Powder for growing gallium oxide single crystals and its manufacturing method

Abstract

To provide powder for growing a gallium oxide single crystal in which a raw material-crystal conversion rate is maximized, and to provide a method for manufacturing the same.SOLUTION: The present invention relates to powder for growing a gallium oxide single crystal and a method for manufacturing the same. The powder for growing a gallium oxide single crystal comprises a gallium oxide and has bulk density of 0.7 g / cm3 or more and 1.0 g / cm3 or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a powder for growing a gallium oxide single crystal and a method for producing the same, and more particularly to a powder for growing a gallium oxide single crystal with maximized conversion efficiency from a raw material to a single crystal and a method for producing the same. [Background technology]

[0002] Gallium oxide (Ga2O3) has been attracting attention as a material for next-generation power devices due to its wide band gap and high breakdown voltage. In particular, the demand for power devices is increasing with the recent spread of electric vehicles, and as high performance is required, the demand for gallium oxide is expected to increase sharply.

[0003] Regarding gallium oxide power devices, they are formed on gallium oxide single crystal substrates, and various single crystal growth techniques for manufacturing the gallium oxide single crystal substrates have been researched.

[0004] Among the methods for growing gallium oxide single crystals, the EFG (Edge-defined Film-fed Growth) method involves loading gallium oxide powder into a crucible, melting it, and then raising the molten gallium oxide through a slit to grow gallium oxide single crystals. The EFG method makes it easy to control defects in single crystals and has a relatively fast growth rate, making it possible to efficiently grow high-quality plate-shaped single crystals.

[0005] In order to grow a large-area gallium oxide single crystal, it is important to form as much gallium oxide melt as possible in the crucible.However, since the volume of the crucible is limited, the amount of gallium oxide powder that can be charged into the crucible is limited, and the amount of gallium oxide single crystal that grows from the melt of the charged gallium oxide powder is also limited.

[0006] In particular, since gallium oxide melts at high temperatures of 1,800°C or more, an iridium crucible, which has excellent heat resistance and fire resistance, is used. However, since iridium is an expensive material, there is a limit to how large the volume of the iridium crucible can be.

[0007] Even if a large amount of gallium oxide single crystal growth powder is charged into the crucible, there are cases where not all of the raw material is converted into a single crystal due to various reasons.

[0008] This calls for the development of a technology that allows the maximum amount of gallium oxide single crystal growth powder to be loaded into a limited crucible and, at the same time, allows the maximum amount of single crystals to be successfully grown from the gallium oxide single crystal growth powder.

[0009] In addition, the above-mentioned background art is technical information possessed by the inventor for the creation of the present invention or acquired in the process of creating the present invention, and is not publicly known art that was disclosed to the general public prior to the filing of the application for the present invention. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent No. 3987935 Summary of the Invention [Problem to be solved by the invention]

[0011] An object of one embodiment of the present invention is to provide a powder for growing a gallium oxide single crystal, in which the raw material-to-crystal conversion rate is maximized, and a method for producing the same. [Means for solving the problem]

[0012] According to one aspect of the present invention as a technical means for achieving the above-mentioned technical object, a powder for growing a gallium oxide single crystal is made of gallium oxide and has a bulk density of 0.7 g / cm 3 More than 1.0g / cm 3 The following is the result.

[0013] According to another aspect of the present invention, the powder for growing gallium oxide single crystals has a BET specific surface area of ​​1.5 m 2 / g or more 4.0m 2 / g or less.

[0014] According to another aspect of the present invention, the powder for growing gallium oxide single crystals may be composed of gallium oxide particles having a D50 particle size of 20 μm or less.

[0015] According to another aspect of the present invention, the gallium oxide particles may have an aspect ratio of 1 to 1.5.

[0016] According to another aspect of the present invention, the gallium oxide particles may be gallium oxide.

