High performance double-doped InAlAs/InGaAs/InP heterojunction FET with potential for millimetre-wave power applications

Lattice matched InAlAs/InGaAs/InP heterojunction field-effect transistors (HJFETs), which have carrier supplying layers on and beneath the undoped InGaAs channel layer, have been successfully fabricated. A selective recess of the InGaAs channel edge at a mesa sidewall together with the use of a wide recess gate structure leads to a 5.7 V gate-drain breakdown voltage without kink effects. The fabricated HJFET with a 0.15 × 100 μm2 T-shaped gate exhibits a 700mA/mm maximum drain current, a voltage gain of 14, and a 345 GHz maximum frequency of oscillation.