JPH03219068A - Method for introducing base material into vacuum vessel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for introducing a substrate into a vacuum chamber. For more information,
In an apparatus for forming a thin film in a vacuum chamber (reduced pressure chamber) using sputtering, vacuum evaporation, etc., the present invention relates to a method for introducing a substrate for forming a thin film into the chamber so as not to be contaminated by dust or the like in the vacuum chamber.

[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 Application 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 scattering and adhering to a thin film forming substrate prepared in advance near the tank, causing contamination.

[Means to solve the problem]

As a result of various studies on the problems of the conventional technology as described above, the present inventors discovered that the problems could be solved by circulating clean gas while maintaining the inside of the tank in a reduced pressure state, and completed the present invention. reached.

That is, the gist of the present invention is that when introducing a substrate for forming a thin film into a vacuum chamber, the vacuum chamber is forcibly sucked and exhausted while introducing clean gas into the vacuum chamber. A method for introducing a vacuum chamber into a vacuum chamber, which is characterized by forming an air flow from outside the vacuum chamber toward the inside of the vacuum chamber at the inlet for introducing the substrate, and introducing the substrate into the vacuum chamber while maintaining this air flow. It depends on the method of introducing the base material.

In order to form a thin film by sputtering etc. in a vacuum chamber, the substrate for thin film formation must be placed outside the chamber (at atmospheric angle or 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 introducing a substrate for forming a thin film into a vacuum chamber, it is necessary to introduce gas into the chamber to return the vacuum chamber to atmospheric pressure, which may cause it to stick to the walls of the chamber, etc. In some cases, the dust that was being used may fly up and adhere to the surface of the base material.

The method of the present invention promptly forcibly exhausts the dust-containing gas in the vacuum chamber that has returned to atmospheric pressure and introduces clean gas into the chamber, thereby removing the substrate for the next thin film formation. To provide a method for rapidly introducing a substance into a vacuum chamber without contaminating it.

To do this, when introducing the substrate for thin film formation into the vacuum chamber, clean gas is introduced into the vacuum chamber and the gas inside the chamber is forcibly sucked and exhausted. An air flow from the outside of the vacuum chamber toward the inside of the vacuum chamber is formed at the inlet. If you maintain this air flow, place the base material in this air flow, and introduce the base material into the tank according to the air flow,
The base material is always surrounded by a clean air flow and is not contaminated by dust.

The clean gas introduced into the vacuum chamber is preferably provided with a gas introduction pipe or the like in the vacuum chamber, but it is also possible to introduce only the clean gas from the base material introduction inlet.

In addition, if the airflow generated at the inlet for introducing the substrate from outside the vacuum chamber to the inside of the vacuum chamber is too fast, it will become turbulent and kick up dust, so we generate an airflow at a slow speed to maintain laminar flow. It is desirable to do so.

The speed of the airflow can be easily controlled by adjusting the exhaust volume and the amount of clean gas introduced from the gas introduction pipe.

〔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 ns was once evacuated to 5 x 10-' torr, then clean air was introduced and the pressure was returned to atmospheric pressure in 5 seconds.The introduced air flow caused the dust in the layer to fly up. The cleanliness is class 1500 as measured by a dust counter.
(Cleanliness refers to the number of dust particles per 1 ft3.)

Then, the exhaust system was activated (3 m'/min),
and supplies clean air through a 0.03μ filter (
2m3/min) However, the cleanliness level quickly decreased to class 5.

Due to the operation of the exhaust system, there is a slight depressurization inside the layer, and the inlet of the vacuum chamber (200mm x 500M)
When the tank was opened, a gentle air flow was generated into the tank.

When the base material was introduced following this air flow and a thin film was formed by sputtering, no defects in the thin film that appeared to be caused by dust were observed.

[Effects of the Invention] According to the method of the present invention, the dust in the vacuum chamber can be quickly discharged, and the substrate can be introduced into the chamber without contaminating the substrate. It became. Therefore, product defects caused by dust in sputtering equipment and the like are eliminated, which is very effective in practice.

Claims (1)

[Claims] (1) When introducing the base material for thin film formation into the vacuum chamber,
By introducing clean gas into the vacuum chamber and forcibly suctioning and exhausting the gas inside the chamber, an air flow from outside the vacuum chamber toward the inside of the vacuum chamber is created at the inlet for introducing the substrate into the vacuum chamber. A method for introducing a base material into a vacuum chamber, which is characterized by introducing the base material into the vacuum chamber while maintaining this air flow.