Method of etching WSi.sub.x films
US5492597A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 13, 1994 |
| Grant date | Feb 20, 1996 |
| Priority date | — |
| Expiry date | May 13, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32137
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention teaches a method for etching a tungsten silicide (WSi.sub.x) film overlying a polysilicon film in an enclosed chamber during a semiconductor fabrication process, by the steps of: providing a patterned mask overlying the WSi.sub.x film thereby providing exposed portions of the WSi.sub.x film; presenting an etchant chemistry comprising NF.sub.3 and HeO.sub.2 to the exposed portions of the WSi.sub.x film at a temperature ranging from -20.degree. C. to 100.degree. C., thereby etching away the exposed portions of the WSi.sub.x film and simultaneously etching substantially vertical sidewalls in the WSi.sub.x film, the etching continues into the polysilicon film, thereby forming a WSi.sub.x /polysilicon stack having substantially vertical sidewalls.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.