Method of manufacturing semiconductor device
US5204276A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 24, 1991 |
| Grant date | Apr 20, 1993 |
| Priority date | — |
| Expiry date | Jan 24, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/124
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
In the method of manufacturing a semiconductor device, a buffer oxide film, an oxidation-resistant film and a first poly-Si film containing a p-type impurity are successively formed to form a laminate structure on the n-type collector region, followed by forming a protective oxide film by CVD. Then, an opening portion reaching the oxidation-resistant film is formed, followed by forming a second protective insulation film to cover the surface of the first poly-Si film exposed at the side wall of the opening portion. The oxidation-resistant film is excessively etched using the protective insulation films as an etching mask so as to expose the buffer oxide film and to form a bore below the first poly-Si film. The exposed buffer oxide film is removed, followed by filling the bore with a second poly-Si film. Then, a heat treatment is performed under an oxidative atmosphere to form a thermal oxide film covering the surface of the second poly-Si film. At the same time, the p-type impurity contained in the first poly-Si film is diffused through the second poly-Si film into the collector region to form a p-type outer base region. Further, a p-type inner base region, n-type emitter region an…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.