Anisotropic etch method for a sandwich structure
US5013398A · kind A · utility
72Cited by
6References
17Claims
0Family size
Assignee
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Key dates
| Filing date | May 29, 1990 |
| Grant date | May 7, 1991 |
| Priority date | — |
| Expiry date | May 29, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31116
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A plasma etch process to anisotropically etch a sandwich structure of silicon dioxide, polycrystalline silicon, and silicon dioxide "in situ", that is, in a single etch chamber. The silicon dioxide is etched using a SF.sub.6 /CHF.sub.3 /He chemistry. The polycrystalline silicon is etched using a HBr/He chemistry. A non-erodible cathode is used. Tungsten silicide may replace the polycrystalline silicon. Silicon nitride may replace the silicon dioxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.