High-resolution photoemission study of acetylene adsorption and reaction with the Si(100)-2{times}1 surface

Journal Article · Fri Oct 01 04:00:00 EDT 1999 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.60.11586· OSTI ID:692556

Xu, S H; Yang, Y; Keeffe, M; Lapeyre, G J ^[1]; Rotenberg, E ^[2]

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1. Physics Department, Montana State University, Bozeman, Montana 59717 (United States)
2. Advanced Light Source, LBNL, Berkeley, California 94720 (United States)

The adsorption and reaction of acetylene with the Si(100)-2{times}1 surface has been studied using high-resolution photoemission by monitoring the Si&hthinsp;2p, C&hthinsp;1s, and valence-band (VB) spectra as a function of both acetylene coverage and post-adsorption annealing temperature. After the clean Si(100) surface is exposed to 0.5 monolayer (ML) acetylene, the surface state in the VB is absent. Meanwhile, the curve-fitting results show that there is only one interface component in the Si&hthinsp;2p core level. These results indicate that the asymmetric Si dimers may become symmetric dimers after acetylene adsorption, which can be explained well by the tetra-{sigma} model determined from our previous photoelectron holographic results. Significant changes in the electronic structure (Si&hthinsp;2p, C&hthinsp;1s, and VB) are found after subsequent annealing of the saturation overlayer. Annealing at lower temperature can induce some acetylene molecule desorption while most of the molecules decompose into C{sub 2}H{sub x} (x=1,0) and H species. After annealing above 660&hthinsp;{degree}C, both of the reacted components of the Si&hthinsp;2p and C&hthinsp;1s lines show that the SiC species form clusterlike features. At the same time, the VB and Si&hthinsp;2p spectra indicate a restoration of a Si(100)-2{times}1 structure, and the asymmetric Si dimers reappear on the surface. {copyright} {ital 1999} {ital The American Physical Society}

• OSTI ID: 692556
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 16 Vol. 60; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ACETYLENE
ADSORPTION
ANNEALING
CHEMICAL REACTIONS
DECOMPOSITION
ELECTRONIC STRUCTURE
ORGANIC COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHOTOEMISSION
SILICON
SURFACES