Heterojunction bipolar transistor having low electron and hole concentrations in the emitter-base junction region
US5508536A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1994 |
| Grant date | Apr 16, 1996 |
| Priority date | — |
| Expiry date | Apr 7, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D10/821
Abstract
The present invention provides a heterojunction bipolar transister includes: a collector layer, a base layer, an emitter layer, a transition layer formed between the base layer and the emitter layer, a collector electrode connected to the collector layer, a base electrode connected to the base layer, and an emitter electrode connected to the emitter layer, wherein the emitter layer and the transition layer are formed of a composition including elements forming the base layer and at least one element different from the elements forming the base layer, a composition of the different element in the transition layer at the emitter side is substantially equal to that of the emitter layer, a composition of the different element in the transition layer at the base side is smaller than that of the emitter side and varies abruptly towards the base layer, and the composition of the transition layer gradingly varies from the base side to the emitter side.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.