Electrostatic chuck with radiative heating
US8987639B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 5, 2012 |
| Grant date | Mar 24, 2015 |
| Priority date | — |
| Expiry date | May 9, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/68757
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An electrostatic chuck is formed using materials that are optically transparent to a range of frequencies, such as infrared radiation. The invention discloses several methods for achieving optical transparency. The chuck electrode can be formed having a mesh pattern designed with a specific open area percentage to provide adequate wafer clamping force while still allowing sufficient levels of infrared radiation to pass through. Alternatively, the chuck electrode can also be made from a transparent conductive film. A workpiece is disposed on one surface of the chuck, and a radiative heat source is positioned on the opposite side of the chuck. A reflector plate may be used to reflect the infrared radiation toward the chuck and the wafer. The spacing of the radiation sources and the shape of the reflector plate may be modified to focus more radiation on a particular portion of the workpiece if desired.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.