(Invited, Digital Presentation) Langmuir-Type Formulation for Atomic-Order Surface Reactions of Reactant Gases on Si (100) and Ge (100) Surfaces

Atomic-order surface reaction processes of reactant gases on the Si (100) and Ge (100) surfaces are reviewed. The site density on the (100) surface where the reactant molecules are adsorbed and react is estimated from the maximum self-limited adsorption/reaction amount of reactant gas on the (100) surface. The atomic-order amounts of reactant gases under self-limiting adsorption/reaction conditions are described using a modified Langmuir-type mechanism as a function of reactant gas partial pressure and exposure time at a specified temperature. For the hydrogen-terminated surface, it is proposed that the reactant molecules are physically adsorbed on the hydrogen-terminated sites and react with the hydrogen terminated on the surface. Fairly good agreement is obtained between all experimental data and the modified Langmuir-type mechanism for the self-limited adsorption/ reaction.