A model of formation of fixed charge in thermal silicon dioxide

A quantitative model of formation of fixed charge (Qf) in silicon dioxide during thermal oxidation of silicon is developed. The value of Qf is governed by the number of interstitial silicon atoms in the vicinity of the Si-SiO2 interface; these atoms are formed as a result of the processes of their generation and recombination at the interface and also due to their diffusion to the depth of dioxide. The model makes it possible to describe a decrease in the fixed charge as the oxidation temperature is increased and in the case of annealing in neutral media for silicon dioxide on silicon with orientations (100) and (111) in a wide range of temperatures.