US 4,379,743 AGranted

Sputtering apparatus comprising control means for preventing impurity gases from entering a sputtering chamber

AssigneeAnelva Corporation

InventorsMasashi Nakatsukasa, Nobuyuki Takahashi

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Abstract

In a sputtering apparatus comprising a main chamber for carrying out sputtering and a preliminary chamber for preliminarily processing a substrate prior to sputtering, a gate valve interposed between the chambers is opened with the pressure in the preliminary chamber is reduced lower than that in the main chamber after completion of the preliminary processing. The pressure reduction is carried out by reducing supply of a gas into the preliminary chamber by the use of a pressure control system coupled to the preliminary chamber. Preferably, the supply of the gas is bypassed through a valve to an exhausting system for the preliminary chamber. Alternatively, the pressure in the main chamber is made higher than that in the preliminary chamber after completion of the preliminary processing by squeezing an evacuation system for the main chamber to reduce the rate of evacuation. Supply of the gas into the preliminary chamber and evacuation of the main chamber may be simultaneously reduced.

Claims4

Dependent claims

A sputtering apparatus comprising a main chamber defining a main hollow space, first means for holding a substrate in said main hollow space, second means for sputtering a predetermined material onto the substrate held by said first means to form a layer of said material, a preliminary chamber defining a preliminary hollow space, third means for carrying out preliminary processing of a substrate in said preliminary hollow space, valve means for selectively isolating said main and said preliminary hollow spaces from each other and making said main and said preliminary hollow spaces communicate with each other for transfer of the substrate from said third means to said first means, first pressure controlling means coupled to said main hollow space for controlling a first pressure in said main hollow space, second pressure controlling means coupled to said preliminary hollow space for controlling a second pressure in said preliminary hollow space, wherein the improvement comprises:

control means coupled to said valve means and at least to a selected one of said first and said second pressure controlling means for controlling said selected pressure controlling means with reference to completion of said preliminary processing and for opening said valve means after said second pressure becomes less than said first pressure.

Dependencies are inferred from the claim text.