CN115747744A

CN115747744A - Indium gallium oxide film and preparation method thereof

Info

Publication number: CN115747744A
Application number: CN202310015543.XA
Authority: CN
Inventors: 陈雪庆; 崔云涛; 田利丰; 刘静
Original assignee: Technical Institute of Physics and Chemistry of CAS
Current assignee: Technical Institute of Physics and Chemistry of CAS
Priority date: 2023-01-06
Filing date: 2023-01-06
Publication date: 2023-03-07
Anticipated expiration: 2043-01-06
Also published as: CN115747744B

Abstract

The invention belongs to the technical field of semiconductor material preparation, and particularly relates to a gallium indium oxide film and a preparation method thereof. The method comprises the following steps: 1) Forming a gallium-indium alloy layer on the surface of the solid metal target; 2) Sputtering the gallium-indium alloy layer on the surface of the solid metal target material in the step 1) by using a magnetron sputtering method, and depositing a film on the substrate; 3) And (3) annealing the film obtained in the step 2) in an oxygen-containing atmosphere to obtain the gallium indium oxide film. The preparation method successfully prepares the gallium indium oxide film with excellent performance by the magnetron sputtering method, fills the blank in the field, and has low cost and simple process flow.

Description

Gallium indium oxide film and preparation method thereof

Technical Field

The invention belongs to the technical field of semiconductor material preparation, and particularly relates to a gallium indium oxide film and a preparation method thereof.

Background

Since the 50 s of the 20 th century, semiconductor materials have been widely used in today's electronic information technology, particularly in device applications such as computer microprocessors, solar cells, power amplifiers, and the like. The traditional semiconductor material is difficult to be used for high-frequency, high-mobility and high-power devices due to the characteristics of low breakdown field strength and small forbidden band width.

The liquid metal is a simple metal and an alloy which are in a liquid state at a temperature of below 660 ℃, and the more commonly used liquid metal is a metal which is in a liquid state at a temperature close to room temperature, such as gallium or an alloy thereof with a melting point below 30 ℃, or a low-melting-point metal alloy which can be in a liquid state at a slightly higher temperature range, such as 40-200 ℃, such as bismuth, indium, tin, zinc and the like. In recent years, with the progress of a series of important researches, the application value of liquid metal is more and more important.

Oxides of the various components of the liquid metal can be used as semiconductor materials, for example: gallium oxide (Ga) ₂ O ₃ ) Indium oxide (In) ₂ O ₃ ) Tin oxide (SnO) ₂ ) And the like, and has wide application prospect in the field of high-power devices. At present, the preparation method of the liquid metal oxide mainly comprises a chemical deposition method, a sol-gel method, a magnetron sputtering method and the like.

The sol-gel method is easy to introduce impurities and pollute the environment, the liquid metal oxide film prepared by the chemical vapor deposition method has poor adhesive force with a matrix and is easy to fall off, and the magnetron sputtering method can overcome the defects of the prior method.

Magnetron sputtering is one type of Physical Vapor Deposition (PVD). The magnetron sputtering technology can be used for preparing multi-materials such as metal, semiconductor, insulator and the like, and has the advantages of simple equipment, easy control, large coating area, strong adhesive force and the like. In the magnetron sputtering, in an orthogonal electromagnetic field, a closed magnetic field restrains electrons to make spiral motion around a target surface, argon continuously collides with working gas in the motion process to ionize a large amount of argon ions, the argon ions bombard a target material at an accelerated speed under the action of the electric field, and sputtered target atomic ions (or molecules) are deposited on a substrate to form a film. The liquid metal target is needed for preparing the liquid metal oxide film by the magnetron sputtering method, but part of liquid metal such as gallium indium alloy has low melting point or is liquid at normal temperature and cannot be directly used as the target for sputtering, so the process for preparing the gallium indium oxide film by the magnetron sputtering method needs to be researched.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide the gallium indium oxide film and the preparation method thereof.

