Method of and apparatus for igniting a plasma in an r.f. plasma processor
US5982099A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1996 |
| Grant date | Nov 9, 1999 |
| Priority date | — |
| Expiry date | Mar 29, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05H1/36
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A gas in a vacuum plasma processing chamber is ignited to a plasma by subjecting the gas to an r.f. field derived from an r.f. source having a frequency and power level sufficient to ignite the gas into the plasma and to maintain the plasma. The r.f. field is supplied to the gas by a reactive impedance element connected via a matching network to the r.f. source. The matching network includes first and second variable reactances that control loading of the source and tuning a load, including the reactive impedance element and the plasma, to the source. The value of only one of the reactances is varied until a local maximum of a function of power coupled between the source and the load is reached. The value of only the other reactance is varied until a local maximum of the function is reached. The two varying steps are then repeated as necessary.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.