AlInAs/GaInAs HBT IC technology

Integrated circuits (ICs) fabricated with AlGaAs/GaInAs heterojunction bipolar transistors (HBTs) lattice matched to InP substrates are described. The transistors used in this work consisted of an abrupt emitter-base junction design. A cutoff frequency and a maximum frequency of oscillation of 90 and 70 GHz, respectively, have been achieved with a 2*5- mu m/sup 2/ emitter size HBT. Current-mode logic (CML) was used to demonstrate ring oscillators, flip-flop divider circuits, and dual-modulus prescalers. The ring oscillator demonstrated a 15.8-ps gate delay, the CML flip-flop divider circuits demonstrated 24.8-GHz toggle rates, and the 4/5 and 8/9 dual-modulus prescalers consisting of 106 and 124 transistors, respectively, operated at clock rates of up to 9 GHz.<
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