[0017] According to another aspect of the present invention as a technical means for achieving the above-mentioned technical object, a method for producing a powder for growing a gallium oxide single crystal includes a vaporization step of heating and vaporizing gallium, an oxidation step of oxidizing the vaporized gallium, a crystallization step of cooling and crystallizing the oxidized gallium oxide, a collection step of collecting the crystallized gallium oxide to obtain a gallium oxide powder, and a bulk density of the collected gallium oxide powder of 0.7 g / cm. 3 More than 1.0g / cm 3 and a densification step comprising:

[0018] According to another aspect of the present invention, the densification step may include a heat treatment step of heat treating the gallium oxide powder at a temperature of 1,200°C to 1,300°C.

[0019] According to another aspect of the invention, the heat treatment step may be carried out for 5 hours or more.

[0020] According to another aspect of the present invention, the powder for growing gallium oxide single crystals has a BET specific surface area of ​​1.5 m 2 / g or more 4.0m 2 / g or less.

[0021] The powder for growing gallium oxide single crystals may be composed of gallium oxide particles having a D50 particle size of 20 μm or less. Effect of the Invention

[0022] According to any one of the above-mentioned means for solving the problems of the present invention, a sufficient amount of powder for growing gallium oxide single crystals can be charged into a limited crucible, and a powder for growing gallium oxide single crystals having an excellent raw material-to-crystal conversion rate and a manufacturing method thereof can be provided.

[0023] In addition, according to any one of the means for solving the problems of the present invention, it is possible to maximize the raw material-crystal conversion rate and maximize the usage efficiency of the powder for growing gallium oxide single crystals, thereby reducing the manufacturing cost of gallium oxide single crystals.

[0024] The effects that can be obtained in the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the following description. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a flow chart for explaining a method for producing a powder for growing a gallium oxide single crystal according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a scanning electron microscope (SEM) photograph for comparing the particle morphology characteristics of powder before heat treatment in a method for producing a powder for growing a gallium oxide single crystal according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a SEM photograph of a powder for growing gallium oxide single crystals according to an embodiment obtained by heat-treating the gallium oxide powder according to Example 1 of FIG. [Figure 4] FIG. 4 is a conceptual diagram for explaining a method for growing a gallium oxide single crystal using a powder for growing a gallium oxide single crystal according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. In addition, in order to clearly explain the present invention, parts that are not related to the description are omitted in the drawings, and similar parts are designated by similar reference numerals throughout the specification.

[0027] Throughout the specification, when a part is said to be "connected" to another part, this includes not only the case where the part is "directly connected" to another part, but also the case where the part is "indirectly connected" to another part via another member or element in between. Furthermore, when a part is said to "include" a certain component, this does not exclude other components, and means that the part may further include other components, unless otherwise specified to the contrary.

[0028] The present invention will now be described in detail with reference to the accompanying drawings.

[0029] The powder for growing a gallium oxide single crystal according to an embodiment of the present invention is a raw material for manufacturing a gallium oxide single crystal ingot or substrate, and is composed of gallium oxide particles.

[0030] The gallium oxide particles may be composed of the (Alpha), (Beta), (Gamma), (Delta) or (Epsilon) phase. Preferably, the gallium oxide particles may be in the β phase.

[0031] The gallium oxide particles have an aspect ratio of 1 to 10. Preferably, they have an aspect ratio of 1 to 1.5.

[0032] The powder for growing gallium oxide single crystals according to one embodiment of the present invention is composed of gallium oxide particles having a low aspect ratio of 1 to 1.5, and therefore may be round in shape and have low cohesion.

[0033] The powder for growing gallium oxide single crystals according to an embodiment of the present invention may be composed of fine particles, specifically, fine particles having a D50 particle size of 20 μm or less.

[0034] Here, Dn particle size means the particle size at n% of the area cumulative distribution by particle size. For example, D50 is the particle size at 50% of the area cumulative distribution by particle size, and is called the median particle size. The above particle size can be measured using the laser diffraction method. Specifically, the powder to be measured is dispersed in a dispersion medium, and then introduced into a commercially available laser diffraction particle size measuring device. When the particles pass through a laser beam, the difference in the diffraction pattern due to the particle size is measured, and the particle size distribution is calculated.

