Abstract :
Enhancement of silicon etching rate in XeF2 ambient is considered by a proposed model, which includes processes of
adsorption, activation, chemical reactions, relaxation, desorption, and sputtering. The enhancement of silicon etching rate is
explained by considering hydrocarbon species present in the vacuum chamber and assuming that activated sites (radicals) in the
polymer film enhance the etching rate. The composition of the adsorbed layer during silicon etching in XeF2 ambient is
calculated. It is found that activated polymer intensifies reaction of XeF2 molecules with Si atoms on the surface and causes the
variation of the etching rate. Using the obtained theoretical results the difference in kinetics of the etching rates of first and
subsequent runs is explained.
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