Paper: 1999 Equilibrium and nonequilibrium hydrogen coverages on vicinal Si(001) surfaces: Diffusion barriers and binding energies

Equilibrium and nonequilibrium hydrogen coverages on vicinal Si(001) surfaces: Diffusion barriers and bonding energies

Reviews and Highlights Quantum Science Molecular and Soft-matter Ultrafast Nano-optics and Nanophotonics Mineralogy and Geochemistry

M.B. Raschke, U. Hofer
Physical Review-Section B-Condensed Matter 59 (4), 2783-2789
DOI PDF

The surface kinetics of hydrogen adsorbed on VicinalĀ  Si(001) surfaces, misoriented towards the [110] direction, is investigated by means of optical second-harmonic generation. Following the selective saturation of the double-height DB steps by exposing the surface to a well-defined dose of molecular hydrogen, the transition from this nonequilibrium to an equilibrium hydrogen distribution is monitored in the temperature range between 580 and 730 K. A thermally activated diffusion process with a barrier of 1.7Ā±0.15 eV associated with the step depletion is observed. From measurements of the equilibrium hydrogen coverage the steps are found to be energetically favored with a H2-chemisorption energy difference of ~0.2 eV between step and terrace sites.