Submicron AlInAs/InGaAs HBT with 160 GHz fT at 1 mA collector current

Abstract

We have demonstrated a submicron heterojunction bipolar transistor (SHBT) with a unity current gain cutoff frequency (ft) of 160 GHz at the very low current level of 1 mA. The AlInAs/InGaAs SHBT has a thin collector and uses stepper lithography with 0.1 μm registration accuracy to reduce the parasitic elements that typically limit the performance of small transistors. The same device has 100 GHz ft at 200 μA. The result substantially improves upon the cutoff frequency of submicron compound semiconductor devices. The technology is appropriate for high speed, low power, high-density circuits.