Role of the Chemisorption of the Oxidant in the Oxidation of Si and SiC

Abstract

It is shown by the elementary calculations that the steady-state coverage of the oxidant Θs chemisorbed on the oxide surface in the oxidation of Si and SiC depends logarithmically on the partial pressure of the oxidant Pox in the ambient environment. Using this result and the equation we derived previously to describe the oxide thickness xo as a function of the oxidation time and temperature, xo is calculated and compared with the experiments on Si(100), 4H-SiC\((000\bar{1})\) C-face, and 4H-SiC\((11\bar{2}0)\) a-face to show that the pressure dependence of the oxidation rate in the thermal oxidation of Si and SiC results from that of Θs provided that Pox is sufficiently high to maintain the steady-state condition of the oxidant chemisorbed on the oxide surface.