Method of etching silicon nitride
US5472562A · kind A · utility
16Cited by
2References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 5, 1994 |
| Grant date | Dec 5, 1995 |
| Priority date | — |
| Expiry date | Aug 5, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32133
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Etch baths having phosphoric acid, nitric acid and hydrofluoric acid and used to selectively remove silicon nitride or silicon with respect to silicon oxide have enhanced initial selectivity when silicon is added to the initial bath. The silicon may be added in the form of soluble silicon compounds such a hexafluorosilicic acid or ammonium fluorosilicate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.