[0035] The powder for growing gallium oxide single crystals according to one embodiment of the present invention has a predetermined bulk density or BET specific surface area.

[0036] Specifically, the powder for growing gallium oxide single crystals according to one embodiment of the present invention has a density of 0.7 g / cm 3 More than 1.0g / cm 3 It has the following bulk density:

[0037] In addition, the powder for growing gallium oxide single crystals according to one embodiment of the present invention has a diameter of 1.5 m 2 / g or more 4.0m 2 / g or less BET specific surface area,

[0038] Since the powder for growing gallium oxide single crystals according to an embodiment of the present invention has a bulk density or BET specific surface area within the above-mentioned range, it has an excellent raw material-crystal conversion rate during the growth of gallium oxide single crystals, and can grow a large amount of gallium oxide single crystals compared to the amount filled in the crucible. A detailed description of this will be given later.

[0039] Hereinafter, a method for producing a powder for growing a gallium oxide single crystal according to an embodiment of the present invention will be described with reference to FIG.

[0040] FIG. 1 is a flow chart for explaining a method for producing a powder for growing a gallium oxide single crystal according to one embodiment of the present invention.

[0041] Referring to FIG. 1, a method for producing a powder for growing a gallium oxide single crystal according to an embodiment of the present invention is produced by thermal vaporized synthesis.

[0042] Specifically, gallium is heated and vaporized (S110).

[0043] First, solid gallium is provided in the reactor, where the gallium metal can be provided in the form of plates or particles.

[0044] Next, the reactor is heated so that the solid gallium is vaporized. For example, the reactor can be heated at a temperature of 1,000°C to 1,600°C. The solid gallium is vaporized within the above-mentioned range, and the vaporized gallium droplets can float in the reactor.

[0045] The vaporized gallium is then oxidized (S120).

[0046] Specifically, oxygen (O2) is supplied into the reactor to oxidize the vaporized gallium. The oxygen can be supplied at a flow rate of 0.5 to 70 m / sec. When oxygen is supplied at the above flow rate, the vaporized gallium reacts with the oxygen and is oxidized to form gallium oxide.

[0047] The oxidized gallium oxide is then cooled and crystallized (S130).

[0048] The cooling of the gallium oxide may be performed in a transfer pipe connected to the reactor. For example, as oxygen flows into the reactor, the pressure in the reactor increases, and the compressed gas flows into the transfer pipe with a relatively low pressure, and the gallium oxide may flow into the transfer pipe together.

[0049] Gallium oxide can be rapidly cooled in a transfer pipe by natural cooling. By rapidly cooling gallium oxide, rapid crystallization occurs, and it can be crystallized into round particles with an aspect ratio of 1 to 1.5.

[0050] Thereafter, the crystallized gallium oxide is collected to obtain gallium oxide powder (S140).

[0051] The gallium oxide particles crystallized while moving through the transfer pipe are accumulated in a collector connected to the transfer pipe and can be obtained in powder form. In this case, the collector can be maintained at a low pressure so that the gallium oxide particles can be collected in the collector.

[0052] The gallium oxide particles collected by the collection unit may be composed of fine particles of 200 nm or less, for example, the D50 particle size of the gallium oxide particles may be 100 to 150 nm.

[0053] The bulk density of the obtained gallium oxide powder was then adjusted to 0.7 g / cm 3 More than 1.0g / cm 3 Densification (S150) is performed so that:

[0054] The densification process may refer to a step of adjusting the bulk density or BET specific surface area of ​​gallium oxide so that the obtained gallium oxide powder has an excellent raw material-to-crystal conversion rate.

[0055] Specifically, the bulk density of the gallium oxide powder was increased to 0.7 g / cm by heat treatment of the obtained gallium oxide powder. 3 More than 1.0g / cm 3 It can be processed as follows:

[0056] The above-mentioned heat treatment can be carried out by heating after charging gallium oxide powder into a crucible made of a material having high heat resistance and high fire resistance.In this case, the crucible may be made of alumina, but is not limited thereto, and is not particularly limited as long as it is made of a material having high heat resistance and high fire resistance.

