阅读说明：本技术 一种靶材级氧化镓的制备方法 (Preparation method of target-grade gallium oxide ) 是由 康冶 王波 朱刘 于 2020-05-21 设计创作，主要内容包括：本发明涉及一种靶材级氧化镓的制备方法,属于半导体材料技术领域。本发明通过将A溶液和B溶液同时加入底液C溶液中,同时限定反应温度、A溶液和B溶液的浓度、A溶液和B溶液的加料速度、沉淀剂的种类,制备得到椭球形、粒度D50＝1.5～2μm的氧化镓。本发明制备得到的氧化镓较棒状氧化镓具有较高的流动性和分散性,以满足靶材使用。且本发明制备得到的氧化镓具有以下特点：高比表面积,BET＝10～15g/cm<Sup>2</Sup>；纯度高,可以达到99.995％；粒度小,D50＝1.5～2μm。(The invention relates to a preparation method of target-grade gallium oxide, belonging to the technical field of semiconductor materials. According to the invention, the solution A and the solution B are simultaneously added into the solution C of the base solution, and the reaction temperature, the concentrations of the solution A and the solution B, the feeding speeds of the solution A and the solution B and the types of the precipitating agents are simultaneously limited, so that the gallium oxide which is ellipsoidal and has the particle size D50 of 1.5-2 mu m is prepared. The gallium oxide prepared by the invention has higher fluidity and dispersibility than rod-shaped gallium oxide so as to meet the use requirement of a target material. The gallium oxide prepared by the invention has the following characteristics: high specific surface area, BET is 10-15 g/cm 2 (ii) a The purity is high and can reach 99.995%; the particle size is small, and D50 is 1.5-2 μm.)

1. A preparation method of target-grade gallium oxide is characterized by comprising the following steps:

(1) preparing solution A: preparing a gallium nitrate solution, diluting the gallium nitrate solution until the content of gallium is 25-55 g/L and the concentration of free nitric acid is 0.1% -10%, and then adding a surfactant to obtain a solution A;

(2) b, preparing a solution: preparing a precipitator into a solution with the mass fraction of 5-15% to obtain a solution B;

(3) preparing a base solution: adding the solution B into pure water to prepare a base solution C;

(4) precipitation reaction: simultaneously adding the solution A and the solution B into the solution C of the base solution to carry out precipitation reaction;

(5) and then carrying out aging reaction, centrifugal washing and calcination to obtain the target-grade gallium oxide.

2. The method according to claim 1, wherein in the step (1), the gallium nitrate solution is prepared by: heating the solvent, adding gallium metal and stirring; then adding nitric acid, stirring and reacting to obtain gallium nitrate solution.

3. The preparation method according to claim 2, wherein the mass ratio of the metal gallium to the surfactant is (20-200): 1.

4. the method according to claim 1, wherein in the step (1), the surfactant is at least one of dodecylbenzene sulfonic acid, sodium alkylbenzenesulfonate, α -olefin sulfonate, and secondary sodium alkylsulfonate.

5. The method according to claim 1, wherein in the step (2), the precipitant is at least one of ammonia water, ammonium bicarbonate and sodium hydroxide.

6. The method according to claim 1, wherein in the step (3), the temperature of the solution C is 40 to 70 ℃, and the pH of the solution C is 7.5 to 9.5.

7. The preparation method according to claim 1, wherein in the step (4), the reaction temperature is 40-70 ℃, the volume ratio of the solution of the base solution C to the solution A is 1 (0.5-1.5), the feeding speed of the solution A is 1-20L/min, the pH value of the system is maintained at 7.5-9.5 by regulating the feeding speed of the solution B, the stirring is continued for 1-3 h after the feeding is finished, the temperature in the stirring process is 40-70 ℃, and the pH value is 7.5-9.5.

8. The method according to claim 1, wherein in the step (5), the aging reaction is carried out at a temperature of 75 to 95 ℃ and a pH of 7.5 to 9.5 for 1 to 8 hours.

9. The production method according to claim 1, wherein in the step (5), washing is carried out until the washing water conductivity is less than 100. mu.S/cm.

10. The method according to claim 1, wherein in the step (5), the calcining temperature is 600 to 900 ℃ and the calcining time is 4 to 12 hours.

Technical Field

The invention relates to a preparation method of target-grade gallium oxide, belonging to the technical field of semiconductor materials.

