CN113637941B

CN113637941B - Preparation method of zinc-gallium oxide magnetron sputtering target material

Info

Publication number: CN113637941B
Application number: CN202110799278.XA
Authority: CN
Inventors: 刘艺; 张训龙; 张锦
Original assignee: Anhui Jinhua Zinc Oxide Co ltd
Current assignee: Anhui Jinhua Zinc Oxide Co ltd
Priority date: 2021-07-15
Filing date: 2021-07-15
Publication date: 2023-03-28
Anticipated expiration: 2041-07-15
Also published as: CN113637941A

Abstract

The invention belongs to the technical field of zinc oxide materials, and particularly relates to a preparation method of a zinc-gallium oxide magnetron sputtering target material. In the past, organic binders are also used, zinc oxide powder is also physically and directly mixed, the zinc oxide powder cannot be mixed uniformly, local enrichment occurs, and the quality of prepared sputtering targets such as zinc oxide and the like is seriously influenced by the conventional mechanical powder mixing process because of the existence of larger air holes formed by decomposition of organic binders and uneven distribution of oxides. The method disclosed by the invention avoids the defects caused by the traditional method, and is suitable for magnetron sputtering target materials of zinc gallium oxide of films such as a functional dielectric layer for magnetron sputtering deposition of energy-saving Low-E glass, a transparent electrode layer of a thin-film solar cell and the like in powder metallurgy production.

Description

Preparation method of zinc-gallium oxide magnetron sputtering target material

Technical Field

The invention belongs to the technical field of zinc oxide materials, and particularly relates to a preparation method of a zinc gallium oxide magnetron sputtering target material.

Background

The third generation semiconductor material has the typical characteristics of wide forbidden band, high breakdown field strength, high exciton confinement energy and high saturated electron drift velocity, is widely applied in the fields of semiconductor illumination, next generation communication technology, energy internet, high-speed rail transit, power electronic devices, new energy devices and the like, and has become a new high competition for global strategy in the field of future semiconductor materials. Since 2016, china has set up a plurality of research projects in the special national key research and development plans of new energy vehicles, strategic advanced electronic materials, smart grid technologies and equipment and the like, and researches are carried out aiming at the key scientific problems of the foundation and the application of the third-generation semiconductor materials. The zinc oxide has a stable and rich low-dimensional structure, excellent room-temperature exciton stability and easy-doping-regulation electrical properties, and is unique in the third-generation semiconductor material system research. The zinc oxide has a non-centrosymmetric structure formed by cations and anions, so that piezoelectric potential generated under the action of external force is coupled with the transport performance of a semiconductor thereof, and the piezoelectric electronic effect for regulating the transport performance of a transistor by taking strain as a gate and the piezoelectric optoelectronic effect for regulating the photoelectric response of a heterojunction can be realized. The method successfully establishes effective connection between strain and interface carrier transport behavior regulation and control, and opens up a brand-new research field from the aspects of device construction, performance regulation and control and the like. In the research field of light-emitting devices, the end face and the side face of zinc oxide of a hexagonal wurtzite structure and optical feedback formed by random scattering enable low-dimensional zinc oxide to have the structural characteristics of a natural resonant cavity, laser emission of various oscillation modes can be obtained, how to realize effective regulation of the oscillation modes and high-efficiency output of single-mode laser is the main challenge facing practical application of a zinc oxide laser, in the research aspect of a transparent conductive film, the visible-near infrared band transmittance of the zinc oxide exceeds 90%, and the zinc oxide material has the characteristics of easy etching, strong radiation resistance, strong process compatibility with a photoelectric device and the like, so that the zinc oxide material becomes an important candidate material for replacing Indium Tin Oxide (ITO). How to obtain a high-quality zinc oxide film with high conductivity and high light transmittance through effective doping is an important development direction in the field. Achieving stable p-type zinc oxide is a recognized international problem, and nitrogen doping is still considered to be an effective way to solve this problem. The deep understanding of the function relationship between the intrinsic defect structure of zinc oxide and the doping atoms has important scientific significance for promoting the p-type doping problem of zinc oxide. For example, chinese patent CN2015107644216 discloses the use of a dispersant; the dispersant is at least one of polyvinyl alcohol, polycarboxylate, polyacrylate or carboxymethyl cellulose salt, and the dispersant is an organic polymer and can be decomposed during sintering to form air holes, so that the quality of the target material is seriously influenced. Chinese patent CN2015101821382 discloses a method for preparing a doped zinc oxide target, but organic polymers such as polyvinyl alcohol, polyacrylic acid, methacrylamide and the like are still used, and the above problems are still not solved. The conventional zinc aluminum oxide film has very high visible light transmittance and good electrical properties, has very low film deposition temperature compared with an indium tin oxide transparent conductive film, has the advantages of rich raw materials, low price, no toxicity, no pollution and the like, can be used as a transparent electrode to replace ITO (indium tin oxide) in many fields of flat panel displays, particularly photovoltaic devices and the like, and thus has attracted wide research interest at home and abroad in recent years. However, researches show that because the atomic radii of Al element and Zn element are greatly different, the doping of Al in ZnO can cause great lattice distortion, and seriously affect the electrical and optical properties of the film, thereby limiting the effective doping range of the ZAO film. In recent years, magnetron sputtering target materials are a new material industry encouraged and developed by the state. On one hand, because the high-end target materials in China are always limited by people, the potential safety hazard of the industry exists, and the technical problems of the preparation of the target materials with high density, high purity, uniform doping, fine and uniform crystal grains, high conductivity and high binding rate are urgently needed to be solved. However, the forming method adopted at present mainly includes organic binder bonding, binder removal or degreasing, such as CN2013103313889, CN2010101276097, and the like, and the above conventional techniques must use organic polymer bonding components such as polyvinyl alcohol, polyethylene glycol, carboxymethyl cellulose, and the like, which are technical difficulties and long-term pain points in the field, and still have the defects of weak applicability and complex process.

