Vertical scaling of 0.25-μm emitter InP/InGaAs single heterojunction bipolar transistors with fT of 452 GHz

Vertical scaling of the epitaxial structure has allowed submicron InP/InGaAs-based single heterojunction bipolar transistors (SHBTs) to achieve record high-frequency performance. The 0.25×16 μm
²
transistors, featuring a 25-nm base and a 100-nm collector, display current gain cut-off frequencies f
_T
of 452 GHz. The devices operate at current densities above 1000 kA/cm
²
and have BV/sub CEO/ breakdowns of 2.1 V. A detailed analysis of device radio frequency (RF) parameters, and delay components with respect to scaling of the collector thickness is presented.