Specifically, the invention firstly provides a preparation method of a gallium indium oxide film, which comprises the following steps:

1) Forming a gallium-indium alloy layer on the surface of the solid metal target;

2) Sputtering the gallium-indium alloy layer on the surface of the solid metal target material in the step 1) by using a magnetron sputtering method, and depositing a film on the substrate;

3) And 3) annealing the film obtained in the step 2) in an oxygen-containing atmosphere to obtain the gallium indium oxide film.

The invention finds that the gallium indium oxide film with excellent performance can be prepared by combining the gallium indium alloy with common solid metal target materials such as copper, iron and zinc target materials to obtain the solid metal target material with the surface adhered with the gallium indium alloy for magnetron sputtering, controlling the whole process of the magnetron sputtering, such as carrier gas, target base distance, sputtering power and the like, and combining an annealing process at a specific temperature.

Preferably, in step 1), the surface of the solid metal target is infiltrated by the liquid gallium-indium alloy under an acidic condition to form the gallium-indium alloy layer.

Preferably, in the step 1), the gallium-indium alloy has a gallium mass fraction of 20% to 80%.

Preferably, in step 2), the carrier gas of the magnetron sputtering method is a mixed gas of argon and oxygen, wherein the flow rate of argon is 20-40sccm, and the flow rate of oxygen is 0.2-4sccm. Under the flow of argon and oxygen, the film forming quality of gallium indium oxide is optimal, wherein too high argon flow causes too many collision times before sputtering atoms reach the substrate, so that much energy is lost, the migration capability is limited after the sputtering atoms reach the substrate, the crystallization quality is poor, and too low argon flow causes difficulty in gas ionization and sputtering glow starting effect.

Preferably, in the step 2), the target base distance of the magnetron sputtering method is 15-30mm. The invention discovers that the effect of the target base distance is optimal for gallium-indium alloy, the target base distance is higher than 30mm, the number of collisions of sputtered atoms reaching the substrate is excessive, the energy loss is large, the nucleation and growth of the film are not facilitated, and the deposition rate is reduced, however, if the target base distance is lower than 15mm, the film is bombarded by charged particles, and the deposition rate is too high, so that the density of various defects in the film is increased.

Preferably, in the step 2), the sputtering power of the magnetron sputtering method is 50-100W. When the sputtering power is lower than 50W, the deposition rate is low, and the energy of sputtering atoms reaching the substrate is also low; when the sputtering power is higher than 100W, the sputtering particle energy can be increased, but the deposition rate is too high, which affects the quality of the indium gallium oxide film.

Preferably, in the step 2), the sputtering time of the magnetron sputtering method is 5-60min, and more preferably 15-30min.

Preferably, in step 2), the temperature of the substrate is 25 to 400 ℃.

Preferably, in step 3), the oxygen-containing atmosphere is oxygen. The present inventors have found that the use of the oxygen-containing atmosphere described above facilitates further oxidation of the film to form a stable crystal structure.

Preferably, in the step 3), the temperature of the annealing treatment is 200-1000 ℃, and more preferably 650-750 ℃; the time of the annealing treatment is 3-6h, and 4h is preferred. Experiments show that the crystallinity of the obtained gallium indium oxide film can be obviously improved by annealing at 650-750 ℃ for 3-6h.

The invention also provides a gallium indium oxide film which is prepared by the preparation method.

The invention has the beneficial effects that:

according to the invention, the gallium-indium alloy is combined with common solid metal targets such as copper, iron and zinc targets to obtain the solid metal target with the surface attached with the gallium-indium alloy, and then the gallium-indium oxide thin film prepared by combining a specific magnetron sputtering method with an annealing process is high in crystallinity and light transmittance and excellent in performance, and the gallium-indium oxide thin film is low in cost and simple in process flow.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the prior art in the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is an SEM photograph of a gallium indium oxide thin film prepared by the method of example 1.

FIG. 2 is an SEM image of the gallium indium oxide thin film prepared by the method of example 1 after annealing.