Disclosure of Invention

Aiming at the problems, the invention aims to provide a preparation method of a zinc-gallium oxide magnetron sputtering target material.

At present, the main cause of affecting the performance of sputtering targets is micro-non-uniform texture, wherein uniformity mainly includes uniformity on both macro-and micro-texture. A commonly used method in industrial production is magnetron sputtering. Wherein the quality of the magnetron sputtering target material directly affects the performance of the obtained film.

The invention is realized by the following technical scheme:

a preparation method of a zinc-gallium oxide magnetron sputtering target material comprises the following steps:

A. rapidly adding an alkali liquor into a mixed solution of zinc nitrate and gallium nitrate under the rapid stirring condition of 800-1000rpm, stopping adding the alkali liquor when the pH value reaches 8-9, continuously stirring for 15-20min, boiling for 20-30 min by steam, standing for settling, precipitating, placing the precipitate in a centrifuge for dehydration, spreading the dehydrated precipitate in a stainless steel disc, placing the stainless steel disc in a vacuum drier, drying for 4-5 hours at 90-100 ℃, taking out the precipitate, mashing, drying for 8-10 hours, filtering and washing the precipitate, and drying for 12 hours at 100-110 ℃ in a drying box to obtain mixed powder of zinc oxide and gallium oxide;

B. stirring 20 parts of hydroxyl nano gallium oxide and 65 to 70 parts of hydrolysis alcohol into a suspension, heating for 2 to 4 minutes at 60 to 70 ℃, and cooling the suspension to the normal temperature to obtain a hydroxyl nano gallium oxide glue solution;

in the past, people adopt a hydrothermal method to prepare the antibacterial material by hydroxyl gallium oxide.

According to the application, organic binders such as polyvinyl alcohol and the like are not used, the obvious defect of macroscopic pores, namely the weakness of the conventional resistor disc, is avoided, and the process conditions such as the glue discharging speed and the completeness of glue discharging are not required to be considered. From the material preparation perspective, the zinc-gallium oxide sputtering target material has good performance, the high matching purity of the chemical components of the raw material powder is ensured, the local aggregation of impurities and the requirement of the compounding of an initial phase are avoided, the microcosmic components of the raw material powder are ensured to be uniformly distributed, and the particle size range is reasonable.

