Method of manufacturing a silicon/silicon germanium heterojunction bipolar transistor
US5897359A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1997 |
| Grant date | Apr 27, 1999 |
| Priority date | — |
| Expiry date | Dec 9, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D10/891
Abstract
There is disclosed a method of manufacturing a silicon/silicon germanium heterojunction bipolar transistor having a good conformity and an improved speed characteristic, which includes the steps of sequentially laminating an underlying nitride film, an oxide film, a polycrystalline silicon film and an upper nitride on a semiconductor substrate on which devices are separated and a collector is formed; sequentially etching said upper nitride film and said polycrystalline silicon film using the emitter as a mask, and then forming a side wall nitride film; selectively wet-etching said oxide film to form a side base linker opening; burying said base linker opening with a polycrystalline silicon; oxidizing said polycrystalline silicon film buried into said base linker opening and then removing said oxide film by means of the selective wet-etch process; removing said upper nitride and then forming a silicon/silicon germanium film as a base film on the exposed thereof; and forming an emitter said silicon/silicon germanium film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.