Automatic phase adjusting circuit for a plasma processing apparatus
US5844369A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1997 |
| Grant date | Dec 1, 1998 |
| Priority date | — |
| Expiry date | May 14, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05H1/46
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A phase adjusting circuit for adjusting phases of output powers from two high frequency power generators in a plasma processing apparatus comprises first and second synthesizing circuits for generating first and second high frequency signals of a predetermined waveform with frequencies of f0 and f0.+-..DELTA.f (.DELTA.f<<f0), a phase difference detection circuit for detecting a phase difference between detection signals of plate electrodes, a third waveform synthesizing circuit for generating a high frequency signal with frequency and waveform same as the first frequency signal which has a phase determined from a phase error between a set phase difference and an output from the phase difference detection circuit and a phase adjusting circuit which determines output powers of the two high frequency power generators base on outputs of the first and third waveform synthesizing circuits.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.