We report on the microwave performance and reliability evaluation of AlInAs
/GaInAs/InP HEMTs with InP as a top surface layer grown by MOCVD. It is fou
nd that HEMTs with thin InP surface layers provide high threshold voltage u
niformity, and less thermal and bias stress degradation compared to convent
ional AlInAs/GaInAs/InP HEMTs. A cutoff frequency f(T) of 53 GHz and maximu
m frequency f(max) of 210 GHz for a 0.4 mu M gate device is obtained. (C) 1
999 John Wiley & Sons, Inc.