Apparatus and method for holding a wafer
US8917489B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 11, 2012 |
| Grant date | Dec 23, 2014 |
| Priority date | — |
| Expiry date | Oct 11, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67288
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An apparatus and a method for holding a wafer are provided in this disclosure. The wafer holding apparatus includes: an electrostatic chuck, the electrostatic chuck having a plurality of concentric zones; a plurality of power supply units, each adapted for applying a voltage to one of the zones of the electrostatic chuck independently; and a control unit, adapted for controlling each of the power supply units independently to start or stop applying the voltage to a corresponding zone of the electrostatic chuck. Surface flatness is improved when the wafer is chucked on the wafer holding apparatus according to the disclosure, and the risk of particle contamination can be reduced when the wafer is flattened and gets back into warpage from flatness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.