100+ GHz transistor electronics; present and projected capabililties

Design principle and the present status of high-frequency transistors and integrated circuits are reviewed. Given presently-demonstrated process and material parameters, bipolar transistors having ∼3 THz power-gain cutoff frequencies are feasible. Demonstration of field-effect transistors having similar bandwidth requires development of high-capacitance-density gate dielectrics of adequately low leakage current, and high-K oxide gate barriers may therefore be necessary. Transistors of such bandwidths would enable e.g. ∼1.5 THz radio transmitters and receivers; classical electron device and circuit techniques are feasible over most of the sub-millimeter-wave (0.3–3 THz) spectrum.