Extending the Bandwidth and Functionality of High Performance InP HBT Technologies

Fig. 1. Cross-section of self-aligned base-emitter junction from Teledyne 500nm HBT process [6] InP-based transistor technologies, both high electron mobility transistors (HEMTs) and double heterojunction bipolar transistors (DHBTs), have demonstrated the highest reported transistor RF figures-of-merit. Both device technologies have been reported with current gain cutoff frequencies (ft) in excess of 600GHz [1,2], and power gain cutoff frequencies (fmax) in excess of 1THz [3,4]. These performance records are achieved because of the inherent advantages of the InP/InGaAs material system (high electron mobilities/velocities, low attainable Ohmic contact resistivities and large heterojunction offsets), and through aggressive transistor scaling. With their wideband gap InP collector InP DHBTs offer a higher breakdown voltage than InGaAs-channel HEMTs at the same ft. Their high-speed and high-voltage handling make HBTs suitable for a wide breadth of applications including: sub-mm-wave and THz frequency integrated circuits, >100Gbit/sec optical and wireless communication circuits, microwave operational amplifiers, and high resolution microwave frequency analog-to-digital and digital-to-analog converters. In this paper, we review HBT and IC results from Teledyne Scientific Company’s InP HBT technology. A scalable device architecture has been developed and successive generations of the technology have been demonstrated (500nm to 130nm). Increased functionality of the technology is being pursued with the development of a BiFET (HBT+HEMT) InP technology and through heterogeneous integration with Silicon CMOS.