C. Fully stirring the mixed powder of zinc oxide and gallium oxide in the hydroxyl nano gallium oxide glue solution to uniformly mix the zinc oxide and gallium oxide, drying for 1 to 2h at the temperature of 100 to 110 ℃, then grinding into precursor powder, filling the precursor powder into a mold, pressing into a formed mixed powder prefabricated target at the pressure of 4 to 6MPa, putting the prefabricated target on a gallium oxide sheet, putting the gallium oxide sheet into a high-temperature furnace, and sintering at the high temperature for 8 to 10h to prepare the zinc oxide gallium magnetron sputtering target.

The oxyhydroxide or oxido groups are etherified as a result of the reaction of the hydrated metal oxide with a water-soluble or water-miscible alcohol. This reaction can be carried out with an alcohol alone or in admixture with an organic solvent such as acetone, cyclohexane, toluene or xylene. Although the etherification reaction proceeds slowly at room temperature, it is preferred that the reactants be warmed, or that physical action be applied to the reactants, such as applying shear stress, or that warming and physical action be performed simultaneously to induce etherification, i.e., OEt, based on grafting to hydrated silica or hydrated oxide diamonds. If the etherification reaction is induced by heating, the reaction is preferably carried out at the boiling point of the alcohol at atmospheric pressure. In the case of ethanol reacted with hydrated silica gel, the minimum reaction time is preferably 10 minutes, but the etherification reaction time is much longer when a lower temperature is used.

Further, the alkali solution in the step A is one of a urea solution, a urotropine solution and a sodium carbonate solution, and the mass fraction concentration of the alkali solution in the step A is 5-10%.

Furthermore, the adding amount of the hydroxyl nano gallium oxide emulsion in the step C is 2-3% of the mass of the mixed powder of zinc oxide and gallium oxide, and the temperature of the high-temperature furnace is 450-550 ℃.

Further, in the step A, the concentration of the zinc nitrate and the gallium nitrate in the mixed solution is 1.6 to 2.0 mass percent, and the concentration of the zinc nitrate in the mixed solution is 30 to 31.6 mass percent.

Further, the average grain diameter of the gallium oxyhydroxide is 0.5 to 2 μm.

Gallium oxyhydroxide, also called basic gallium oxide, for example gallium hydroxide, can be heated to 170 ℃ to form basic gallium oxide crystals, which are a hydrolysis product between gallium chloride and gallium hydroxide, and polymerized into an inorganic polymer compound by hydroxyl bridging, also known as a complex or coordination compound. Gallium is the central ion and hydroxide and chlorine are the ligands.

Further, the alcohol hydrolyzed in the step B is one of isopropanol, ethanol and glycol.

The invention has the beneficial effects that:

the working principle of magnetron sputtering is that the interaction of a magnetic field and an electric field is utilized, argon ions bombard the surface of a target material, kinetic energy is conducted in the target material, and then atoms on the surface of the target material are bombarded, fly to a substrate from different angles, and are agglutinated and deposited on the surface of the substrate to form a layer of film. The thin film is very thin, the function of the target is very critical, especially the uniformity of the target, so the target is called as a small and beautiful, small and fine key material. For example, the pores and the uneven distribution can cause the performance of the target material to be greatly reduced. The invention uses hydroxyl gallium oxide, which is called as basic gallium oxide, to polymerize into inorganic polymer compound through hydroxyl bridging, or be a complex or coordination compound, by utilizing transfer etherification reaction, specifically, etherified and hydrolyzable reflected hydroxyl gallium oxide, etherified hydrated inorganic polymer metal oxide, oxide with hydroxyl-hydroxyl gallium oxide, the particles of which are finely dispersed, so as to obtain good etherification effect, control the particle size, conveniently change the hydrated oxide into hydrated metal oxide colloid, further play a role in binding and shaping the precursor powder composed of zinc oxide and zinc oxide, and the hydroxyl gallium oxide can form gallium oxide under high temperature sintering. The purpose of doping gallium is achieved, organic adhesives such as polyvinyl alcohol and the like do not need to be used, glue discharging is not needed, and multiple purposes are achieved at one time. In the past, the quality of prepared sputtering target materials such as zinc oxide and the like is seriously influenced by the conventional mechanical powder mixing process because organic binder is adopted and zinc oxide powder is physically and directly mixed, so that the zinc oxide powder cannot be mixed uniformly and is partially enriched actually, and the organic binder is decomposed to form larger pores and the oxide is not uniformly distributed. The method disclosed by the invention avoids the defects brought by the traditional method.

