INTERFACE STATES GENERATED BY HEAT-TREATMENT IN AU/INGAP SCHOTTKY DIODES

This work is a study of the formation of interface traps in Au/n-In0.5Ga0.5P contacts. The effects of heat treatment near the ohmic alloying temperature on the characteristics of the Schottky diodes are studied using current-voltage (I-V), capacitance-voltage (C-V), and deep level transient spectroscopy measurements. New interface states that are distributed around 0.73 eV below the conduction band minimum were generated by heat treatment above 350-degrees-C before metallization. In a sample that was heat treated at 400-degrees-C for 30 min, the maximum density of generated interface states was estimated to be approximately 2 X 10(11) cm-2 eV-1. The origin of these interface states is attributed to the transformation of a phosphorus vacancy that is generated by the vaporization of phosphorus from the surface of In0.5Ga0.5P.