Kink effect and noise performance in isolated-gate InAs/AlSb High Electron Mobility Transistors

Abstract

Kink effect can spoil the otherwise excellent low-noise performance of InAs/AlSb HEMTs. It has its origin in the pile up of holes (generated by impact ionization) taking place mainly at the drain side of the buffer, which leads to a reduction of the gate-induced channel depletion and results in a drain current enhancement. Our results indicate that the generation of holes by impact ionization and their further recombination lead to fluctuations in the charge of the hole pile up, which provoke an important increase of the drain-current noise, even when the kink effect is hardly perceptible in the output characteristics.