Compared with the prior art, the invention has the following advantages:

the invention does not use organic binders such as polyvinyl alcohol and the like used by the traditional sputtering target material, does not need complex procedures such as glue discharging and the like, and has the function of bonding and shaping, thereby obtaining the sputtering zinc oxide ceramic target material containing gallium oxide, the prepared gallium oxide film has a wurtzite structure, has a (002) surface structure, improves the matrix temperature, improves the film crystallinity, increases the crystal grains, reduces the lattice distortion, is not easy to generate larger lattice distortion under the condition that more gallium is doped, and simultaneously has stable gallium element and difficult to oxidize, so the thermal stability of the zinc gallium oxide film is higher, and the zinc gallium oxide film also has good infrared reflection performance, thereby not only being used as a transparent electrode in a solar cell and a flat panel display, but also being used as a heat insulation film and the like.

Detailed Description

The invention is illustrated by the following specific examples, which are not intended to be limiting.

Example 1

Firstly, quickly adding alkali liquor into a mixed solution of zinc nitrate and gallium nitrate under the condition of quick stirring at 1000rpm, stopping adding the alkali liquor when the pH value reaches 9, continuously stirring for 20min, boiling for 30 min by steam, standing for settling, separating out precipitate, placing the precipitate in a centrifugal machine for dehydration, flatly paving the dehydrated precipitate in a stainless steel disc, placing the stainless steel disc in a vacuum drier, drying for 5 hours at 100 ℃, taking out the precipitate for mashing, drying for 10 hours again, filtering and washing the precipitate, and keeping the temperature in a drying oven at 110 ℃ for drying for 12 hours to obtain mixed powder of zinc oxide and gallium oxide;

secondly, stirring 20 parts by weight of hydroxyl nano gallium oxide and 70 parts by weight of hydrolytic alcohol to form a suspension, heating at 70 ℃ for 4min, and cooling the suspension to normal temperature to obtain a hydroxyl nano gallium oxide glue solution;

and then, sufficiently stirring the hydroxyl nano gallium oxide glue solution and the mixed powder of zinc oxide and gallium oxide to uniformly mix the hydroxyl nano gallium oxide glue solution and the mixed powder of zinc oxide and gallium oxide, drying for 2 hours at 110 ℃, then grinding into precursor powder, putting the precursor powder into a mold, pressing into a formed mixed powder prefabricated target at 6MPa, putting the prefabricated target on a gallium oxide sheet and putting the gallium oxide sheet into a high-temperature furnace, and sintering for 10 hours at high temperature to prepare the zinc oxide gallium magnetron sputtering target material, wherein the alkali solution in the step A is a urea solution with the mass fraction concentration of 5%, the hydroxyl nano gallium oxide emulsion in the step C is 3% of the mass of the mixed powder of zinc oxide and gallium oxide, the temperature in the high-temperature furnace is 550 ℃, and the zinc nitrate and gallium nitrate mixed solution in the step A is a mixed solution with the mass fraction concentration of 2.0% and the mass fraction concentration of 31.6% of zinc nitrate, the average particle size of the hydroxyl nano gallium oxide of B is 2 microns, and the hydrolytic alcohol in the step B is ethylene glycol.

Preparing 5mmol/L CTAB deionized water solution from gallium oxyhydroxide, taking out 1.5ml of gallium benzene chloride saturated solution by a liquid transfer device, putting the solution into a beaker, diluting the solution to 15ml by benzene, putting the diluted solution into an ultrasonic instrument for ultrasonic treatment, dropwise adding the prepared CTAB deionized water solution into the beaker by an injector in the ultrasonic treatment process, wherein the color of the solution is changed in the process, the color of the initial solution is brown, the color of the solution is changed from brown to purple after the CTAB deionized water solution is dropwise added, stopping adding the CTAB deionized water solution when the solution is colorless finally, taking out the beaker, closing the ultrasonic instrument, putting the mixed liquid in the beaker into a polytetrafluoroethylene reaction kettle with the capacity of 200ml, sealing, putting the kettle into an oven, heating to 180 ℃, and keeping the temperature for 12 hours. Obtaining white precipitate, centrifugally cleaning the precipitate with deionized water or ethanol for three times, and drying the precipitate to finally obtain the gallium oxyhydroxide nano material. Plays a role in binding, and simultaneously forms the zinc-gallium oxide magnetron sputtering target material by high-temperature calcination.

