Device for the regulation of a plasma impedance
US6860973B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 2002 |
| Grant date | Mar 1, 2005 |
| Priority date | — |
| Expiry date | May 7, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/34
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to a device for the regulation of a plasma impedance in a vacuum chamber, wherein at least one electrode is connected to an AC generator. This AC generator is a free-running [oscillator], whose frequency adjusts to the resonance frequency of the load upon which it acts. This load comprises fixed circuit elements and a variable plasma impedance. If the plasma impedance is changed, with it the resonance frequency is also changed. The plasma impedance can thus be varied by acquisition of the resonance frequency and by presetting of a reference frequency value, for example thereby that the voltage, the current, the power or the gas inflow is varied as a function of the difference between resonance frequency and reference frequency value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.