Inductive plasma processor having coil with plural windings and method of controlling plasma density
US7096819B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 2001 |
| Grant date | Aug 29, 2006 |
| Priority date | — |
| Expiry date | May 27, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/321
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An inductive plasma processor includes a multiple winding radio frequency coil having plural electrically parallel, spatially concentric windings (1) having different amounts of RF power supplied to them, and (2) arranged to produce electromagnetic fields having different couplings to different regions of plasma in the chamber to control plasma flux distribution incident on a processed workpiece. The coil is powered by a single radio frequency generator via a single matching network. Input and output ends of each winding are respectively connected to input and output tuning capacitors. In a first embodiment, the location of maximum inductive coupling of the radio frequency to the plasma and the current magnitude in each winding are respectively mainly determined by values of the output and input capacitors. By adjusting all the input and output capacitors simultaneously, the current to a winding can be varied while the current to the other winding can be maintained constant as if these windings were completely de-coupled and independent. Therefore, the capacitors can control the plasma density in different radial and azimuthal regions. In another embodiment, a relatively low freque…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.