Impact of the pulse-amplifier slew-rate on the pulsed-IV measurement of GaN HEMTs

Abstract

The influence of the non-ideal response of the pulse-amplifier on the trap and self-heating dynamics, and hence, on the drain-current transient in a GaN HEMT is studied with new trap and self-heating models. It is shown that the study of the trap and self-heating dynamics requires a proper correction technique that accounts for the change in trap-potential, trap time-constant and thermal response due to the non-ideal response of the pulse-amplifier. Several post-measurement data correction techniques are discussed and shown to be incapable of predicting the true drain-current transient. A pre-measurement terminal correction technique using a new version of the pulse measurement system is used to solve the problem.