Voltage controller for electrostatic chuck of vacuum plasma processors
US5708250A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1996 |
| Grant date | Jan 13, 1998 |
| Priority date | — |
| Expiry date | Mar 29, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S269/903
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An r.f. excited vacuum plasma processor has a workpiece held in place by a monopolar or bipolar electrostatic chuck having an electrode that develops peak r.f. voltages over a wide amplitude range. A chuck DC power supply source is connected to the chuck. An r.f. peak detecting circuit coupled with the electrode is part of a circuit for controlling the DC voltage applied by the chuck power supply to the chuck. The control circuit supplies an unamplified replica of a DC voltage derived by the peak detecting circuit to the chuck DC power supply source via a DC circuit including only passive elements so the level of the DC voltage applied to the chuck varies in response to variations in the peak amplitude of the r.f. voltage. The peak detector includes at least several series connected diodes having electrodes polarized in the same direction or two stacks of series connected diodes. In one of the stacks, the diode electrodes are polarized in one direction and in the other stack the diode electrodes are polarized in the other direction. The diodes of the peak detecting circuit are arranged so the DC bias voltage supplied to the chuck and the peak value of the r.f. voltage developed at …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.