Influence of Si surface structure on reaction mechanism: Atomic hydrogen+adsorbed Br

The reaction of atomic hydrogen with adsorbed Br is compared on Si(100) and Si(111) surfaces from 50°C to 300°C. On both surfaces, Br removal rate is first order in atomic hydrogen flux, first-order in Br coverage, and exhibits a near zero activation energy. On Si(111), this rate also depends on surface hydrogen coverage, indicating that different mechanisms occur on these surfaces. © 1993 American Institute of Physics.