Plasma processing methods and apparatus
US6261375A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 17, 2000 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Jul 17, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/68
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
To move an article in and out of plasma during plasma processing, the article is rotated by a first drive around a first axis, and the first drive is itself rotated by a second drive, so that the article enters the plasma at different angles for different positions of the first axis. The plasma cross-section at the level at which the plasma contacts the article is such that those points on the article that move at a greater linear velocity (due to being farther from the first axis) move longer distances through the plasma. As a result, the plasma processing time becomes more uniform for different points on the article surface. The direction of rotation of the first and/or second drive changes during processing to improve processing uniformity. The article is allowed to be processed with the plasma only during one-half of each revolution of the second drive. In the other half of each revolution, the processing is substantially prevented by increasing the second drive velocity as the article is carried through the plasma.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.