Background

Gallium oxide (Ga)₂O₃) Is an important wide bandgap semiconductor material with five crystal structures of α -Ga₂O₃、β-Ga₂O₃、γ-Ga₂O₃、-Ga₂O₃and-Ga₂O₃Which can be converted into each other under certain conditions β -Ga₂O₃Is most stable and has a monoclinic structure at room temperature, and the spatial structure is C2m， β＝103.83°。Ga₂O₃Has excellent photoluminescence performance, chemical and thermal stability and other characteristics, and may be used widely in sensitive material, catalyst, photoelectronic material, fluorescent powder and other fields.

In recent years, IGZO (indium gallium zinc oxide) is applied to the field of TFT-LCD displays, so that the number of transistors is reduced, the light transmittance of each pixel is improved, and the display has a higher energy efficiency level and higher efficiency. At present, a radio frequency/direct current (RF/DC) sputtering system is the mainstream film growth equipment, and factors influencing the quality of the sputtered transparent conductive film play a crucial role in the density, conductivity, grain size, microstructure and purity of the target besides the film deposition process. For example, the target material has low density, that is, micropores are formed on the surface or inside of the target material, and during the coating process, protrusions appear on the surface of the target material, which causes the local energy of the target material to be too high, and oxygen ions are impacted into a free state to form a high resistance region, which causes some microparticles to enter the film, thereby reducing the quality of the film and affecting the stability of the coating.

Currently, IGZO sputtering target materials sold In commercial markets are mainly sintered by solid-phase reaction hot pressing, and In is prepared by₂O₃ZnO and Ga₂O₃Mixing the three kinds of powder according to a certain proportion, ball-milling and homogenizing, hot-pressing and sintering and the like to prepare the IGZO target material for sputtering. The preparation method is simple to operate, but the uniformity of mechanical ball milling mixing is influenced by the granularity and the morphology of each powder. In₂O₃ZnO and Ga₂O₃The granularity, the shape, the fluidity and the dispersity of the powder play a decisive role in the homogenizing effect and the hot pressing process.

Chinese patent application CN108821329A discloses a method for preparing high purity gallium oxide, which comprises dissolving gallium metal in a mixed solution of sulfuric acid and hydrogen peroxide to obtain gallium sulfate solution, purifying by crystallization to obtain high purity gallium sulfate crystal, and calcining the sulfuric acid crystal to obtain high purity gallium oxide. Although the method can obtain high-purity gallium oxide, sulfur oxide-containing gas is generated in the calcining process, the obtained product is agglomerated, the uniformity of the crushed product is poor, the decomposition temperature of the sulfate is high, and the energy consumption is high.

Chinese patent application CN107010654B discloses a method for preparing monodisperse gallium oxide powder and its high-density ceramic target material. The invention uses more than 99.99% of metal gallium to dissolve in acid, then ammonia water is added for precipitation and aging to obtain white precipitate, and the product is obtained through procedures of washing, filtering, drying, calcining and the like. However, the method has high calcination temperature, the obtained product microscopic particles are easy to agglomerate, and the product uniformity is reduced.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a preparation method of target-grade gallium oxide.

In order to achieve the purpose, the invention adopts the technical scheme that: a preparation method of target-grade gallium oxide comprises the following steps:

(1) preparing solution A: preparing a gallium nitrate solution, diluting the gallium nitrate solution until the gallium content is 25-55 g/L (0.358-0.789 mol/L) and the concentration of free nitric acid is 0.1-10%, and then adding a surfactant to obtain a solution A;

(2) b, preparing a solution: preparing a precipitator into a solution with the mass fraction of 5-15% to obtain a solution B;

(3) preparing a base solution: adding the solution B into pure water to prepare a base solution C;

(4) precipitation reaction: simultaneously adding the solution A and the solution B into the solution C of the base solution to carry out precipitation reaction;

(5) and then carrying out aging reaction, centrifugal washing and calcination to obtain the target-grade gallium oxide.

At present, the method commonly adopted in the high-purity gallium oxide industry is to precipitate gallium ions with ammonia water to obtain hydroxyl gallium oxide, and then calcine the hydroxyl gallium oxide to obtain a gallium oxide product. However, the gallium oxide obtained by the method is rod-shaped, and the rod-shaped structure has poor fluidity and dispersibility, so that the uniformity and density of the target are influenced when the target is prepared.

The preparation method aims at synthesizing ellipsoidal gallium oxide with the granularity D50 of 1.5-2 mu m, and the method comprises the steps of simultaneously adding the solution A and the solution B into the solution C of the base solution, and simultaneously limiting the reaction temperature, the concentrations of the solution A and the solution B and the feeding speeds of the solution A and the solution B to obtain the granularity D50 of 1.5-2 mu m; the shape of the solution is ellipsoidal by limiting the types of the precipitating agents and the concentrations of the solution A and the solution B. The gallium oxide prepared by the invention has higher fluidity and dispersibility than rod-shaped gallium oxide so as to meet the use requirement of a target material. The gallium oxide prepared by the invention has the following characteristics: high specific surface area, BET is 10-15 g/cm²(ii) a The purity is high and can reach 99.995%; the particle size is small, and D50 is 1.5-2 μm.

