Patent · US Expired

Bipolar transistor having external base region

US5124270A · kind A · utility

29Cited by
5References
3Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 17, 1990
Grant dateJun 23, 1992
Priority date
Expiry dateSep 17, 2010

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S148/072

Abstract

A bipolar transistor is provided with an external base region. The bipolar transistor comprises a first semiconductor layer of a first conductivity type, the first semiconductor layer serving as a collector region, a second semiconductor layer of a second conductivity type, which is formed on the first semiconductor layer and includes a base region and an external base region located around the base region, a third semiconductor layer of the first conductivity type, which is formed on the second semiconductor layer and serves as an emitter region, a metal layer formed on the third semiconductor layer and serving as an emitter electrode, the metal layer including a first metal layer portion which is substantially as wide as the base region located in an intrinsic transistor region, and a second metal layer portion which is formed on the first metal layer portion and is wider than the first metal portion, a base electrode located on the external base region of the second semiconductor layer, and a collector electrode connected to the first semiconductor layer.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.