Effective narrow band gap base transistor
US4972246A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 1988 |
| Grant date | Nov 20, 1990 |
| Priority date | — |
| Expiry date | Mar 22, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/177
Abstract
A homojunction bipolar transistor having a superlattice base region comprising alternate layers of extrinsic and intrinsic layers, with extrinsic layers being of the opposite conductivity of the emitter and collector layers of the transistor. The alternate extrinsic and intrinsic layers have substantially different doping levels providing abrupt transitions in the valence and conduction bands between layers. The abrupt transitions result in the energy band gap in the base region being effectively reduced with respect to the band gap in the emitter region. In one embodiment, the effective narrow band gap base transistor is implemented by converting a portion of the upper layers of the superlattice to a homogeneous region by heavily doping the portion to form the emitter of the transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.