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

We have demonstrated a submicron heterojunction bipolar transistor (SHBT) with a unity current gain cutoff frequency (f_T) 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 f_T 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.