Method of fabricating a high-frequency bipolar transistor structure utilizing permeation-etching
US4347654A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 1980 |
| Grant date | Sep 7, 1982 |
| Priority date | — |
| Expiry date | Jun 18, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/084
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of fabricating a high-frequency bipolar transistor structure wherein the emitter, higher impurity concentration base, and lower impurity concentration base regions are defined in a single masking operation. Permeation etching is used to etch regions of an oxide layer under a layer of resist which defines regions of the higher impurity concentration thereby simultaneously defining the emitter and lower impurity concentration base regions. The higher impurity concentration base regions are formed by ion implantation of impurities through the unetched oxide regions. The resist is then removed and the lower impurity concentration base and emitters are formed through the resulting opening in the oxide. This results in the self-aligning of the emitter regions with respect to the base regions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.