THE INTERFACE PROPERTIES OF MIS STRUCTURES ON ANODICALLY OXIDIZED GASB

Extensive capacitance-voltage (C-V) and conductance-voltage (G-V) meas urements have been performed on MIS devices on p-type GaSb at 77 K usi ng an anodically grown oxide as the insulating layer. The C-V characte ristics 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 ther e is a high density of surface states (similar to 10(13) cm(-2) eV(-1) ) which limits the movement of the surface potential to a region of ap proximately 1/4 of the bandgap. Hence neither accumulation nor inversi on can be obtained.