Wherein the density of the product planar target material is 5.56g/cm ³ The target material has no impurities, the target material has the bulk defect of holes with the pore diameter larger than 2mm, the flatness of the target material is 0.4mm, the average diameter of crystal grains is 17 mu m, the maximum diameter of the crystal grains is 47 mu m, the distribution of the crystal grain diameters is approximately uniform, and the oxygen loss rate of the target material is 3.4 percent.

Comparative example 1

Compared with the embodiment 1, the precursor powder in the third step is replaced by putting the mixture of zinc oxide and gallium oxide into a mechanical powder mixing method, mixing the powder in a ball milling tank for 48 hours, and the other steps are the same, so that the corresponding zinc-gallium oxide target is manufactured, except the steps of the other methods are the same.

Wherein the density of the product target material is 5.17g/cm ³ The target material contains impurities with black spots, has the defects of a hole with the diameter larger than 2mm, has the flatness of 0.5mm, the average diameter of crystal grains is 8 mu m, the maximum diameter of the crystal grains is 45 mu m, the distribution of the crystal grain diameters is not uniform, and the oxygen loss rate of the target material is 4.8 percent.

Example 2

Firstly, under the condition of fast stirring at 800rpm, quickly adding alkali liquor into a mixed solution of zinc nitrate and gallium nitrate, stopping adding the alkali liquor when the pH value reaches 8, continuing stirring for 15min, boiling with steam for 20min, then standing for settling, separating out precipitate, placing the precipitate in a centrifugal machine for dehydration, spreading the dehydrated precipitate in a stainless steel disc, placing the stainless steel disc in a vacuum drier, drying for 4 hours at 90 ℃, taking out the precipitate for mashing, drying for 8 hours again, filtering and washing the precipitate, and keeping the temperature in a drying oven at 100 ℃ for drying for 12 hours to obtain mixed powder of zinc oxide and gallium oxide;

secondly, stirring 15 parts of hydroxyl nano gallium oxide and 65 parts of hydrolytic alcohol into a suspension, heating for 2min at 60 ℃, and cooling the suspension to normal temperature to obtain hydroxyl nano gallium oxide glue solution;

and then, sufficiently stirring the mixed powder of zinc oxide and gallium oxide in hydroxyl nano gallium oxide glue solution to uniformly mix the zinc oxide and gallium oxide, drying for 1h at 100 ℃, then grinding into precursor powder, putting the precursor powder into a mold, pressing at 4MPa to form a formed mixed powder prefabricated target, putting the prefabricated target on a gallium oxide sheet and putting the gallium oxide sheet into a high-temperature furnace, and sintering at high temperature for 8h to prepare the zinc-gallium oxide magnetron sputtering target material, wherein the alkali solution in the step A is a sodium carbonate solution with the mass fraction concentration of 10%, the hydroxyl nano gallium oxide emulsion in the step C is added in an amount which is 2% of the mass of the mixed powder of zinc oxide and gallium oxide, the temperature of the high-temperature furnace is 450 ℃, and the zinc nitrate and gallium nitrate mixed solution in the step A is a zinc nitrate and gallium nitrate mixed solution with the mass fraction concentration of 1.6%, the mass fraction concentration of zinc nitrate is 31.6%, the average particle size of the gallium oxide hydroxide in the step B is 0.5 mu m, and the alcohol in the step B is isopropanol.

Zinc nitrate solution: adding 75kg of distilled water into an acid-resistant cylinder, adding 23kg of zinc granules, slowly adding 58% by mass of nitric acid, wherein the acid adding speed is forbidden to be too high so as to avoid a large amount of nitric oxide and nitric acid overflowing from a bottle, and the total amount of the added acid is 60kg, and when no bubbles occur any more, the acid-resistant glass bottle is obtained.

