Physical mechanisms of performance instabilities such as gate-lag and kink phenomena in GaAs MESFETs

Slow current transients during turn-on (gate-lag) and abnormal increases in drain conductance (kink) in GaAs MESFETs are studied by two-dimensional analysis including surface states and impact ionization of carriers. Particularly, it is discussed how the gate-lag is influenced by impact ionization of carriers and how the surface-related kink depends on the structural parameters such as gate length and distance between source and gate.