FIG. 3 is the XRD pattern after annealing for preparing the indium gallium oxide thin film in example 1 of the present invention.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention. Modifications or substitutions to methods, steps or conditions of the present invention may be made without departing from the spirit and scope of the invention.

The examples do not show the specific techniques or conditions, according to the technical or conditions described in the literature in the field, or according to the product specifications. All reagents or instruments are conventional products which are not indicated by manufacturers and are available from regular distributors.

Example 1

A preparation method of a gallium indium oxide film comprises the following steps:

1. immersing the copper substrate into hydrochloric acid to contact with the liquid metal gallium-indium alloy, so as to infiltrate the liquid metal gallium-indium alloy on the copper substrate to prepare a liquid metal target material;

2. sputtering the gallium-indium alloy layer on the surface of the copper substrate in the step 1 by using a magnetron sputtering method, and depositing a film on the substrate under the conditions of argon flow of 30sccm, oxygen flow of 0.3sccm, target base distance of 30mm, substrate temperature of 25 ℃, sputtering power of 50W and sputtering time of 30min to obtain a film SEM image as shown in FIG. 1;

3. after the film is prepared, the film is annealed for 4 hours in an oxygen environment at 700 ℃ in a muffle furnace, and an SEM image of the processed film is shown in FIG. 2. XRD analysis is carried out on the annealed film, and an XRD spectrum is obtained and shown in figure 3.

As can be seen from the SEM images before and after annealing in fig. 1-2, the thin film state before annealing was flaky and had no apparent particle structure; the annealed film structure is gradually changed into a stacked structure, and obvious particles can be seen, which indicates that the crystallinity of the film is remarkably increased by annealing. As can be seen from the XRD image of fig. 3, intensity peaks of Ga2O3, gaInO3 and (Ga, in) O3 appear In the image, indicating that the component In the thin film is a liquid metal oxide (one of the three or a mixture of the three); siO2 appears because the substrate for preparing the film is a silicon wafer.

The above examples are only for describing the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, and various modifications and improvements made to the technical solution of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A preparation method of a gallium indium oxide film is characterized by comprising the following steps:

1) Forming a gallium-indium alloy layer on the surface of the solid metal target material;

2. The method for preparing an indium gallium oxide thin film according to claim 1, wherein in step 1), the surface of the solid metal target is infiltrated by a liquid indium gallium alloy under an acidic condition to form the indium gallium alloy layer.

3. The method for preparing the gallium indium oxide film according to claim 1 or 2, wherein in the step 1), the gallium indium alloy contains 20% -80% of gallium by mass.

4. The method for preparing the gallium indium oxide thin film according to claim 1 or 2, wherein in the step 2), the carrier gas of the magnetron sputtering method is a mixed gas of argon and oxygen, wherein the flow rate of the argon is 20-40sccm, and the flow rate of the oxygen is 0.2-4sccm.

5. The method for preparing the indium gallium oxide thin film according to claim 1 or 2, wherein in step 2), the target base distance of the magnetron sputtering method is 15-30mm.

6. The method for preparing the indium gallium oxide thin film according to claim 1 or 2, wherein in the step 2), the sputtering power of the magnetron sputtering method is 50-100W;

the sputtering time of the magnetron sputtering method is 5-60min.

7. The method for preparing an indium gallium oxide thin film according to claim 1 or 2, wherein in step 2), the temperature of the substrate is 25 to 400 ℃.

8. The method for preparing an indium gallium oxide thin film according to claim 1 or 2, wherein in step 3), the oxygen-containing atmosphere is oxygen.

9. The method for preparing the indium gallium oxide thin film according to claim 1 or 2, wherein in the step 3), the temperature of the annealing treatment is 200-1000 ℃;

the time of the annealing treatment is 3-6h.

10. An indium gallium oxide thin film produced by the method for producing an indium gallium oxide thin film according to any one of claims 1 to 9.