Heterojunction bipolar transistor with base electrode having Schottky barrier contact to the emitter
US5331186A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 5, 1992 |
| Grant date | Jul 19, 1994 |
| Priority date | — |
| Expiry date | Mar 5, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/64
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A high-cut-off frequency, high-speed HBT is obtained by suppressing the diffusion of impurities to the utmost by lowering a heat treatment temperature in the step subsequent to the formation of a high concentration base layer. A base electrode for a base layer is made of a metal or an intermetallic compound which extends the emitter layer to reach at least a part of the base layer. The metal or intermetallic compound forms Schottky barrier with an emitter layer having a wide forbidden width ,and ohmic contacts with the base layer with a narrow forbidden band. The barrier potential of the Schottky junction formed between the intermetallic compound or metal and the emitter layer is higher than the diffusion potential of a pn junction between the base layer and the emitter layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.