Applied Materials, Inc.
Method and apparatus for actively tuning a plasma power source

Abstract:

An RF plasma generator configured to ignite and maintain a plasma from one or more processing gases is disclosed. A switch mode power supply is configured to convert a DC voltage from a DC power source to an RF voltage. A resonance circuit is configured to deliver an amount of power to an ignited plasma from the switch mode power supply. A plasma controller is configured to operate the power supply to apply an RF voltage corresponding to the amount of power to the one or more processing gases through the resonance circuit. The RF voltage increases in amplitude and decreases in frequency until the one or more processing gasses are ignited into a plasma. Responsive to detecting ignition of the plasma, the plasma controller is further configured to continuously adjust the frequency of the switch mode power supply to deliver the amount of power to the ignited plasma. The amount of power is a substantially constant amount of power.