Method for obtaining uniform etch by modulating bias on extension member around radio frequency etch table
US4392932A · kind A · utility
Assignee
Inventor
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
A method for etching a semiconductor wafer on an RF etch table employs a succession of different biases on an extension member positioned adjacent the periphery of the table. The extension member is electrically conductive, but is insulated from the etch table. The extension member is positioned with respect to the periphery of the table in a manner such that the plasma sheath induced above the etch table is continued beyond the periphery of the table, thereby eliminating the focusing of ions on the edges of an item being etched on the table. As different bias voltages are applied to the extension member, different etch profiles are experienced on the semiconductor wafer. The aggregation of etch profiles produces a more uniform overall etch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.