Methods and apparatus for controlling ion energy and plasma density in a plasma processing system
US6174450A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1997 |
| Grant date | Jan 16, 2001 |
| Priority date | — |
| Expiry date | Apr 16, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/3299
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A plasma processing system includes a plasma reactor, a first power circuit, a second power circuit and a feedback circuit. The first power circuit supplies a first radio frequency (rf) energy to the plasma reactor that is suitable for creating a direct current bias on a workpiece positioned within a plasma chamber. The second power circuit supplies a second rf energy to the plasma reactor that is suitable for striking a plasma within the plasma chamber. The feedback circuit is coupled to control the first power circuit by detecting at least one parameter associated with the first rf energy and providing a feedback control signal to the first power circuit. The first power circuit adjusts the first rf energy so that a level of energy of the ionized particles within the plasma chamber is substantially controlled via the direct current bias created by the first rf energy. A second feedback circuit can also be provided to control the second power circuit so that a level of plasma density within the plasma chamber is substantially controlled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.