JPH03219069A - Method for cleaning vacuum vessel - Google Patents

Abstract

PURPOSE:To clean a vessel by removing dust, etc., in the vessel by forcedly exhausting gas in the vessel while introducing the clean gas in the vacuum vessel. CONSTITUTION:At the time of introducing the gas into the vessel in order to return the pressure of vacuum vessel to the pressure of atmosphere, the dust stuck to wall surface, etc., in the vessel is blown up. The clean gas is introduced in the vessel while forcedly and quickly exhausting the gas in the vessel whose pressure is returned back to the atmospheric pressure and the dust is sucked and removed while holding the reduced pressure condition of the vessel. By this method, even if a detector for measuring the dust is inserted from window during cleaning, the dust is not blown out and the substrate, etc., prepared outside of the vessel is not contaminated. By cleaning the substrate introducing vessel, etc., in sputtering apparatus with this method, the operation of apparatus can be accelerated.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for cleaning a vacuum chamber.

Specifically, the present invention relates to a cleaning method for cleaning the inside of a vacuum chamber (reduced pressure chamber) by removing dust and the like in an apparatus for forming a thin film in a vacuum chamber (reduced pressure chamber) using sputtering, vacuum evaporation, or the like.

[Conventional technology and its problems]

Various methods are known as techniques for forming thin films in vacuum, such as sputtering, vacuum deposition, ion blasting, and chemical vapor deposition. This type of technology is often applied to the manufacture of precision articles, and requires thin films with extremely high precision. Therefore, even if a small amount of dust remains in the vacuum chamber, this poses a serious problem of product defects. Therefore, it has been desired to develop a method for quickly and completely cleaning the inside of this type of vacuum chamber. As one of the cleaning methods, a method has been considered in which lean air is supplied by a blower and forced out to the exhaust system, as disclosed in, for example, Japanese Patent Laid-Open No. 196367/1983. However, with this method, for example, a detection device is inserted to check for the presence of dust during cleaning, so when the confirmation window is opened, the internal pressure is high and the gas inside the tank blows out, causing the entrained dust to spread to the surroundings. There were problems such as defeat and contamination.

[Means for Solving the Problems] As a result of various studies on the problems of the conventional technology as described above, the present inventors have found that the problems can be solved by circulating clean gas while maintaining the inside of the tank in a reduced pressure state. This discovery led to the completion of the present invention.

That is, the gist of the present invention resides in a method for cleaning a vacuum chamber, which is characterized by introducing clean gas into the vacuum chamber and forcibly suctioning and exhausting the gas within the chamber. .

To form a thin film by sputtering etc. in a vacuum chamber, the substrate for thin film formation must be moved from outside the chamber (atmosphere) to inside the chamber (vacuum).
There is a step of introducing the thin film into the tank, a film forming step, and a step of removing the thin film from the tank after forming the thin film, and the vacuum tank is repeatedly placed in a vacuum state and a normal pressure state.

In particular, when gas is introduced into the vacuum tank to return it to atmospheric pressure, dust adhering to the walls of the tank rises and becomes a source of contamination.

The method of the present invention is to quickly forcibly exhaust the gas in the vacuum chamber that has returned to atmospheric pressure as described above, introduce clean gas into the chamber, and suction and remove dust while maintaining a reduced pressure state. By doing this, for example, even if a detector for measuring dust is inserted through a window during cleaning, dust will not blow out and contaminate the substrate prepared outside the tank.

〔Example〕

EXAMPLES The method of the present invention will be specifically explained below by way of examples.

Example 1 200mmX corresponding to the base material introduction part of the sputtering device
A vacuum chamber with an internal space of 500 mm x 800 mm was once evacuated to 5 x 10-5 torr, then clean air was introduced and the pressure was returned to atmospheric pressure in 5 seconds. As measured by a counter, the cleanliness was class 15,000 (cleanliness refers to the number of dust particles per lft").

Next, when the exhaust system was activated and clean air passed through a 0.03μ filter was supplied, the cleanliness level quickly decreased to class 5.

By operating the exhaust system, the pressure inside the tank was slightly reduced, and the surrounding air was sucked in, so the dust in the tank was not blown out into the surrounding area.

〔Effect of the invention〕

According to the method of the present invention, the dust in the vacuum chamber can be quickly discharged, and the surrounding environment is not contaminated.

Therefore, by cleaning the base material introduction tank of the sputtering apparatus using this method, it is possible to increase the speed, which is very suitable for practical use.

Claims (1)

[Claims] (1) A method for cleaning a vacuum chamber, which comprises introducing clean gas into the vacuum chamber and forcibly suctioning and exhausting the gas within the chamber.