Comparative study on temperature-dependent characteristics of InP/InGaAs single- and double-heterojunction bipolar transistors

Interesting temperature-dependent characteristics of InP/InGaAs-based single-heterojunction bipolar transistor (SHBT) and double-heterojunction bipolar transistor (DHBT) devices are compared and studied. Experimentally, both studied devices show wider collector current (I-C) operation regions, with over 11 decades in magnitude of collector current (I-C = 10(-12) to 10(-1) A). However, the studied DHBT exhibits improved breakdown characteristics [common-emitter breakdown voltage (BVCEO) = 8.05 V and common-base breakdown voltage (BVCBO) = 11.3 V] and low output conductance at high temperature. Moreover, the undesired current-blocking effect, switching, hysteresis phenomenon usually found in an InP/InGaAs conventional DHBT are not observed in the DHBT device. As compared with the studied SHBT, the studied DHBT shows a lower multiplication factor and weaker temperature dependence. Therefore, it is known that, based on experimental results, the studied DHBT device provides the promise for low-voltage and low-power circuit applications. (C) 2008 American Vacuum Society.