Ultra high-speed InP-InGaAs SHBTs with fmax of 478 GHz

InP-based single heterojunction bipolar transistors (SHBTs) for high-speed circuit applications were developed. Typical common emitter DC current gain (/spl beta/) and BV/sub CEO/ were about 17 and 10 V, respectively. Maximum extrapolated f
_max
of 478 GHz with f
_T
of 154 GHz was achieved for 0.5 × 10 μm
²
emitter size devices at 300 kA/cm
²
collector current density and 1.5 V collector bias. This is the highest f
_max
ever reported for any nontransferred substrate HBTs, as far as the authors know. This paper highlights the optimized conventional process, and the authors have great hopes for the process that offers inherent advantages for the direct implementation to high-speed electronic circuit fabrication.