirit and teachings of the present disclosure. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0097] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. The scope of the present disclosure is defined by the attached claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A method for preparing an indium phosphide single crystal, characterized in that: The method comprises: Synthesizing indium phosphide polycrystals using polycrystalline synthesis raw materials, the polycrystalline synthesis raw materials comprising a first raw material and a second raw material, the first raw material comprising high-purity indium and indium oxide, the second raw material being high-purity red phosphorus, and the indium oxide being decomposable into oxygen and indium; Based on the indium phosphide polycrystal, growing an indium phosphide single crystal; The indium phosphide single crystal is cleaned by using an ultraviolet-ozone method.

2. The method according to claim 1, characterized in that The method of synthesizing indium phosphide polycrystal using polycrystal synthesis raw materials comprises: High-purity indium and a certain proportion of high-purity indium oxide are placed in a quartz boat, and high-purity red phosphorus is placed in another quartz boat; Put two quartz boats into quartz tubes respectively, and evacuate and seal the quartz tubes; InP polycrystals were synthesized using high pressure horizontal gradient directional solidification.

3. The method according to claim 1, characterized in that Before synthesizing indium phosphide polycrystal using polycrystal synthesis raw materials, the method includes: Remove contamination from the surface of the device required for synthesizing indium phosphide polycrystal and dry it; The devices required for synthesizing the indium phosphide polycrystal are cleaned by using an ultraviolet-ozone method.

4. The method according to claim 1, characterized in that: The step of growing an indium phosphide single crystal based on the indium phosphide polycrystal comprises: breaking the indium phosphide polycrystal into blocks to obtain block-shaped indium phosphide polycrystals; removing contamination from the surface of the blocky indium phosphide polycrystal and drying the blocky indium phosphide polycrystal; Cleaning the bulk indium phosphide polycrystal by ultraviolet-ozone method; Removing contamination from the surface of devices required for growing indium phosphide single crystals and drying the devices, wherein the devices required for growing indium phosphide single crystals include a boron nitride crucible, a growth tube and a quartz cap; Indium phosphide single crystals were grown using vertical gradient solidification.

5. The method according to claim 1, characterized in that The method further comprises: The carbon content in the indium phosphide single crystal is analyzed by low temperature Fourier transform infrared transmission method; The mobility of the indium phosphide single crystal is tested.

6. The method according to claim 3, characterized in that The method of removing contamination from the surface of the device required for synthesizing indium phosphide polycrystal comprises: The devices required for synthesizing indium phosphide polycrystals are cleaned in turn using detergent, an acidic cleaning solution and deionized water, wherein the acidic cleaning solution comprises hydrofluoric acid in a volume ratio of 0-1, nitric acid in a volume ratio of 1-10 and water in a volume ratio of 0-1, the mass fraction of nitric acid is 42%, and the mass fraction of hydrofluoric acid is 40%.

7. The method according to claim 4, characterized in that The method of removing contamination from the surface of the bulk indium phosphide polycrystal comprises: The bulk indium phosphide polycrystal is cleaned with an alkaline cleaning solution and deionized water in sequence, wherein the alkaline cleaning solution comprises ammonium hydroxide, hydrogen peroxide, and water in a volume ratio of 1-10, 0-2, and 0-5, wherein the mass fraction of the ammonium hydroxide is 25%, and the mass fraction of the hydrogen peroxide is 25%; The method of removing contamination from the surface of the device required for growing the indium phosphide single crystal comprises: The devices required for growing indium phosphide single crystals are cleaned in turn using detergent, an acidic cleaning solution and deionized water, wherein the acidic cleaning solution comprises hydrofluoric acid, nitric acid and water in a volume ratio of 0-1, 1-10, and 0-1, wherein the mass fraction of nitric acid is 42% and the mass fraction of hydrofluoric acid is 40%.

8. The method according to claim 1, characterized in that The cleaning temperature range of the UV-ozone method is 25-200°C; The cleaning time of the UV-ozone method ranges from 10 to 60 minutes; The ultraviolet wavelength range used in the ultraviolet-ozone method is 175-195nm and 245-265nm; The ozone concentration range used in the UV-ozone method is 10-100 mg / L.

9. The method according to claim 1, characterized in that: The weight of the indium oxide is 5%-30% of the weight of the high-purity indium.

10. An indium phosphide single crystal, characterized in that: The method is prepared by any one of claims 1 to 9.

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