System and method of sensing and removing residual charge from a processed wafer
US8111499B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 17, 2009 |
| Grant date | Feb 7, 2012 |
| Priority date | — |
| Expiry date | Mar 19, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/14
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Systems and methods for removing residual charge from a processed wafer are described. Removal of residual charge eliminates de-chucking failure that may break or damage the wafer. Residual charge is removed by applying a reverse polarity discharging DC voltage to an electrode embedded in an electrostatic chuck (ESC) supporting the wafer, and providing an outlet to the residual charge to ground via a lift pin assembly. Lift pin assembly is kept at the same potential with respect to a pedestal of the ESC to avoid sparking during the application of RF power to generate plasma. A residual charge sensor is included to sense and measure the amount of residual charge, so that the parameters of the reverse polarity discharging voltage can be adjusted in a subsequent de-chucking operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.