Patent · US Expired

System for igniting and controlling a wafer processing plasma

US4557819A · kind A · utility

44Cited by
9References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 20, 1984
Grant dateDec 10, 1985
Priority date
Expiry dateJul 20, 2004

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01J37/3266
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A circuit for impedance matching an RF source to a plasma load comprises an impedance magnitude control shunted with a parallel-resonant tank circuit to provide a phase control. A DC-blocking capacitor and RF filter are used to monitor the self-bias voltage on a workpiece in the plasma. An ignition control is used to provide prompt ignition of the plasma and a rotating magnet is used to stabilize the plasma.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.