Step down dechucking
US8164879B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 2009 |
| Grant date | Apr 24, 2012 |
| Priority date | — |
| Expiry date | Jun 11, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/6833
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method and an apparatus for dechucking an electrostatic chuck are disclosed. The gas escapes through an opening between a wafer and a chuck in each stage of a multi-stages process. In each stage, during at least a portion of the stage, the chucking voltage is reduced to a value less than the least threshold voltage needed for holding the wafer, so that the wafer is pushed away from the chuck by the gas. Hence, the gas can escape from an opening between the wafer and the chuck, thereby increasing the dechucking rate. By controlling the decrement and/or the duration of the reduced voltage, any potential damages due to the pushed-away wafer can be minimized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.