Pseudomorphic InP/InGaAs Heterojunction Bipolar Transistors (PHBTs) Experimentally Demonstrating fT = 765 GHz at 25°C Increasing to fT = 845 GHz at -55°C

Pseudomorphic InP HBTs (PHBTs) with a vertically scaled design implementing a 12.5 nm base and 55 nm collector exhibit record current gain cutoff frequency performance of f
_T
=765 GHz when measured at 25°C. When cooled to -55°C, f
_T
improves more than 10% to f
_T
=845 GHz due to enhanced electron transport and reduced parasitic charging delays as determined by small signal equivalent circuit parameter extraction. Peak performance current density J
_c
=18.7 mA/μm
²
and BV
_CEO
=1.65 V