Wide band gap bipolar transistor with reduced thermal runaway
US6989581B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 23, 2002 |
| Grant date | Jan 24, 2006 |
| Priority date | — |
| Expiry date | Dec 23, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/85
Abstract
A bipolar transistor with vertical geometry comprises a base region (1) provided with a base contact (21), emitter and collector regions (2,3) arranged to extract minority carriers from the base region, and an excluding structure for counteracting entry of minority carriers into the base region via the base contact, wherein the base region has a bandgap of greater than 0.5 eV and a doping level greater than 1017 cm−3. As shown the base includes an excluding heterojunction (4) preventing entry of carriers from the base contact (21), but alternatively the base region could comprise a “high-low” doping homojunction. The construction shows improved resistance to thermal runaway even in multi-finger transistors. It is particularly useful for high power, high frequency transistors, e.g. base on gallium indium arsenide. The collector region preferably has a heterostructure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.