Origin of the Kink Effect in AlInN/GaN High Electron-Mobility Transistor

Kink effect is observed in Al0.83In0.17N/GaN high electron mobility transistor by measuring ID-VDS characteristics at a low sweep rate. It is inferred that the kink is induced due to the trapping/detrapping of charge carriers at deep levels present in the GaN buffer in the gate–drain access region. The detrapping of charge carriers from the deep levels is by the hot-electron-assisted mechanism. Two types of traps with activation energies, 0.29 eV (donor-like) and 0.57 eV (acceptor-like) were extracted by temperature-dependent transient drain current analysis. It is concluded that the deep-acceptor-like trap with a large emission time constant is responsible for the kink effect.