JPS592107Y2 - Zinc oxide film production equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for manufacturing zinc oxide films, and in particular to the structure of an apparatus for mass production.

Zinc oxide films are attracting attention as materials for surface wave devices and other devices.

Methods for manufacturing this zinc oxide film include sputtering method, ion blasting method, 1. There are C, B, D methods, etc., and the sputtering method is generally used from the viewpoint of crystal axis orientation and specific resistance.

However, when producing a zinc oxide film by sputtering, the deposition rate is as slow as 1 μm/hr, and there are problems in that cloudiness or damage occurs when the film thickness reaches about 20 μm.

Therefore, a reactive beam evaporation method has been considered as a method for producing a zinc oxide film with stable film quality at high speed.

In this method, zinc is heated and vaporized, reacted with activated oxygen in a high-frequency discharge region to form zinc oxide, and this is vapor-deposited onto a substrate.

According to this reactive beam evaporation method, the evaporation rate can be significantly increased to 10 μm/hr.

The present invention relates to an apparatus for producing a zinc oxide film using the above-mentioned reactive beam evaporation method.

FIG. 1 is a front sectional view of an example of an apparatus for manufacturing a zinc oxide film by reactive beam evaporation, and the reactive beam evaporation method will be specifically explained below.

The inside of the bell jar 10 is maintained at a high vacuum, and oxygen gas is introduced through the intake pipe 11.

On the other hand, the zinc 13 housed in the crucible 12 is heated by the heater 14 and vaporized, and is ejected from the nozzle of the crucible 12 into the bell jar 10 .

The oxygen gas in the bell jar is activated in the plasma discharge region generated by the high-frequency discharge excitation coil 15 and becomes more likely to react with zinc.

Further, by providing the magnet 16, the discharge plasma is trapped and the density is increased, thereby increasing the activation efficiency.

Zinc oxide formed by the reaction of oxygen gas and zinc vapor is substrate 1.
7 to form a zinc oxide film on the surface.

The substrate 17 is appropriately heated by a heater 18.

As mentioned above, the characteristics of the reactive beam evaporation method are that it can vaporize a large amount of zinc, and it also forms a high-frequency discharge region to activate oxygen and promote the reaction, so that the desired zinc oxide film can be formed in a short time. It's about what you get.

In order to mass-produce zinc oxide films using the above-mentioned reactive beam deposition method, it is necessary to deposit the film onto a large number of substrates at once, or to perform the deposition while moving the substrates.

In these cases, large amounts of zinc must be evaporated, making it necessary to use multiple crucibles.

For this purpose, zinc vapor is scattered over a wide area, but in order to form a zinc oxide film, the zinc vapor must be completely reacted with oxygen.

The present invention was developed to meet the above requirements, and aims to form a discharge region over a wide range in order to supply sufficient activated oxygen to the region where zinc vapor is scattered.

Another object of the present invention is to perform efficient vapor deposition while preventing the discharge electrode from becoming an obstacle to the scattering of zinc vapor.

2 and 3 are plan views of the crucible and discharge electrode portion used in the zinc oxide film manufacturing apparatus according to the present invention.

A plurality of crucibles 22 are installed in an appropriate arrangement.

All of these crucibles are heated by heaters (not shown).

Zinc is heated, melted, further vaporized, and injected from the nozzle 30.

On the other hand, the part where zinc is injected is surrounded by a metal wire 25.

As shown in FIG. 2, the injection area of each crucible may be wrapped around, or as shown in FIG. 3, the injection areas of a plurality of crucibles may be wrapped together.

The metal wire 25 is thus formed in a shape that surrounds all the injection areas, and when connected to a high frequency power source, generates high frequency plasma discharge.

The discharge plasma at this time activates the oxygen gas and promotes the reaction with zinc.

In addition, if a magnet is appropriately provided around the metal wire 25,
It has the effect of trapping discharge plasma and can activate oxygen gas more reliably.

Since only the single metal wire 25 constitutes the electrode for high-frequency discharge, not only can the area occupied by the electrode be extremely small, but also connection and adjustment to a power source can be performed extremely easily.

Note that the shape of the metal wire is not limited to the above example, and may be any other shape as long as it surrounds the entire area where zinc is ejected.

Further, although it may be formed planarly or three-dimensionally, it is preferable to use a shape and size that does not obstruct the scattering of zinc vapor.

According to the present invention, an apparatus suitable for mass production can therefore be obtained.

Moreover, there is an advantage that zinc oxide can be deposited on the substrate without losing the injection energy of the zinc vapor.

[Brief explanation of drawings]

Figure 1 is a front sectional view of an example of a conventional device, Figures 2 and 3 are
The figure shows the crucible and electrode (metal wire) used in the device according to the present invention.
A top view of an example is shown. 22... Crucible, 25... Metal wire, 3
0...Nozzle.

Claims (1)

[Scope of utility model registration request] In a zinc oxide film manufacturing apparatus that vaporizes zinc by heating it in a crucible and reacts with activated oxygen in a high-frequency discharge region to deposit zinc oxide on a substrate, a plurality of crucibles are arranged and the high-frequency discharge 1. An apparatus for manufacturing a zinc oxide film, characterized in that the electrode is formed of a single metal wire that surrounds the entire area from which zinc vapor is ejected from a crucible.