Two new generalized equations for minority-carrier transport in bipolar transistors with heavily doped base and non-uniform band structure

1 June 1992

journal article
Published by IOP Publishing in Semiconductor Science and Technology

Vol. 7 (6) , 799-803
https://doi.org/10.1088/0268-1242/7/6/011

Abstract

Two new, simple, general and rigorous closed-form integral solutions to the base current density and to the base transit time for electron transport in NPN bipolar transistors with heavily doped base and non-uniform band structure are presented. The expressions include the effects of non-uniform band structure, the influence of Fermi-Dirac statistics, the position-dependent mobility and the velocity saturation effect at the base-collector depletion-layer edge on the base side. An application of this new simplified base current density of equation to Early voltage in a narrow-base bipolar transistor is illustrated. A simple example for the effects of the minority-carrier density and of the base built-in field on the minority-carrier base transit time is also qualitatively discussed.

Keywords

This publication has 15 references indexed in Scilit:

The asymptotes of the base current in bipolar devices
IEEE Transactions on Electron Devices, 1988
A consistent model for carrier transport in heavily doped semiconductor devices
Semiconductor Science and Technology, 1988
Current gain of narrow-base transistors
Solid-State Electronics, 1986
The physics and modeling of heavily doped emitters
IEEE Transactions on Electron Devices, 1984
Heavily doped transparent-emitter regions in junction solar cells, diodes, and transistors
IEEE Transactions on Electron Devices, 1979
Heavily doped semiconductors and devices
Advances in Physics, 1978
The emitter efficiency of bipolar transistors: Theory and experiments
Solid-State Electronics, 1977
The emitter efficiency of silicon transistors
Solid-State Electronics, 1977
Impurity concentration dependent density of states and resulting fermi level for silicon
Solid-State Electronics, 1971
The Dependence of Transistor Parameters on the Distribution of Base Layer Resistivity
Proceedings of the IRE, 1956