Wafer chucking monitor using high frequency injected AC signal
US11562918B2 · kind B2 · utility
1Cited by
4References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 7, 2021 |
| Grant date | Jan 24, 2023 |
| Priority date | — |
| Expiry date | Jul 31, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02N13/00
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
This disclosure describes systems, methods, and apparatus for non-invasive wafer chuck monitoring using a low voltage AC signal injected into a high voltage DC chucking voltage provided to a wafer chuck. Monitoring the injected signal can provide insight into the wafer chucking state and remedial actions, such as realignment of the wafer with the wafer chuck, can be carried out. Because of the low voltage nature of the AC signal, wafer chuck monitoring can be performed without influencing chucking performed by the higher voltage DC chucking voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.