Methods and apparatus for dechucking wafers
US11171030B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 2019 |
| Grant date | Nov 9, 2021 |
| Priority date | — |
| Expiry date | Jun 9, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67253
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for dechucking a wafer from a surface of an electrostatic chuck (ESC). In some embodiments, a method comprises reducing a pressure of a gas applied to a backside of the wafer to approximately zero psi; reducing a downward pressure in a cylinder bore of a lifting actuator to approximately atmospheric pressure while a processing volume of the processing chamber is in a vacuum state to create a constant upward force on the wafer, the constant upward force less than a breaking force of the wafer; and sweeping a voltage applied to the ESC to dechuck the wafer; and monitoring a sensor on the lifting actuator that is interposed between a chucking position of the lifting actuator and a transfer position of the lifting actuator to detect when the wafer is dechucked.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.