Radio frequency etch table with biased extension member
US4392938A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1981 |
| Grant date | Jul 12, 1983 |
| Priority date | — |
| Expiry date | Nov 12, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/34
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An RF etch table has a biased extension member positioned adjacent its periphery. The extension member is electrically conductive, but is insulated from other conductive members in the system. The extension member is positioned with respect to the periphery of the table in a manner such that the boundary of the plasma induced above the etch table is continued beyond the periphery of the etch table, thereby eliminating the focusing of ions onto the edges of an item being etched on the table. The potential impressed upon the extension member produces a dark space above its surface having a sufficient height so that the horizontal configuration of the sheath above the etch table is continued beyond its edges. More uniform etching is accomplished.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.