The adsorption and thermal decomposition of acetylene on Si(100) and vicinal Si(100)9°

First-principles study of the adsorption ofC2H2andCho1, Kleinman2, Chan3 et al. 2001Phys. Rev. B51250View full textAdd to dashboardCite

“…For both adsorbed molecules the dimerized model is found to be more stable than the dimercleaved model as well as the tetra-model, showing that the carbon atoms of adsorbed C 2 H 2 and C 2 H 4 form sp 2 and sp 3 bonding, respectively. This result supports the majority of the experimental data [3][4][5][6][7][8] except that of a recent photoelctron imaging experiment, 7 where the tetra-model was proposed for adsorbed C 2 H 2 . Moreover, C 2 H 4 molecules favor adsorption on alternate Si dimers rather than on neighboring dimers along a dimer row, because of the repulsive hydrogenhydrogen interaction between adsorbed C 2 H 4 .…”

“…1,2 Despite a wealth of experimental [3][4][5][6][7][8] and theoretical 9-11 studies on both adsorbed molecules, several basic issues on the adsorption site, bonding characteristics, and saturation coverage are still controversial.…”

“…For the adsorption site of C 2 H 2 and C 2 H 4 on Si͑100͒, various experimental studies using high-resolution electronenergy-loss spectroscopy, 3 scanning tunneling microscopy ͑STM͒, 4 near-edge x-ray-absorption fine structure ͑NEXAFS͒, 5 and photoelectron diffraction ͑PhD͒ 6 found that both molecules are adsorbed on the top of Si dimers, where the C-C bond is parallel to the Si dimer bond, by forming two bonds between C and Si atoms ͓see Fig. 1͑a͔͒.…”

Optical and mechanical properties of plasma-beam-deposited amorphous hydrogenated carbon

“…One reason for this could be the fact that acetylene molecules easily chemisorb nondissociatively on a Si͓100͔ surface at room temperature. 11 Another reason could be that interaction of low-energy argon ions is important before deposition starts. When the plasma is switched off before the acetylene addition is ceased, a film with a rather rough surface is the result.…”

Theoretical modelling of surface phonons

“…Thus precise characterisation of the C-C bond is very important in determining the adsorption site of the C 2 H 2 molecule. Unfortunately, as can be noted from the table, there is a large spread in C-C vibrational modes from HREELS measurements from different groups [23][24][25]. Although total energy calculations [26] suggest that di-σ -bond structure is the most stable, some of the metastable configurations, such as the tetra-σ model, are also possible.…”