Bias voltage frequency controlled angular ion distribution in plasma processing
US9520267B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 2014 |
| Grant date | Dec 13, 2016 |
| Priority date | — |
| Expiry date | Aug 25, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3065
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The angular ion distribution in plasma processing is controlled using a bias voltage frequency. In one example, a plasma containing gas ions is generated in a plasma chamber. The plasma sheath is modified using an aperture disposed between the plasma sheath and the workpiece so that the plasma sheath takes a shape above the aperture. An oscillating radio frequency bias voltage is generated and applied to a workpiece holder. The workpiece holder applies the bias voltage to the workpiece to generate a workpiece bias voltage with respect to the plasma to attract ions across the plasma sheath toward the workpiece. The aperture and the frequency of the bias voltage control an angle at which the ions are attracted toward the workpiece.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.