Effects of implant spacer on InP-based self-aligned pseudomorphic SIGFETs

An InP-based normally-off superlattice-insulated-gate field-effect transist or (SIGFET) with a T-shaped gate structure has been developed using an angl ed self-aligned implant process. The spacing to the nf source/drain regions created with this new process increases:the breakdown voltage and lowers t he gate capacitance. It also reduces the short channel effect while a high g(m) value is maintained. A cutoff frequency f(T) of 45 GHz was obtained fo r the SIGFET with 0.56 mu m gate length.