Method and apparatus for establishing electrical contact between a wafer and a chuck
US6121783A · kind A · utility
95Cited by
2References
14Claims
0Family size
Inventors
Key dates
| Filing date | Apr 22, 1997 |
| Grant date | Sep 19, 2000 |
| Priority date | — |
| Expiry date | Apr 22, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/14
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A needle is pressed into the backside oxide of a semiconductor wafer and a voltage applied to the wafer greater than the breakdown voltage of the oxide in order to make an electrical contact with the bulk material of the wafer. A capacitor plate is provided proximate to a wafer on a chuck and a Kelvin probe is provided proximate to the wafer. A varying voltage is applied between the chuck and the capacitor plate and a voltage is monitored between the Kelvin probe and the chuck. The monitored voltage remaining constant indicates electrical contact between the chuck and the wafer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.