Abrupt Delta-Doped InP/GaInAs/InP DHBTs With 0.45-$\mu\hbox{m}$ -Wide T-Shaped Emitter Contacts

An abrupt pulse-doped InP/GaInAs/InP double heterojunction bipolar transistor having a 0.45- $\mu\hbox{m}$-wide T-shaped emitter metal is reported. These two promising technologies for sub-100-nm emitters were previously demonstrated only for 1- $\mu\hbox{m}$ emitters. The device exhibited typical dc and microwave performance to 0.5- $\mu\hbox{m}$ emitter devices.