Wherein the density of the product rotary target material is 5.57g/cm ³ The target material has no impurities, the target material has no body defects of holes with the pore diameter larger than 2mm, the flatness of the target material is 0.5mm, the average diameter of crystal grains is 18 mu m, the maximum diameter of the crystal grains is 45 mu m, the distribution of the crystal grain diameters is approximately uniform, the oxygen loss rate of the target material is 3.4 percent, and the color difference delta E =1.3.

Comparative example 2

Compared with the embodiment 2, in the third step, the hydroxyl nanometer gallium oxide glue solution is replaced by the same amount of polyvinyl alcohol in the comparison embodiment 2, except that the other steps are the same.

Wherein the density of the product target material is 5.25g/cm ³ The target material comprises impurities of black spots, body defects of holes with the pore diameter larger than 2mm, the target material flatness is 0.6mm, the average diameter of crystal grains is 20 mu m, the maximum diameter of the crystal grains is 61 mu m, the distribution of the crystal grain diameters is not uniform, the oxygen loss rate of the target material is 3.9%, and the color difference delta E =3.2.

Note: detecting the density of the target material zinc gallium oxide magnetron sputtering target material according to the specification of GB/T25995-2010 fine ceramic density and apparent porosity test method; the surface quality of the product is detected according to the regulation of the GB/T20967-2007 general rule of nondestructive detection and visual detection; measuring the color difference of the target according to the specification of a GB/T11942-1989 color building material chromaticity measuring method; the internal defects of the target are tested according to a method specified by a GB/T8651-2015 metal plate ultrasonic flaw detection method, and the internal defects of the rotary target are tested according to a method specified by a CB/T12969.1-2007 titanium and titanium alloy pipe ultrasonic flaw detection method; the oxygen loss rate of the target material is determined according to the specification of the T/ZZB0639-2018 zinc-gallium oxide magnetron sputtering target material; the average grain diameter sample is prepared according to a GB/T13298-2005 metal microstructure inspection method, and the average grain diameter inspection is carried out by adopting the specification of a GB/T6394-2017 metal average grain size determination method.

Claims

1. The preparation method of the zinc-gallium oxide magnetron sputtering target material is characterized by comprising the following steps of:

B. stirring 15 to 20 parts by weight of hydroxyl nano gallium oxide and 65 to 70 parts by weight of hydrolysis alcohol to form a suspension, heating for 2 to 4 minutes at 60 to 70 ℃, and cooling the suspension to the normal temperature to obtain a hydroxyl nano gallium oxide glue solution;

C. adding hydroxyl nano gallium oxide glue solution into zinc oxide and gallium oxide mixed powder, fully stirring to mix uniformly, drying for 1-2h at 100-110 ℃, then grinding into precursor powder, filling the precursor powder into a mold, pressing at 4-6 MPa to form a mixed powder prefabricated target, putting the prefabricated target on a gallium oxide sheet, putting the gallium oxide sheet into a high-temperature furnace, and sintering at high temperature for 8-10h to prepare the zinc-gallium oxide magnetron sputtering target.

2. The method for preparing a zinc-gallium oxide magnetron sputtering target according to claim 1, wherein the alkali solution in step A is one of a urea solution, a urotropine solution and a sodium carbonate solution, and the mass fraction concentration of the alkali solution in step A is 5-10%.

3. The preparation method and the application of the zinc-gallium oxide magnetron sputtering target material according to claim 1, wherein the adding amount of the hydroxyl nano-gallium oxide emulsion in the step C is 2-3% of the mass of the mixed powder of zinc oxide and gallium oxide, and the high temperature furnace temperature is 450-550 ℃.

4. The method for preparing the zinc gallium oxide magnetron sputtering target material according to claim 1, wherein the zinc nitrate and gallium nitrate mixed solution obtained in the step A has a gallium nitrate mass fraction concentration of 1.6 to 2.0% and a zinc nitrate mass fraction concentration of 30 to 31.6%.

5. The method for preparing a zinc gallium oxide magnetron sputtering target material according to claim 1, wherein the average particle size of gallium oxyhydroxide is 0.5 to 2 μm.

6. The method for preparing a zinc-gallium oxide magnetron sputtering target according to claim 1, wherein the alcohol hydrolyzed in the step B is one of isopropanol, ethanol and ethylene glycol.