Control of wafer bow in multiple stations
US11823928B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 2021 |
| Grant date | Nov 21, 2023 |
| Priority date | — |
| Expiry date | Oct 29, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/3321
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A system for controlling of wafer bow in plasma processing stations is described. The system includes a circuit that provides a low frequency RF signal and another circuit that provides a high frequency RF signal. The system includes an output circuit and the stations. The output circuit combines the low frequency RF signal and the high frequency RF signal to generate a plurality of combined RF signals for the stations. Amount of low frequency power delivered to one of the stations depends on wafer bow, such as non-flatness of a wafer. A bowed wafer decreases low frequency power delivered to the station in a multi-station chamber with a common RF source. A shunt inductor is coupled in parallel to each of the stations to increase an amount of current to the station with a bowed wafer. Hence, station power becomes less sensitive to wafer bow to minimize wafer bowing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.