Inert gas purge for the multilayer poly gate etching improvement
US5188980A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 6, 1992 |
| Grant date | Feb 23, 1993 |
| Priority date | — |
| Expiry date | Jul 6, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32137
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process for dry etching a multilayer tungsten silicide or other metal silicide polysilicon gate structure of an integrated circuit is achieved. A mixture of chlorine and helium gases is flowed into a vacuum chamber and a radio frequency is applied for etching the silicide layer. The chlorine gas flow is stopped after the etching of the tungsten silicide is completed and the vacuum chamber is purged with helium. The chlorine and helium gas flow is resumed to complete the etching of the polysilicon multilayer portion with a mixture of chlorine and helium gases. No undercutting of the tungsten silicide is experienced using this process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.