Demonstration of npn InAs bipolar transistors with inverted base doping

We demonstrate np/sup +/n InAs bipolar transistors that operate under room temperature and cryogenic conditions. InAs transistors on an InP substrate were characterized as a function of temperature and exhibited good room temperature and low temperature common-emitter characteristics. Although the base doping density exceeded the emitter doping density by a factor of 20, current gains of 30 were achieved at room temperature. Junction leakage currents and contact resistance were identified as problems to address.