Some aspects of inverse bipolar transistor improvement through recombination reduction

This paper describes the effect of recombination in the external base and epitaxial regions on the inverse current gain and related parameters of the n+pnn+ bipolar transistor. It is shown that the inverse current gain increases with the decrease in recombination in the external base region by use of the doublebase process. Improvement of the inverse gain is also shown with a decrease in epitaxial-layer thickness until it reaches a point of diminishing return at about one micrometre width between the space-charge regions. Breakdown phenomena related to the external base depth and the epitaxial layer thickness are also discussed.