Dry etching method
US5318668A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 1992 |
| Grant date | Jun 7, 1994 |
| Priority date | — |
| Expiry date | Oct 20, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31116
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The invention provides an improved dry etching method for selectively etching a silicon nitride layer 3 formed on the surface of a SiO.sub.2 layer 2 formed on a p-type semiconductor substrate, the method comprising the steps of supplying a mixed gas of HBr and ClF.sub.3 to a reaction chamber wherein SiBr.sub.4, caused, during the dry etching, by a reaction of the silicon nitride layer 3 and the HBr contained in the mixed gas, partly deposits on an etching wall of the p-type semiconductor substrate 1 while at the same time an excess of the SiBr.sub.4 reacts, between the p-type semiconductor substrate 1 and a wall of the reaction chamber, with the ClF.sub.3 contained in the mixed gas to produce a fluoride. The fluoride thus produced can be easily discharged to the outside, since it is more volatile.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.