OXYGEN STICKING COEFFICIENTS ON CLEAN (111) SILICON SURFACES

Measurements obtained by activation analysis of the oxygen 18 adsorption on (111) silicon have been used to obtain the kinetic curve for chemisorption from 0.03 to 0.97 monolayers. A graphical differentiation of this kinetic curve gives a plot of the oxygen sticking coefficients versus coverage. Two distinct regions of oxidation at room temperature are observed: an initial rapid growth region below 0.7 monolayers, followed by a much slower adsorption above 0.7 monolayers as normal oxide film formation commences. The results give a value for the maximum sticking coefficient at the extrapolated zero coverage of S = 0.15 and decreases to S = 0.015 at a coverage of 0.7 monolayers. © 1969.