JPH07150362A - Production of ysz buffer layer on sapphire - Google Patents

Abstract

PURPOSE:To produce a YSZ thin film having good orientability by acting ultrasonic waves on a raw material soln. in a vessel to generate an aerosol and spraying this aerosol onto a sapphire which is previously heated. CONSTITUTION:The raw material soln. 9 consisting of a metal salt is put into the vessel 7. The aerosol 8 of the raw material soln. 9 is generated when the ultrasonic waves is generated by actuating an ultrasonic vibrator transducer 17. The generated aerosol 8 is passed in an aerosol spraying pipe 4 and is put into a reaction tube 10 under the atm. pressure. The aerosol 8 made into a mist form is sprayed as a precursor perpendicularly atop the sapphire 16. The sapphire 16 is previously heated to about 770 deg.C. The aerosol 8 is thermally cracked at the moment the aerosol collides against the sapphire 16, by which the film formation is executed. As a result, the good-quality YSZ thin film is formed on the sapphire 16. Then, a YSZ buffer layer having the excellent controllability of the film thickness is produced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to YSZ on sapphire.
The present invention relates to a method for manufacturing a buffer layer.

[0002]

2. Description of the Related Art YSZ (yttria-stabilized-zilconia), C, which is highly oriented as a buffer layer in order to alleviate lattice constant mismatch when an oxide superconductor is formed on sapphire, C
A thin film of an oxide such as eO _{2 having} a fluorite type crystal structure is used. Conventionally, electron beam evaporation,
Ion beam sputtering, pulse laser ablation, CVD, solution method, etc. are used. In addition,
The YSZ thin film is also used as an electrolyte layer material of a solid oxide fuel cell.

[0003]

Electron beam evaporation, ion beam sputtering, pulsed laser ablation, CVD, etc. all require a vacuum device and are therefore high-cost manufacturing methods. Also, the solution method has high controllability of film thickness. It has inferior drawbacks.

The present invention has been made in view of the above points, and it is possible to form a YSZ thin film having good orientation on sapphire at low cost, and to provide a YSZ buffer layer having excellent controllability of the film thickness. It is intended to provide a manufacturing method.

[0005]

In order to solve the above problems, the present invention is a method for producing a highly oriented YSZ thin film on sapphire, which comprises the step of putting a raw material solution into a container of an aerosol generator under atmospheric pressure. And a step of generating an aerosol by applying ultrasonic waves to the raw material solution in the container, a step of spraying the aerosol, and a YSZ film obtained by spraying the sprayed aerosol as a precursor on sapphire preheated with an infrared lamp or the like. And a step of forming a film.

[0006]

The film forming operation is all performed under atmospheric pressure, and the temperature of only the substrate rises to a high temperature, but the other parts operate at room temperature, so the operation is simple and easy.

[0007]

EXAMPLES The present invention will be described below with reference to examples.

FIG. 1 is a perspective view showing a schematic structure of an apparatus for carrying out the method for producing a YSZ buffer layer on sapphire according to the present invention.

The aerosol generator 1 is a sealed container containing water, an ultrasonic vibrator 17 is attached to the bottom inside the aerosol generator 1, and a raw material solution containing Y and Zr is placed on the water. A bowl-shaped container 7 containing 9 is floating. A carrier gas feed pipe 2 is connected to one end of the aerosol generator 1, and an aerosol feed pipe 3 is attached to the other end.

The T-shaped reaction tube 10 is composed of one upright branch tube 11 and two horizontal branch tubes 12, made of transparent quartz glass, and its three openings are closed by plugs 13 made of silicone rubber. ing. One end of the aerosol delivery pipe 3 penetrates a plug 13 fitted in the opening of the upright branch pipe 11, and an aerosol spray pipe 4 is slidably fitted to the end of the aerosol delivery pipe 3. The aerosol feed pipe 3 is made of a rubber hose, a glass pipe, a polymer tube, or the like, and the aerosol spray pipe 4 is made of quartz glass.

Inside the reaction tube 10, a susceptor 15 is horizontally arranged below the aerosol spray tube 4 in the vertical direction, and a sapphire 16 as a substrate is placed on the upper surface of the susceptor 15. The susceptor 15 is made of a metal such as Ni.

The sapphire 16 is positioned immediately below the spray port 5 of the aerosol spray tube 4. The interval H between the sapphire 16 and the spray port 5 of the aerosol spray tube 4 can be adjusted by sliding the aerosol spray tube 4 up and down, and the interval H can be shortened to 1 to 2 cm.

Two horizontal branch tubes 1 on the left and right of the T-shaped reaction tube 10.
The exhaust pipes 14 penetrate through the plugs 13 fitted in the openings of the two.

