Transistor of increased power - having emitter surrounded by enhanced conductivity region spaced from contact metallization

摘要

A transistor is made by forming a base region of one conductivity type on a collector of opposite type, forming in the base an enhanced conductivity region of given area and depth having a higher dopant concentration than the base and of the one conductivity type, diffusing into the enhanced conductivity region an emitter region of the opposite conductivity type, having a smaller area but extending beneath the enhanced conductivity region, and forming ohmic contact metalligation over the emitter and base region, spaced from the enhanced conductivity region. Transistor has increased power output and/or reduced size.