Sputtering method for fabricating thin film
First Claim
1. A method for sputtering a material on an object by a glow discharge generated in a sputtering chamber, said method comprising the steps of:
- a) placing an object in a sputtering chamber having a target made of material to be sputtered on said object therein, and evacuating the sputtering chamber;
b) injecting a gas into said sputtering chamber, and increasing the pressure in said sputtering chamber to a first pressure sufficient to ignite said glow discharge;
c) decreasing the flow rate of said injection gas, and thus decreasing the pressure in said sputtering chamber to a second pressure such that said glow discharge cannot be ignited but can be maintained for a limited time if the glow discharge has previously been ignited;
d) before said glow discharge extinguishes, increasing the flow rate of said injection gas, and thus increasing the pressure in the sputtering chamber to said first pressure to at least reinforce the glow discharge; and
e) repeatedly varying the flow rate of the injection gas, and varying the pressure in the sputtering chamber as aforesaid to maintain said glow discharge and sputtering therein.
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Accused Products
Abstract
A method for sputtering by a glow discharge in gas is disclosed. The sputtering chamber is evacuated by a pump with a high speed, and the flow rate of the gas injected into the chamber is varied periodically between a high flow rate and a low flow rate. During the high flow rate, the discharge is ignited. The glow discharge is sustained during the low flow rate injection period, and when the pressure becomes too low to maintain a stable discharge, the flow rate is again increased to ignite or reinforce the electric discharge. In such a manner, the flow rate of the injection gas is periodically alternated between a high and a low injection rate. The sputtering is mostly done at the lower injection rates, and the evacuation speed is kept always high. Accordingly, contamination otherwise caused by residual gas is prevented, and a high grade sputtered film is obtained. By operating in this manner, the gas consumption is reduced and the life of the cryogenic pump, used for evacuating the sputtering chamber, is prolonged, and hence the on line operation of the sputtering device is improved.
77 Citations
7 Claims
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1. A method for sputtering a material on an object by a glow discharge generated in a sputtering chamber, said method comprising the steps of:
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a) placing an object in a sputtering chamber having a target made of material to be sputtered on said object therein, and evacuating the sputtering chamber; b) injecting a gas into said sputtering chamber, and increasing the pressure in said sputtering chamber to a first pressure sufficient to ignite said glow discharge; c) decreasing the flow rate of said injection gas, and thus decreasing the pressure in said sputtering chamber to a second pressure such that said glow discharge cannot be ignited but can be maintained for a limited time if the glow discharge has previously been ignited; d) before said glow discharge extinguishes, increasing the flow rate of said injection gas, and thus increasing the pressure in the sputtering chamber to said first pressure to at least reinforce the glow discharge; and e) repeatedly varying the flow rate of the injection gas, and varying the pressure in the sputtering chamber as aforesaid to maintain said glow discharge and sputtering therein. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification