Preparation method of high-purity gallium oxide polycrystal

Abstract

The invention relates to the technical field of preparation of gallium oxide, in particular to a preparation method of high-purity gallium oxide polycrystal, which comprises the following steps of: briquetting and forming gallium oxide to obtain a gallium oxide charge bar; carrying out high-temperature calcination on the gallium oxide charge bar to obtain a gallium oxide crude body; and transferring the cooled gallium oxide crude body to a plasma melting furnace for high-temperature plasma melting, then carrying out vacuum impurity removal, and cooling to obtain the blocky high-purity gallium oxide polycrystal. According to the method, the gallium oxide crude body is subjected to high-temperature plasma melting, then vacuum impurity removal and cooling are carried out, the high-purity gallium oxide polycrystal is obtained, the purity of the gallium oxide polycrystal is guaranteed, and the requirement of a semiconductor material is met.

Description

Technical Field

[0001] The invention relates to the technical field of gallium oxide preparation, and in particular to a method for preparing high-purity gallium oxide polycrystal. Background Art

[0002] Gallium oxide (Ga2O3) is a wide bandgap semiconductor with Eg = 4.9eV. Its conductivity and luminescence properties have long attracted people's attention. Ga2O3 is a transparent oxide semiconductor material with broad application prospects in optoelectronic devices. It is used as an insulating layer for Ga-based semiconductor materials and as an ultraviolet filter. It can also be used as an O2 chemical detector.

[0003] After searching, the Chinese patent publication number CN110937622A discloses a method for preparing 4N gallium oxide from sponge gallium, including acid dissolving sponge gallium, diluting and filtering to obtain a gallium salt solution; adding a preprecipitant to the gallium salt solution to form a colloidal precipitate, and separating the solid and liquid to obtain a high-purity gallium salt solution; the high-purity gallium salt solution reacts with the precipitant to obtain a gallium oxide hydrate precipitate; washing, drying, roasting, and cooling the gallium oxide hydrate precipitate to obtain 4N grade high-purity gallium oxide. The above patent has the following shortcomings: the purity of the obtained gallium oxide is low and cannot meet the needs of semiconductor materials. In view of this, we propose a method for preparing high-purity gallium oxide polycrystals. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing high-purity gallium oxide polycrystals, so as to improve the purity of gallium oxide polycrystals by subjecting gallium oxide crude to high-temperature plasma melting and then vacuum impurity removal, and to recycle waste water in the preparation process.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for preparing high-purity gallium oxide polycrystal comprises the following steps:

[0007] Step 1, forming gallium oxide blocks to obtain gallium oxide rods;

[0008] Step 2, calcining the gallium oxide rod at high temperature to obtain a rough gallium oxide;

[0009] Step 3: Transfer the cooled gallium oxide bulk to a plasma melting furnace for high-temperature plasma melting, and then perform vacuum impurity removal and cooling to obtain bulk high-purity gallium oxide polycrystals.

[0010] Preferably, in step 1, the gallium oxide is 4N or higher gallium oxide.

[0011] Preferably, in step 1, the step of pressing blocks comprises: placing gallium oxide in a mold, and cold pressing the blocks by a cold isostatic press, wherein the cold pressing pressure is 240 to 270 MPa, and the holding time is 5 to 20 min.

[0012] Preferably, in step 2, the high temperature calcination temperature is 800 to 1200° C., and the high temperature calcination time is 2 to 8 hours.

[0013] Preferably, in step 3, the high temperature plasma temperature is 2000-2500° C., and the working gas is any one of argon and nitrogen.

[0014] Preferably, in step 3, the plasma melting furnace needs to be preheated before use, and the preheating temperature is 100-150° C. to remove moisture in the furnace.

[0015] Preferably, in step 3, the cooling is performed by a gradient program, and the cooling rate is 2 to 8°C / min.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The preparation method of high-purity gallium oxide polycrystals uses gallium oxide with a purity of 4N or above as a raw material, obtains gallium oxide rough bodies through block forming and high-temperature calcination, transfers the gallium oxide rough bodies to a plasma melting furnace for high-temperature plasma melting, and then performs vacuum impurity removal and cooling to obtain high-purity gallium oxide polycrystals. Under vacuum conditions, impurities in liquid gallium oxide rapidly volatilize or sublimate due to reduced partial pressure, making it easier for impurities to escape from the liquid gallium oxide. At the same time, the vacuum environment can also reduce pollution such as oxygen, thereby ensuring the purity of the gallium oxide polycrystals and meeting the needs of semiconductor materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The present invention is a flow chart of the method for preparing high-purity gallium oxide polycrystals. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1

[0021] A method for preparing high-purity gallium oxide polycrystal comprises the following steps:

[0022] Step 1, placing 4N gallium oxide in a mold, and cold pressing it by a cold isostatic press, the cold pressing pressure is 240-270 MPa, and the holding time is 5-20 min, to obtain a gallium oxide material rod;

[0023] Step 2, calcining the gallium oxide rod at a high temperature of 800° C. for 8 hours to obtain a rough gallium oxide;

[0024] Step 3: Transfer the cooled gallium oxide bulk to a plasma melting furnace for high-temperature plasma melting. The high-temperature plasma temperature is 2000°C, and the working gas is argon. The plasma melting furnace needs to be preheated before use. The preheating temperature is 100°C to remove moisture in the furnace. Then vacuum impurities are removed and the temperature is lowered. The cooling is performed using a gradient program with a cooling rate of 8°C / min to obtain block-shaped high-purity gallium oxide polycrystals above 6N.

