JPS584922Y2 - Zinc oxide thin film production equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention is based on the structure of an apparatus for producing a zinc oxide thin film, and particularly relates to an apparatus for making oxygen reacted with zinc luminescent.

・ □゛・. Zinc oxide thin films are attracting attention as piezoelectric materials used in surface acoustic wave devices and the like.

A sputtering method has conventionally been used as a method for manufacturing this zinc oxide thin film.

However, the sputtering method has the disadvantage that the rate of vapor deposition of zinc oxide □ is slow and that high-energy particles fly out from the target and deteriorate the vapor deposited film.

Therefore, it has been considered to obtain a zinc oxide thin film by an ion-blating method instead of a sputtering method.

FIG. 1 &J shows a schematic diagram of an apparatus used for the high frequency ion blating method, which is an example of the method.

An evaporation source 11 and a substrate holder 12 are provided in the bell jar 10, and a DC electric field is applied between them.

Zinc is placed in the evaporation source and heated to vaporize it.

The vaporized zinc is ionized as it passes through the plasma discharge region formed by the radio frequency electrode 13.

At the same time, oxygen □ introduced into the bell jar 10 is also ionized in the plasma discharge region.

The ionized particles are accelerated by a DC electric field applied between the evaporation source 11 and the substrate holder 12 and are deposited on the substrate 14 to form a zinc oxide thin film.

The plasma discharge region ionizes zinc and oxygen to promote and accelerate the reaction.

The above-mentioned ion brazing method has the following drawbacks.Firstly, since the reaction between zinc and oxygen is carried out in a brazing machine, the resulting zinc oxide particles become easier to process into a band wax. .

□When these charged particles adhere to the substrate, the substrate becomes charged,
It repels particles that adhere later and becomes an obstacle to the formation of a zinc oxide thin film.

Another drawback is that the ions of the inert gas introduced into the belljar to generate discharge impact the substrate, roughening the film surface and raising the temperature of the substrate.

The purpose of this invention is to improve the above-mentioned drawbacks,
The object of the present invention is to obtain an apparatus for producing a ml hot pot that promotes the reaction between zinc vapor and oxygen and eliminates the influence of ions on the film surface and substrate.

The zinc oxide thin film manufacturing apparatus according to the present invention is an apparatus equipped with a means for supplying only activated acid to the reaction area with zinc and preventing ionized particles from flowing into the reaction area. be.

The drawings will be explained below.

FIG. 2 is a diagram schematically showing an apparatus for producing a zinc oxide thin film according to the present invention.

An evaporation source 21 and a substrate holder '22 are placed facing each other in the Belsha 20.

It is preferable that the evaporation source 21 be a closed crucible to eject high-pressure steam into a bell jar.

This causes the zinc vapor to move toward the substrate with constant kinetic energy.

Oxygen is supplied to the region where zinc vapor advances, and zinc and oxygen react to form zinc oxide. In order to promote the reaction between zinc and oxygen, oxygen may be ionized.

Preferably, the reaction region between zinc and oxygen is outside the plasma discharge region.

For this purpose, in the zinc oxide thin film manufacturing apparatus according to the present invention, two electrodes are provided as shown in FIG.

That is, the first electrode 25 is provided surrounding the region connecting the evaporation source and the substrate holder.

Furthermore, a second electrode 26 is provided surrounding this first electrode.

An electric field is applied between the first electrode 25 and the second electrode 26 to generate a discharge.

The electric field may be direct current or alternating current.

The discharge generated between these two electrodes ionizes or activates oxygen molecules present in the discharge region.

The ionized particles are attracted to the electrode, but the activated oxygen flows out of the discharge region.

This activated oxygen is reacted with zinc to obtain zinc oxide.

The ionized particles are attracted to the electrode and become neutralized, and are further ionized or activated.

Zinc vapor directed towards the substrate does not pass through the plasma discharge area;
It is not ionized and the crushed zinc oxide is not charged.

1.1 Figure 3 shows the above-mentioned first electrode and second electrode.
FIG. 3 is a perspective view of an example of an electrode.

The first electrode 35 has a cylindrical mesh,
The second electrode is similarly formed into a cylindrical shape with a large circumference.

These electrodes may be metal plates with holes, -
! It may also be a prismatic shape.

That is, a cylindrical discharge region is formed by the first electrode and the second electrode, and the activated oxygen is allowed to escape between the first electrodes.

According to the present invention, only activated oxygen reacts with zinc to form zinc oxide, so particles adhering to the substrate are not charged and do not interfere with film formation.

Therefore, the efficiency of vapor deposition also increases. Further, since it is possible to prevent ionized particles from colliding with the substrate and roughening the film surface, a film with an excellent crystal structure can be obtained.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a conventional zinc oxide thin film manufacturing equipment, Figure 2
The figure is a schematic diagram of the device according to the present invention, and FIG. 3 is a perspective view of the electrode used in the device according to the present invention. 10.20...Berja, 11,21...
...Evaporation source, 12, 22...Substrate 4 holder, 2
5, 35...first electrode, 26t3. j,'・
...Second electrode.

Claims (1)

[Scope of utility model registration request] □ Zinc is heated in an oxygen-containing atmosphere to vaporize it, and the zinc vapor and oxygen are reacted to form zinc heptoxide. □ Zinc oxide thin film is deposited on the substrate. a first electrode surrounding at least a portion of the connecting region and a second electrode surrounding the first electrode, and means for applying an electric field between the first electrode and the second electrode; An apparatus for manufacturing a zinc oxide thin film, characterized in that a discharge is generated between the first electrode and the second electrode.