Plasma cleaning of a CVD or etch reactor using a low or mixed frequency excitation field
US5882424A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 1997 |
| Grant date | Mar 16, 1999 |
| Priority date | — |
| Expiry date | Jan 21, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/32165
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for cleaning the interior of a vacuum chamber of a plasma reactor which includes introducing an etchant gas through inlet ports into the vacuum chamber and applying RF power to a RF plasma excitation apparatus so as to ignite and sustain a plasma within the chamber. The frequency of the RF signal is less than 1 MHz. Alternately, an apparatus and method for cleaning the aforementioned vacuum chamber where at least two different RF power signals can be employed. In one embodiment of this alternate method the step of applying RF power involves providing a first and second RF signal, where each signal exhibits a different frequency. The first RF signal is of a higher frequency and provided to ignite a plasma within the chamber, and thereafter terminated, whereas the second RF signal is of a lower frequency, less than 1 MHz, and provided to sustain the plasma. In another embodiment, the step of applying RF power again comprises providing separate RF signals, where each signal exhibits a different frequency. However, in this embodiment, the signals are used to generate a mixed frequency RF excitation field from the RF plasma excitation apparatus to ignite and sust…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.