ABSTRACT
Abstract. Deep-level traps affect significantly the performance of modulation-doped InAlAs/InGaAs metamorphic HEMTs (MHEMTs) on GaAs wafers. The dynamic behaviour of the traps related to the kink in short-gate MHEMTs has to be more comprehensively understood for better fabrication and development of the devices for over-100-GHz millimeter-wave applications. In this paper, we analyze the dynamic trap effects related to the soft kink at lower drain current in the short-gate MHEMTs through rigorous 2D hydrodynamic transport simulations. The simulations give a good agreement with the measured DC characteristics of a fabricated MHEMT, and good insight of the dynamic behaviour of the deep-level traps related to the soft kink in short-gate MHEMTs. In addition, we show that the gate sinking, the hole-trapped donor-type buffer, and the impact ionization enhances the hole pile-up at the source side of the gate, which could cause the soft kink at lower drain current in short-gate MHEMTs.
