Abstract
Hydrogen accumulation on the Si(111) 7 × 7 surface due to water adsorption at room temperature was investigated by the flash desorption technique. The water pressure varied from 10 −11 to 10 −7 Torr. The sticking coefficient S turns out to decrease from S = 0.08 at a water pressure of 10 −9 Torr to 0.009 at 10 −7 Torr, i.e. S does depend not only on exposure but on the exposure time itself. We suppose that the chemisorbed water might form a 2D phase of the Si, OH, H and O species. Probably, the phase starts at steps (fast adsorption stage). The number of Si atoms in the new phase layer should not necessarily be equal to the effective Si surface density in the clean (111) 7 × 7 layer. Surface diffusion of Si atoms to or from the growing chemisorbed phase (slow adsorption stage) determines the dependence of the sticking coefficient not only on exposure but also on time itself.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.