Lateral scaling of 0.25 (mu)m InP/InGaAs SHBTs with InAs emitter cap

InP/InGaAs single heterojunction bipolar transistors (SHBTs) have been fabricated using a highly doped InAs emitter cap for a 50% reduction in emitter resistance to allow aggressive lateral scaling to increase f/sub MAX/. Type I InP SHBTs have been fabricated with 0.25 (mu)m emitter widths and achieve f/sub MAX/ values as high as 478 GHz on a laterally scaled L/sub E/=1 (mu)m device, and maintain breakdown voltages greater than 4 V.