[0057] The heat treatment may be carried out at a temperature of 1,200° C. to 1,300° C. for 5 hours or more, including the heating time.

[0058] If the heat treatment is carried out at a temperature below 1,200°C, the bulk density is 0.7 g / cm 3 If heat treatment is performed at temperatures above 1,300°C, the bulk density may be less than 1.0 g / cm 3 In addition, the bulk density may exceed 0.7 g / cm 3 Lower or 1.0g / cm 3 If the temperature exceeds 100° C., the raw material-to-crystal conversion rate of growing a gallium oxide single crystal from the gallium oxide powder may decrease, as will be described in detail below.

[0059] The heat treatment may be performed at normal pressure, but is not limited thereto, and may be performed at high pressure. In this case, hot isostatic processing (HIP) may be used, which is applied uniformly from all directions to the gallium oxide powder.

[0060] By carrying out the above-mentioned heat treatment, the powder for growing gallium oxide single crystals can have a BET specific surface area in a predetermined range. For example, 2 / g or more 4.0m 2 It is possible to obtain a powder for growing gallium oxide single crystals having a BET specific surface area of ​​0.1 μm or less.

[0061] In addition, the size of gallium oxide particles can be changed by carrying out the above-mentioned heat treatment. For example, the powder for growing gallium oxide single crystals after the heat treatment may be composed of particles with a D50 particle size of 20 μm or less. However, despite the heat treatment, the aspect ratio of the gallium oxide particles can be maintained at a ratio of 1 to 1.5.

[0062] As described above, the powder for growing gallium oxide single crystals according to an embodiment of the present invention has a specific bulk density and BET specific surface area. In addition, the powder for growing gallium oxide single crystals according to an embodiment of the present invention is characterized in that it is composed of gallium oxide particles having a round shape of 1 to 1.5 and has a D50 particle size of 20 μm or less. The powder for growing gallium oxide single crystals having the above-mentioned characteristics can have an excellent raw material-crystal conversion rate.

[0063] The present invention will now be described in detail with reference to experimental examples.

[0064] However, the following experimental examples are merely illustrative of the present invention, and the content of the present invention is not limited to the following examples.

[0065] First, in order to measure the single crystal conversion rate of the powder for growing a gallium oxide single crystal according to an embodiment of the present invention, a powder for growing a gallium oxide single crystal was prepared according to the following preparation example.

[0066] <Production Example>

[0067] First, solid metallic gallium was heated to a temperature of 1,000°C, and air was injected at a flow rate of 50 m / sec to induce oxidation, and then crystallization was induced through natural cooling to obtain the gallium oxide powder of Example 1.

[0068] As a control group (comparative example) for the above-mentioned Example 1, a commercially available gallium oxide powder from Lumi-m Company, China was prepared.

[0069] <Experimental Example 1> Comparison of particle characteristics before and after heat treatment

[0070] In order to compare the particle morphology characteristics of the gallium oxide powder according to Example 1 and the gallium oxide powder according to the Comparative Example, each powder was photographed using a scanning electron microscope (SEM).

[0071] FIG. 2 is a scanning electron microscope (SEM) photograph for comparing the particle morphology characteristics of powder before heat treatment in a method for producing a powder for growing a gallium oxide single crystal according to an embodiment of the present invention.

[0072] Referring to Example 1 in FIG. 2, it can be seen that the powder for growing gallium oxide single crystals according to one embodiment of the present invention is composed of round fine particles with a low aspect ratio before heat treatment, and the primary particles are not aggregated and are uniformly dispersed.

[0073] In addition, referring to the comparative example in FIG. 2, it can be seen that general gallium oxide powder is composed of acicular particles with a large aspect ratio, and exists in the form of secondary particles formed by aggregation of primary particles.

