Electrostatic clamping method and apparatus
US9793149B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 2014 |
| Grant date | Oct 17, 2017 |
| Priority date | — |
| Expiry date | Feb 6, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/6833
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of electrostatically clamping a dielectric wafer to a processing table during plasma processing is described. The table has interdigitated electrodes embedded therein. The method comprises applying respective voltages of opposite first and second polarities to adjacent electrodes wherein polarization charges are induced in the wafer with opposite polarity to the respective underlying electrodes thereby electrostatically clamping the wafer to the table; and, after a predetermined time (ton), reversing the polarities of the voltages so that the polarization charges and electrostatic clamping continues. The on time (ton) of each of the first and second polarities is preselected to be The time (ts) for switching between the first and second polarities is less than the time (T1) and less than 2 seconds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.