Characterization and modeling of single defects in GaN/AlGaN fin-MIS-HEMTs

Charge trapping in gallium-nitride (GaN) metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMTs) is a serious reliability challenge but is still poorly understood. A promising opportunity to investigate physical defect properties has become available through nanoscale GaN fin-MIS-HEMTs which are small enough to be sensitive to the impact of individual defects. In this work, we extract the properties of four pre-existing single defects, which are identified by their correlated random telegraph noise (RTN) signals and step heights. We use a two-state non-radiative multi-phonon (NMP) model to extract their vertical positions, their trap levels and their apparent activation energies. We show that they are in close proximity to each other within the barrier layer and also share a similar trap-level despite their different capture and emission times. Furthermore, TCAD simulations are used to estimate the influence of the vertical and horizontal positions of single-traps which are in reasonable agreement with the experimental data.