A numerical study of the temperature dependence of the unity gain frequency of silicon bipolar transistors

Abstract

The dependence of the unity gain frequency f/sub T/ of a silicon double-diffused bipolar transistor on temperature and collector current density at 77-300 K is discussed. The f/sub T/ characteristics are generated by the low-temperature bipolar transistor simulator BILOW. Physical explanations of the f/sub T/ plots are given on the basis of simulated distributions of various internal parameters of the bipolar transistor. The temperature dependence of f/sub T/ is found to be strongly influenced by the charge of the minority carriers trapped in the base on the compensated impurity atoms. The electric-field distribution within the base is changed as a result of the additional charge.<>