Characterization of low temperature transport properties in InP/InGaAs double heterojunction bipolar transistors

Low temperature transport properties of InP/InGaAs double heterojunction bipolar transistors (DHBTs) have been carefully investigated. The mechanisms for the devices operating in different temperature range have been clearly identified. The base current in the temperature range of 240 to 300 K is dominated by electron-hole band-to-band recombination and trap related recombination. In the temperature range of 77 K to 240 K, trap related recombination mechanism plays a important role in determining the base current. For temperature lower than 77 K, both collector and base currents are found to be limited by the electron tunneling through the barrier formed by conduction-band discontinuity at E-B junction