Thermodynamical Calculation and Experimental Confirmation of the Density of Hole Traps in SiO2 Films

Assuming the oxygen vacancy as a point defect, the density of oxygen vacancies in SiO2 films thermally grown on Si substrates is calculated thermodynamically, taking into account the strain incorporated into SiO2 films, and the calculated density of oxygen vacancies has been found to be in good agreement with the measured density of hole traps. The density of oxygen vacancies is thermodynamically predicted to decrease at lower oxidation temperature, and, consistently, it is experimentally shown that the density of hole traps is decreased from 2×1012 cm-2 to 1×1012 cm-2 by lowering the oxidation temperature from 1000°C to 900°C.