Extreme edge uniformity control
US10665433B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 19, 2016 |
| Grant date | May 26, 2020 |
| Priority date | — |
| Expiry date | Nov 18, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/3365
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A workpiece processing apparatus allowing independent control of the voltage applied to the shield ring and the workpiece is disclosed. The workpiece processing apparatus includes a platen. The platen includes a dielectric material on which a workpiece is disposed. A bias electrode is disposed beneath the dielectric material. A shield ring, which is constructed from a metal, ceramic, semiconductor or dielectric material, is arranged around the perimeter of the workpiece. A ring electrode is disposed beneath the shield ring. The ring electrode and the bias electrode may be separately powered. This allows the surface voltage of the shield ring to match that of the workpiece, which causes the plasma sheath to be flat. Additionally, the voltage applied to the shield ring may be made different from that of the workpiece to compensate for mismatches in geometries. This improves uniformity of incident angles along the outer edge of the workpiece.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.