Method of manufacture of high speed, high power bipolar transistor
US4416708A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 15, 1982 |
| Grant date | Nov 22, 1983 |
| Priority date | — |
| Expiry date | Jan 15, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/965
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A high speed, high power bipolar transistor has a planar emitter structure having a central area and outer peripheral areas. The doping concentration in the central area is reduced as compared to that of the outer areas to reduce the injection efficiency at the central area of the emitter region. A low doped region of conductivity type opposite to that of the emitter surrounds the emitter area and can fully deplete to spread out the field to permit high voltage breakdown for the device. A novel process of manufacture is used wherein the doping concentration across the emitter area is controlled by diffusing the emitter through a pattern of elongated or rectangular or other cross-section masking islands which have closer spacing in the center of the emitter region to produce a lower average doping concentration in the center of the emitter than in the outer peripheral regions of the emitter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.