Method of etching WSi.sub.x films
AssigneeMicron Semiconductor, Inc.
InventorDavid J. Keller
Life of this patent
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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.
Claims20
A method for etching a tungsten silicide (WSi.sub.x) film in an enclosed chamber during a semiconductor fabrication process, said method comprising the steps of:
- providing a patterned mask overlying said WSi.sub.x film thereby providing exposed portions of said WSi.sub.x film;
- presenting an etchant chemistry comprising NF.sub.3 and HeO.sub.2 to said exposed portions of the WSi.sub.x film at a temperature ranging from -20.degree. C. to 100.degree. C., thereby etching away said exposed portions of said WSi.sub.x film and simultaneously etching substantially vertical sidewalls in said WSi.sub.x film.
A method for etching a tungsten silicide (WSi.sub.x) film overlying a polysilicon film in an enclosed chamber during a semiconductor fabrication process, said method comprising the steps of:
- providing a patterned mask overlying said WSi.sub.x film thereby providing exposed portions of said WSi.sub.x film;
- presenting an etchant chemistry comprising NF.sub.3 and HeO.sub.2 to said exposed portions of the WSi.sub.x film at a temperature ranging from -20.degree. C. to 100.degree. C., thereby etching away said exposed portions of said WSi.sub.x film and simultaneously etching substantially vertical sidewalls in said WSi.sub.x film, said etching continues into said polysilicon film, thereby forming a WSi.sub.x /polysilicon stack having substantially vertical sidewalls.
Dependencies are inferred from the claim text.