Electrostatic dechucking method and apparatus for dielectric workpieces in vacuum processors
US6125025A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1998 |
| Grant date | Sep 26, 2000 |
| Priority date | — |
| Expiry date | Sep 30, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T279/23
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A glass workpiece processed in a vacuum plasma processing chamber is dechucked from a monopolar electrostatic chuck by gradually reducing the chucking voltage during processing while maintaining the voltage high enough to clamp the workpiece. The chucking voltage during processing is controlled in response to flow rate of a heat transfer fluid flowing to the chuck to maintain the chucking force and the flow rate approximately constant. A reverse polarity voltage applied to the chuck at the end of processing assists in dechucking. The workpiece temperature is maintained at a high value at the end of processing to assisting in dechucking. Peak current flowing through the chuck during workpiece lifting from the chuck controls the amplitude and/or duration of the reverse polarity voltage during the next dechucking operation. An inert plasma in the chamber removes residual charge from the workpiece after workpiece lifting from the chuck.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.