[0074] Specifically, the average particle size of the comparative example was measured to be 5.38 μm, and the average particle size of Example 1 was measured to be 0.67 μm, which indicates that the average particle size of Example 1 is at 1 / 10 of that of the comparative example. Also, the median particle size of the comparative example was measured to be 1.81 μm, and the median particle size of Example 1 was measured to be 0.13 μm, which indicates that the median particle size is also at 1 / 10 of that of the comparative example.

[0075] This is believed to be because the powder for growing gallium oxide single crystals according to one embodiment of the present invention is manufactured by a vaporization method. Compared to general powder for growing gallium oxide single crystals manufactured by a wet method, it has a lower aspect ratio and particle aggregation is suppressed.

[0076] <Experimental Example 2> Comparison of particle characteristics after heat treatment

[0077] The gallium oxide powder of Example 1 was heat-treated at the temperatures shown in Table 1 below to obtain powders for growing gallium oxide single crystals of Examples 2-2 to 2-8. The powder for growing gallium oxide single crystals of Example 2-1 was not heat-treated, i.e., it means the powder for growing gallium oxide single crystals of Example 1.

[0078] The heat treatment was performed in an alumina crucible by increasing the temperature of the crucible at a rate of 5° C. / min, maintaining the heat treatment temperature for a predetermined time, and then naturally cooling. In this case, the total time for maintaining the temperature from the time of temperature increase to the time after the heat treatment temperature was reached was always 5 hours.

[0079] [Table 1]

[0080] FIG. 3 is a SEM photograph of a powder for growing gallium oxide single crystals according to an embodiment obtained by heat-treating the gallium oxide powder according to Example 1 of FIG.

[0081] Specifically, FIG. 3 is an SEM photograph of the powders for growing gallium oxide single crystals of Examples 2-1, 2-2, 2-3, 2-4, and 2-8.

[0082] As is clear from FIG. 3, the powder for growing gallium oxide single crystals according to one embodiment of the present invention maintains almost all of its low aspect ratio characteristics compared to the gallium oxide powder before heat treatment (Example 2-1), and aggregation is significantly suppressed even after heat treatment.

[0083] In particular, referring to Examples 2-2 to 2-8, it can be seen that the particle characteristics before the heat treatment are well maintained despite the heat treatment. It can also be seen that the particle size increases as the heat treatment temperature increases, which is believed to be caused by the crystal growth of some particles due to the heat.

[0084] The particle size of the particles in Examples 2-1 to 2-8 was measured using a particle size analyzer (PSA) Mastersizer 2000 manufactured by Malvern, Inc. The results are shown in Table 2 below.

[0085] [Table 2]

[0086] As is clear from Table 2, as the heat treatment temperature increases, the particle size generally increases.

[0087] As is clear from Examples 2-4 to 2-7, the D50 particle size is 11.875 μm to 19.547 μm during heat treatment at temperatures of 1,200° C. to 1,300° C., and it is found that the D50 particle size is maintained within 20 μm even after heat treatment.

[0088] <Experimental Example 3> Measurement of raw material-crystal conversion rate

[0089] The powder for growing gallium oxide single crystals according to one embodiment of the present invention has a bulk density or BET specific surface area within a specific range, and the powder for growing gallium oxide single crystals having the above-mentioned characteristics has an excellent raw material-crystal conversion rate.

[0090] In order to analyze the relationship between the characteristics of the bulk density or BET specific surface area of ​​the powder for growing gallium oxide single crystals according to one embodiment of the present invention and the raw material-crystal conversion rate, first, the bulk density and BET specific surface area of ​​the powders of Examples 2-1 to 2-8 were measured.

[0091] The bulk density was calculated by filling a crucible with the powder according to the example until the crucible was filled to capacity, and then dividing the weight of the powder by the internal volume of the crucible.

[0092] The BET specific surface area was measured according to ASTM D 3663 using a Tristar II instrument from Micrometrics.

