CHEMICAL-COMPOSITION OF AL2O3 INP METAL-INSULATOR-SEMICONDUCTOR INTERFACES IMPROVED BY PLASMA AND ULTRAVIOLET OXIDATION/

Plasma and ultraviolet (UV) oxidation are used to obtain insulating fi lms for the fabrication of an InP metal-insulator-semiconductor diode. A thin Al film is deposited onto a UV-oxidized n-type InP wafer and t he Al film is oxidized with the use of a microwave-excited O-2+N-2 mix ture plasma. The depth profile of the composition of the oxidized film is measured by XPS with the aid of Ar ion sputtering. An annealing pr ocedure in N-2-atmosphere followed by H-2-atmosphere annealing was app lied to MIS diodes. Resultant InP MIS diodes show excellent C-V charac teristics with very small hysteresis. C-V measurements at 1 MHz yield a minimum interface trap density of 6 x 10(10) cm(-2) eV(-1).