Comparative Study of High- $k/{\rm GaSb}$ Interfaces for Use in Antimonide Based MOSFETs

Electrical interface quality of various high- k dielectrics on GaSb, including Al₂O₃, HfO₂, LaAlO₃, GdScO₃, and HfO₂/Ga₂O₃ bilayer has been studied and compared with reference low (AlGaSb) and high D_it (native oxide) interfaces using photoluminescence intensity measurements for the first time. Al₂O₃ and HfO₂/Ga₂O₃ bilayer dielectrics are identified with the lowest interface recombination velocity (S=7×10⁴ cm/s) and consequently D_it integrated across essentially the entire bandgap. However, S for even the best identified high- k dielectrics is elevated by 140× over the low D_it AlGaSb reference indicating the need of further improvements for envisioned use in Sb based MOSFETs.