Method of manufacturing bipolar semiconductor device
US4782030A · kind A · utility
32Cited by
6References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 7, 1987 |
| Grant date | Nov 1, 1988 |
| Priority date | — |
| Expiry date | Jul 7, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/011
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A laminated film made of a first insulating film and a second insulating film having a selectivity of etching condition to the first insulating film is selectively formed on a first conductivity type semiconductor substrate to use the substrate under the laminated film as a base and emitter active region forming region. The laminated film remains until an anisotropically dry etching step is finished to prevent the base and emitter active region from damaging due to an etching atmosphere at anisotropically dry etching time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.