Modelling of the trap related parasitic effects in metamorphic HEMT on GaAs substrate

An investigation has been carried out on InAlAs/InGaAs metamorphic HEMTs on GaAs substrate dedicated to high performance amplifiers inserted in receiver as well as transmitter blocks of long distance and high bit rate optical links. This paper presents experimental results on parasitic effects, related to trapping/detrapping mechanisms (particularly gate lag, drain lag and kink effect). Trap signatures have been measured. The gate and drain lags impact is revealed to be different before or after the kink effect zone. These phenomena are detrimental both for digital and analogue applications of III-V field effect transistors. Models of these two effects, established according measurements and taking into account these impact changes, have been developed with ADS software in order to be inserted in the M-HEMT model.