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 Al
₂
O
₃
, HfO
₂
, LaAlO
₃
, GdScO
₃
, and HfO
₂
/Ga
₂
O
₃
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. Al
₂
O
₃
and HfO
₂
/Ga
₂
O
₃
bilayer dielectrics are identified with the lowest interface recombination velocity (S=7×10
⁴
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.