The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 10, 1999
Filed:
Jan. 15, 1998
Shuitsu Fujii, Fukuyama, JP;
Adtec Corporation Limited, Hiroshima, JP;
Abstract
The invention provides an impedance matching and power control system not resorting to mechanical control for a device for high frequency plasma treatment. An impedance matching unit 14 inserted in the terminal end of a power feed line 3 extending from a high frequency power oscillator 1 to a plasma chamber 2 comprises phase detecting means 17, a load-associated detector 19 having the function of detecting voltage, current, and phase angle, and an arithmetic and output section 21, whereby the impedance matching unit delivers a frequency control signal corresponding to the detected phase and a power signal representing the consumed power of the plasma chamber as calculated from the voltage, current and phase angle. The high frequency power oscillator comprises an oscillation control section 24 for controlling the oscillation frequency thereof according to said frequency control signal, and an output control section including a summing amplifier 25 which receives an external set power signal and the detected power signal to find the difference between the two values of power, thus controlling its own output power according to the difference.