Control of fixed charge at Si–SiO2 interface by oxidation-reduction treatments

Abstract

Silicon dioxide films thermally grown on silicon have been reduced by exposure to low‐oxygen‐partial‐pressure atmospheres in mixtures of CO and CO2 at 910 °C. After several hours an equilibrium oxide charge was observed at each oxygen partial pressure. Capacitance voltage measurements on the reduced samples have shown a large increase in the oxide's positive charge. The increase in charge resulting from reduction can be eliminated by exposing the samples to oxygen for 1 h. These findings suggest a relationship between the oxide charge and oxygen vacancies.