Plasma source with process nonuniformity improved using ferromagnetic cores
US5994236A · kind A · utility
52Cited by
8References
11Claims
0Family size
Inventor
Key dates
| Filing date | Jan 23, 1998 |
| Grant date | Nov 30, 1999 |
| Priority date | — |
| Expiry date | Jan 23, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/3266
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention uses the placement of ferromagnetic cores to improve the nonuniformity of plasma processing and to increase the energy transfer efficiency of plasma sources which couple energy to a plasma through the use of radio frequency current flowing through a coil adjacent to a dielectric window. In addition, eddy current conductive elements can be used either alone or in combination with ferromagnetic cores to increase the nonuniformity adjustment range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.