[0093] In order to measure the raw material-crystal conversion rate of Examples 2-1 to 2-8, gallium oxide single crystals were grown using the powders of Examples 2-1 to 2-8.

[0094] The gallium oxide single crystal growth powder according to an embodiment of the present invention can be processed into a single crystal ingot (or substrate) using various growth methods, such as the Czochralski method, the floating zone method, the Bridgman method, the Vertical Bridgman method (VB), and the Edge-defined Film-fed Growth (EFG) method.

[0095] In this specification, as an example, a method for producing a gallium oxide single crystal by the EFG method will be described with reference to Fig. 4. However, the powder for growing a gallium oxide single crystal according to an embodiment of the present invention is not only applicable to the EFG method, but can also be processed into a single crystal ingot using the various single crystal growth methods described above.

[0096] FIG. 4 is a conceptual diagram for explaining a method for growing a gallium oxide single crystal using a powder for growing a gallium oxide single crystal according to one embodiment of the present invention.

[0097] Referring to FIG. 4 , the EFG apparatus includes a crucible 210 that provides a space for melting powder for growing gallium oxide single crystals, a heater 220 that surrounds the crucible 210, a mold 231 that is disposed in the center of the crucible 210, and a slit 235 that is the internal space of the mold 231 and communicates with the internal space of the crucible 210.

[0098] The crucible 210 may be made of a highly heat-resistant material that has excellent thermal conductivity and does not deform or melt even at the melting point of gallium oxide, and may be made of, for example, iridium.

[0099] The heater 220 is a member capable of heating the crucible 210, and may be configured, for example, as a coil that generates heat in the crucible 210 using induced electromotive force. However, the heater 220 is not limited thereto, and may be configured to directly generate heat in a resistive manner.

[0100] The mold 231 constitutes the outer wall of the slit 235, and can be formed with an appropriate thickness so as to prevent leakage or evaporation of the gallium oxide melt M that has risen to the slit 235. The mold 231 may be made of the same material as the crucible 210.

[0101] The slit 235 allows the gallium oxide melt M to rise and induce the growth of a single crystal, and the cross-sectional shape of the slit 235 can correspond to the cross-sectional shape of the gallium oxide single crystal ingot S that will be finally formed.

[0102] The powder for growing the gallium oxide single crystal is charged into the internal space of the crucible 210, and when the crucible 210 is heated by the heater 220, it melts and a gallium oxide melt M can be formed.

[0103] In this experimental example, 150 g of each of the powders for growing gallium oxide single crystals of Examples 2-1 to 2-8 was melted at a temperature of 1,800° C. or higher using an iridium crucible.

[0104] The gallium oxide melt M can rise by capillary force to the slit 235 communicating with the internal space of the crucible 210. The gallium oxide melt M that has risen to the upper end of the slit 235 by capillary force comes into contact with a seed crystal that starts the growth of a single crystal, and grows along the direction in which the seed crystal rises, thereby forming a gallium oxide single crystal ingot S.

[0105] In this experimental example, a gallium oxide single crystal was grown in the b-axis direction using a β-Ga2O3 seed crystal.

[0106] Furthermore, the raw material-crystal conversion rate was measured for Examples 2-1 to 2-8. The single crystal conversion rate was calculated by the following Equation 1.

[0107]

number

[0108] The experimental results for Examples 2-1 to 2-8 are shown in Table 3 below.

[0109] [Table 3]

[0110] Referring to Table 3, the powders for growing gallium oxide single crystals in Examples 2-4 to 2-7 had a density of 0.7 to 1.0 g / cm 3 It has a bulk density of 1.5 to 4.0 m 2 / g BET specific surface area.

[0111] It can be seen that the powders for growing gallium oxide single crystals of Examples 2-4 to 2-7 have a superior raw material-crystal conversion rate compared to the powders for growing gallium oxide single crystals of Examples 2-1 to 2-3 and 2-8. That is, it can be seen that of the 150 g of powder charged into the crucible, 87% or more of the raw material grew into a gallium oxide single crystal. In particular, it can be seen that the raw material-crystal conversion rate was improved by 15% or more compared to the powder for growing gallium oxide single crystals of Example 2-1 that was not heat-treated.

