Room-temperature adsorption of Si atoms on a hydrogen-terminated Si(001)-2 x 1 surface is studied using scanning tunneling microscopy/spectroscopy and first-principles total-energy calculations. We find that a Si atom adsorbs at the metastable bridge site of a Si dimer forming a SiH2 cluster at room temperature. Although Si adatom has a kinetic energy sufficient to overcome the activation energy at the moment of adsorption, the reaction path to the most stable off-centered inter-bridge site is narrow and the energy dissipation takes place before the transition. The ground-state adsorption is achieved by an annealing of the sample at 520 K.
ASJC Scopus subject areas
- Physics and Astronomy(all)