An infrared lamp 6 is arranged as a heater of the susceptor 15 just below the susceptor 15 outside the T-shaped reaction tube 10.

The steps of forming the YSZ (yttria-stabilized zirconia) film of the present invention will be described in order. (1) A metal salt such as octylate or naphthenate is placed as a raw material solution 9 in a container 7 inside the aerosol generator 1 under atmospheric pressure. (2) When the ultrasonic oscillator 17 is operated to generate ultrasonic waves, the aerosol 8 of the raw material solution 9 is generated. (3) Air as a carrier gas is supplied into the aerosol generator 1 through the carrier gas inlet pipe 2. (4) Aerosol 8 generated in the aerosol generator 1
Ride on the carrier gas, pass through the aerosol feed pipe 3 and the aerosol spray pipe 4, and enter the reaction pipe 10 under atmospheric pressure. (5) From the aerosol spray tube 4 to the sapphire 1 using the aerosol 8 of metal salt atomized by ultrasonic waves as a precursor.
Spray vertically on top of 6. Infrared lamp 6 beforehand
The susceptor 15 is already heated by activating the sapphire, and the temperature of the sapphire 16 thereon is raised to about 770 ° C. Therefore, the aerosol 8 is sapphire 16
The film is formed by thermal decomposition at the moment it collides with. (6) Exhaust gas generated in the reaction tube 10 is exhaust pipe 14
Is discharged to the outside through. (7) In this way, good quality YS on sapphire 16
A Z thin film is formed.

In the above work, only the susceptor 15 is heated by the infrared lamp 6 and the reaction tube 10 is not heated. By providing a distance H between the surface of the sapphire 16 and the spray port 5 of the aerosol spray tube 4, the aerosol 8
It can be adjusted to impinge on only the sapphire 16 and thermally decompose. All of the above operations are performed under atmospheric pressure, there is no need to work in a vacuum, and as described above, the temperature of sapphire 16 rises to about 770 ° C,
Other parts can be worked at room temperature.

In the above embodiment, the reaction tube 10 is T-shaped, but other shapes may be used. For example, instead of the two horizontal branch tubes 12, four horizontal branch tubes or eight horizontal branch tubes are used. May be used. In short, it is important to vertically arrange the aerosol spray pipe 4 in the upright branch pipe 11 and horizontally arrange the sapphire 16 directly below it.

Next, an example of an experiment when the method of the present invention is carried out on sapphire will be shown.

The experimental specifications are shown in the following table.

[0020]

[Table 1] FIG. 2 is a graph showing the results of X-ray diffraction of the thin film produced in the above experiment.

FIG. 2 shows the orientation of the thin film at a substrate temperature of 750 ° C. From this graph, it can be seen that the (111) plane is preferentially oriented.

[0022]

As described above, in the method of manufacturing the YSZ buffer layer on the sapphire of the present invention, only the sapphire can be heated to a high temperature by heating the susceptor inside the transparent quartz tube using infrared rays. Since the atomizing port of the aerosol is brought close to the sapphire to a distance of 1 to 2 cm, and the solution is atomized by using ultrasonic waves, the following excellent effects can be obtained. (1) All film forming operations are performed under atmospheric pressure,
Only sapphire rises in temperature to 770 ° C, but the other parts are configured to operate at room temperature, so the device is simple, inexpensive, and easy to work with. (2) With this device, a dense and uniform YSZ thin film with high orientation can be formed. (3) In particular, when metal soap is used as the metal salt as a raw material, a thin film having good orientation can be obtained.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional perspective view showing a schematic configuration of an apparatus for carrying out a method for producing a YSZ buffer layer on sapphire according to the present invention.

FIG. 2 is a graph showing the orientation of a thin film produced using the method of the present invention.

[Explanation of symbols]

 1 T-shaped reaction tube 2 Carrier gas inlet tube 3 Aerosol supply tube 4 Aerosol spray tube 5 Spray port 6 Infrared lamp 7 Bowl-shaped container 8 Aerosol 9 Raw material solution 10 T-shaped reaction tube 11 Upright branch tube 12 Horizontal branch tube 13 Plug 14 Exhaust pipe 15 Susceptor 16 Sapphire 17 Ultrasonic transducer

Claims (1)

[Claims] 1. A method for producing a highly oriented YSZ thin film on sapphire, comprising the steps of placing a raw material solution in a container in an aerosol generator under atmospheric pressure, and applying ultrasonic waves to the container raw material solution. A method for producing a YSZ buffer layer on sapphire, which comprises the steps of: generating an aerosol by applying the aerosol and spraying the aerosol onto a pre-heated sapphire to form a YSZ film.