[0025] Example 2

[0026] A method for preparing high-purity gallium oxide polycrystal comprises the following steps:

[0027] Step 1, placing 4N gallium oxide in a mold, and cold pressing it by a cold isostatic press, the cold pressing pressure is 240-270 MPa, and the holding time is 5-20 min, to obtain a gallium oxide material rod;

[0028] Step 2, calcining the gallium oxide rod at a high temperature of 900° C. for 6 hours to obtain a rough gallium oxide;

[0029] Step 3: Transfer the cooled gallium oxide bulk to a plasma melting furnace for high-temperature plasma melting. The high-temperature plasma temperature is 2100°C, and the working gas is argon. The plasma melting furnace needs to be preheated before use. The preheating temperature is 110°C to remove moisture in the furnace. Then vacuum impurities are removed and the temperature is lowered. The cooling is performed using a gradient program with a cooling rate of 4°C / min to obtain block-shaped high-purity gallium oxide polycrystals above 6N.

[0030] Example 3

[0031] Step 1, placing 4N gallium oxide in a mold, and cold pressing it by a cold isostatic press, the cold pressing pressure is 240-270 MPa, and the holding time is 5-20 min, to obtain a gallium oxide material rod;

[0032] Step 2, calcining the gallium oxide rod at a high temperature of 1000° C. for 4 hours to obtain a rough gallium oxide;

[0033] Step 3: Transfer the cooled gallium oxide bulk to a plasma melting furnace for high-temperature plasma melting. The high-temperature plasma temperature is 2300°C, and the working gas is nitrogen. The plasma melting furnace needs to be preheated before use. The preheating temperature is 130°C to remove moisture in the furnace. Then vacuum impurities are removed and the temperature is lowered. The cooling is performed using a gradient program with a cooling rate of 6°C / min to obtain block-shaped high-purity gallium oxide polycrystals above 6N.

[0034] Example 4

[0035] A method for preparing high-purity gallium oxide polycrystal comprises the following steps:

[0036] Step 1, placing 4N gallium oxide in a mold, and cold pressing it by a cold isostatic press, the cold pressing pressure is 240-270 MPa, and the holding time is 5-20 min, to obtain a gallium oxide material rod;

[0037] Step 2, calcining the gallium oxide rod at a high temperature of 1200° C. for 2 h to obtain a rough gallium oxide;

[0038] Step 3: Transfer the cooled gallium oxide bulk to a plasma melting furnace for high-temperature plasma melting. The high-temperature plasma temperature is 2500°C, and the working gas is nitrogen. The plasma melting furnace needs to be preheated before use. The preheating temperature is 150°C to remove moisture in the furnace. Then vacuum impurities are removed and the temperature is lowered. The cooling is performed using a gradient program with a cooling rate of 8°C / min to obtain block-shaped high-purity gallium oxide polycrystals above 6N.

[0039] The preparation method of high-purity gallium oxide polycrystal of the present invention uses gallium oxide with a purity of 4N or above as raw material, obtains gallium oxide rough body by block forming and high-temperature calcination, transfers the gallium oxide rough body to a plasma melting furnace for high-temperature plasma melting, then vacuum removes impurities, and cools to obtain high-purity gallium oxide polycrystal. Under vacuum conditions, impurities in liquid gallium oxide rapidly volatilize or sublimate due to reduced partial pressure, making it easier for impurities to escape from the liquid gallium oxide. At the same time, the vacuum environment can also reduce pollution such as oxygen, thereby ensuring the purity of the gallium oxide polycrystal and meeting the needs of semiconductor materials.

[0040] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing high-purity gallium oxide polycrystals, characterized in that: The following steps are involved: Step 1, forming gallium oxide blocks to obtain gallium oxide rods; Step 2, calcining the gallium oxide rod at high temperature to obtain a rough gallium oxide; Step 3: Transfer the cooled gallium oxide bulk to a plasma melting furnace for high-temperature plasma melting, and then perform vacuum impurity removal and cooling to obtain bulk high-purity gallium oxide polycrystals.

2. The method for preparing high-purity gallium oxide polycrystal according to claim 1, characterized in that: In the step 1, the gallium oxide is 4N or higher gallium oxide.

3. The method for preparing high-purity gallium oxide polycrystal according to claim 1, characterized in that: In step 1, the step of pressing blocks comprises: placing gallium oxide in a mold, and cold pressing the blocks by a cold isostatic press, wherein the cold pressing pressure is 240 to 270 MPa, and the holding time is 5 to 20 minutes.

4. The method for preparing high-purity gallium oxide polycrystal according to claim 1, characterized in that: In the step 2, the high temperature calcination temperature is 800 to 1200° C., and the high temperature calcination time is 2 to 8 hours.

5. The method for preparing high-purity gallium oxide polycrystal according to claim 1, characterized in that: In step 3, the high temperature plasma temperature is 2000-2500° C., and the working gas is any one of argon and nitrogen.

6. The method for preparing high-purity gallium oxide polycrystal according to claim 1, characterized in that: In step 3, the plasma melting furnace needs to be preheated before use, and the preheating temperature is 100-150° C. to remove moisture in the furnace.

7. The method for preparing high-purity gallium oxide polycrystal according to claim 1, characterized in that: In the step 3, the cooling is performed by a gradient program, and the cooling rate is 2 to 8°C / min.

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