As a preferred embodiment of the preparation method of the present invention, in the step (1), the preparation method of the gallium nitrate solution comprises: heating the solvent, adding gallium metal and stirring; then adding nitric acid, stirring and reacting to obtain gallium nitrate solution.

Preferably, in the step (1), the preparation method of the gallium nitrate solution comprises: adding solvent water into a reaction kettle, heating to above 30 ℃, adding metal gallium and stirring to disperse the metal gallium into a liquid drop shape; adding nitric acid into the reaction kettle, reacting at 40-80 ℃, continuously stirring until the reaction is finished, and filtering to remove unreacted solid impurities to obtain a gallium nitrate solution.

Preferably, the purity of the gallium metal is 99.999% and the molar ratio of gallium metal to nitric acid is 1: 4.

As a preferred embodiment of the preparation method, the mass ratio of the metal gallium to the surfactant is (20-200): 1.

as a preferred embodiment of the preparation method of the present invention, in the step (1), the surfactant is at least one of dodecylbenzene sulfonic acid (LAS), sodium Alkyl Benzene Sulfonate (ABS), alpha-olefin sulfonate (AOS), and secondary alkyl sodium sulfonate (SAS).

In a preferred embodiment of the preparation method of the present invention, in the step (2), the precipitant is at least one of ammonia water, ammonium bicarbonate and sodium hydroxide.

More preferably, the precipitant is at least one of ammonia water and sodium hydroxide, and the ellipsoidal gallium oxide can be formed by using the precipitant.

More preferably, the precipitant is ammonia water, and the ellipsoidal gallium oxide can be formed by using the precipitant, and the post-treatment operation is simple.

In the preferable embodiment of the preparation method of the present invention, in the step (3), the temperature of the solution of the base solution C is 40 to 70 ℃, and the pH of the solution of the base solution C is 7.5 to 9.5.

As a preferred embodiment of the preparation method, in the step (4), the reaction temperature is 40-70 ℃, the volume ratio of the solution of the base solution C to the solution A is 1 (0.5-1.5), the feeding speed of the solution A is 1-20L/min, the pH value of the system is maintained to be 7.5-9.5 by regulating the feeding speed of the solution B, the stirring is continued for 1-3 h after the feeding is finished, the temperature in the stirring process is 40-70 ℃, and the pH value is 7.5-9.5.

In the precipitation reaction, the volume ratio of the solution C as the base solution to the solution A is 1 (0.5-1.5), the dosage range of the solution B is not limited, and the pH value of the reaction system is maintained to be 7.5-9.5 by adjusting the speed of the solution B until the solution A is added.

And simultaneously adding the solution A and the solution B into the solution C of the base solution, and maintaining the pH value of the system to be 7.5-9.5 by regulating the feeding speed of the solution B to form a balanced reaction system, so that the control of granularity and morphology is facilitated. In the existing preparation method, the solution B is directly added into the solution A, the concentration of gallium ions is continuously changed, and the formed particles are different in size.

As a preferred embodiment of the preparation method, in the step (5), the temperature of the aging reaction is 75-95 ℃, the pH value is 7.5-9.5, and the time is 1-8 h.

As a preferable embodiment of the production method of the present invention, in the step (5), washing is performed until the washing water conductivity is less than 100. mu.S/cm.

As a preferred embodiment of the preparation method, in the step (5), the calcining temperature is 600-900 ℃ and the time is 4-12 h.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, the solution A and the solution B are simultaneously added into the solution C of the base solution, and the reaction temperature, the concentrations of the solution A and the solution B, the feeding speeds of the solution A and the solution B and the types of the precipitating agents are simultaneously limited, so that the gallium oxide which is ellipsoidal and has the particle size D50 of 1.5-2 mu m is prepared. The gallium oxide prepared by the invention has higher fluidity and dispersibility than rod-shaped gallium oxide so as to meet the use requirement of a target material. The gallium oxide prepared by the invention has the following characteristics: high specific surface area, BET is 10-15 g/cm²(ii) a The purity is high and can reach 99.995%; the particle size is small, and D50 is 1.5-2 μm.

Drawings

FIG. 1 is an SEM scanning electron micrograph of gallium oxide prepared according to example 1.

FIG. 2 is an SEM scanning electron micrograph of gallium oxide prepared according to example 2.

FIG. 3 is an SEM scanning electron micrograph of gallium oxide prepared according to example 3.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific examples.