DYNAMICS OF THE KINK EFFECT IN INALAS INGAAS HEMTS/

We have carried out pulsed measurements of the kink effect in InAlAs/I nGaAs HEMT's on InP with nanosecond resolution. Our measurements show that the kink's characteristic time constant is strongly dependent on V-DS, i.e., it drops by more than three decades, from 100 mu s down to 50 ns, between low and high values of V-DS. This suggests that the ki nk should not be operational for frequencies in the microwave and mill imeter wave regimes. We also find that the kink turn-on dynamics corre late with impact ionization. In particular, the inverse of the kink's characteristic time constant follows a classical impact ionization beh avior.