Plasma generating apparatus

Patent 5147493 Issued on September 15, 1992. Estimated Expiration Date:

June 12, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

2457663

2637018

Long life incandescent switching system
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Inventors

Assignee

Tokyo Electron Yamanashi Limited

Application

No. 714231 filed on 06/12/1991

US Classes:

156/345.44, Electrically coupled to a power supply or matching circuit118/723E, Having glow discharge electrodes (e.g., DC, AC, RF, etc.)204/298.06, Triode, tetrode, auxiliary electrode or biased workpiece204/298.34, Auxiliary electrode, bias means or specified power supply315/111.51Induction type

Examiners

Primary: Simmons, David A.
Assistant: Goudreau, George

Attorney, Agent or Firm

Oblon, Spivak, McClelland, Maier & Neustadt

International Class

H01L 021/00

Foreign Application Priority Data

1990-06-15 JP

Abstract

A plasma generating apparatus comprising a transformer including a primary winding connected to a high frequency power source and a secondary winding having two end terminals and a plurality of tap terminals connected between the end terminals, the transformer being adapted to deliver first and second high frequency electric powers with a phase difference of 180° from the end terminals, upper and lower electrodes disposed in a vacuum chamber so as to be opposed at a distance from each other and supplied with the first and second high frequency powers, respectively, and a power ratio selector for switching the tap terminals to select the ratio between the first and second high frequency powers supplied to the electrodes, wherein a to-be-processed object placed on the lower electrode is processed by means of plasma formed between the electrodes.