[0112] The inventors of the present invention have discovered that when a powder for growing gallium oxide single crystals has a specific bulk density or a specific BET specific surface area, the powder packing rate can be maximized and at the same time the raw material-crystal conversion rate can be maximized.

[0113] That is, the bulk density of the powder for growing gallium oxide single crystals is 0.7 to 1.0 g / cm 3 The BET specific surface area is 1.5 to 4.0 m 2 / g, a large amount of powder can be loaded into the crucible and the raw material-to-crystal conversion rate can be maximized.

[0114] If the bulk density is 0.7 g / cm 3 If it is less than this, the crucible may not be filled with a sufficiently large amount of powder for growing gallium oxide single crystals, which may result in a reduced raw material-to-crystal conversion rate.

[0115] In addition, the bulk density is 1.0 g / cm 3 If it exceeds 100%, the crucible can be filled with a sufficiently large amount of powder for growing gallium oxide single crystals, but the BET specific surface area is too low, and the powder for growing gallium oxide single crystals may not melt sufficiently. Therefore, the melting uniformity may decrease, and gallium oxide crystallization may be hindered. This may decrease the raw material-crystal conversion rate.

[0116] In addition, the powder for growing gallium oxide single crystals according to one embodiment of the present invention is characterized by having an aspect ratio of 1 to 1.5 and being composed of particles with a D50 of 20 μm or less, so that it can satisfy the bulk density and BET specific surface area in the above-mentioned ranges, thereby having an excellent raw material-to-crystal conversion rate.

[0117] The above description of the present invention is for illustrative purposes only, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. Therefore, the above-described embodiments should be understood to be illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed form, and similarly, each component described as a distributed type may be implemented in a combined form.

[0118] The scope of the present invention is indicated by the claims set forth below rather than the above detailed description, and all modifications and variations derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

Claims

1. A powder for growing gallium oxide single crystals, which is made of gallium oxide and has a bulk density of 0.7 g / cm ３ 1.0g / cm or more ３ or less, and a BET specific surface area of ​​1.5 m 2 / g or more and 4.0 m 2 / g or less.

2. The powder for growing gallium oxide single crystals according to claim 1, wherein the powder for growing gallium oxide single crystals is composed of gallium oxide particles having a D50 particle size of 20 μm or less.

3. The powder for growing gallium oxide single crystals according to claim 2, wherein the aspect ratio of the gallium oxide particles is 1 to 1.

5.

4. The powder for growing gallium oxide single crystals according to claim 2 , wherein the gallium oxide particles are gallium oxide.

5. a vaporization step in which gallium is heated and vaporized; an oxidation step of oxidizing the vaporized gallium; a crystallization step of cooling and crystallizing the oxidized gallium oxide; A collection step of collecting the crystallized gallium oxide to obtain gallium oxide powder; The bulk density of the collected gallium oxide powder was 0.7 g / cm ３ 1.0g / cm or more ３ A method for producing a powder for growing gallium oxide single crystals, comprising:

6. The densification step comprises: The method for producing a powder for growing a gallium oxide single crystal according to claim 5, comprising a heat treatment step of heat treating the gallium oxide powder at a temperature of 1,200 ° C. to 1,300 ° C.

7. The method of claim 6, wherein the heat treatment is performed for 5 hours or more.

8. The powder for growing gallium oxide single crystals has a BET specific surface area of ​​1.5 m ２ / g or more 4.0m ２ The method for producing a powder for growing a gallium oxide single crystal according to claim 5, wherein the average molecular weight of the powder is 1.0 to 1.0 g.

9. The method for producing a powder for growing a gallium oxide single crystal according to claim 5, wherein the powder for growing a gallium oxide single crystal is composed of gallium oxide particles having a D50 particle size of 20 μm or less.

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