Method of selectively etching silicon dioxide with SF.sub.6 /nitriding component gas
US4465552A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 11, 1983 |
| Grant date | Aug 14, 1984 |
| Priority date | — |
| Expiry date | Aug 11, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31116
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A gaseous mixture of SF.sub.6 and a nitriding component such as NH.sub.3 is disclosed as an effective selective SiO.sub.2 etchant for use in either the plasma or reactive ion etch process. By adding NH.sub.3 to the SF.sub.6, which is a known effective plasma etchant for silicon or poly-silicon, the silicon etch rate decreases while the oxide rate is effectively constant. At about 14% nitriding gas component, the rates are equivalent and for higher nitriding gas fractions, the silicon dioxide rate dominates. The optional addition of an inert diluent gas did not substantially change these results. The addition of hydrogen to the gaseous SF.sub.6 /nitriding component mixture retards the etch rate on silicon still further and may increase the selectivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.