The interface properties of MIS structures on anodically oxidized GaSb

Extensive capacitance - voltage (C - V) and conductance - voltage (G - V) measurements have been performed on MIS devices on p-type GaSb at 77 K using an anodically grown oxide as the insulating layer. The C - V characteristics have been measured from 250 Hz to 800 kHz. The high-frequency C - V data and the G - V analysis are in good agreement and show that there is a high density of surface states which limits the movement of the surface potential to a region of approximately of the bandgap. Hence neither accumulation nor inversion can be obtained.