Adsorption kinetics of H on Si(111)7×7 by means of surface differential reflectivity

Abstract

The kinetics of hydrogen adsorption on Si͑111͒7ϫ7 have been studied by means of real-time surface differential reflectivity. Experiments have been performed for a large exposure range and for temperature ranging from 170-370 K. Two different adsorption channels could be determined from the analysis of the spectra. The kinetics equations of the two elementary processes have been written, and their respective activation energies have been determined: a very low barrier for the H binding on the adatom dangling bonds and a barrier of about 20 meV for the H breaking of the adatom back bond. The kinetics of both processes can be understood by taking into account a large energy barrier that inhibits the adatom-back-bond breaking by H as long as the dangling bond of the adatom is not yet bound to H.

Large differences in the optical properties of a single layer of Si on Ag(110) compared to silicene

“…In contrast, the reflectance of opaque substrates can be measured and, combined with differential methods, can be sensitive to small amounts of silicon. Surface differential reflectance spectroscopy (SDRS), which provides the relative change in reflectance of the sample due to the presence of additional atoms or molecules on the surface, has been shown to be an efficient technique to study adsorption phenomena [18,19], growth of very thin films on such substrates [20][21][22], and also to follow their kinetics [23,24].…”

Reflectance-anisotropy spectroscopy and surface differential reflectance spectra at the Si(100) surface: Combined experimental and theoretical study

“…So far, this combined approach in theory and experiments has been employed in a limited number of cases. 4,[11][12][13][14][15][16][17] In the present work, we consider the case of Si͑100͒, clean and covered with hydrogen. Set apart as a paradigmatic surface because of its relatively simple reconstruction, Si͑100͒ is a substrate of major importance for development of microelectronic devices, and the control of adsorption of molecules on this surface by means of versatile and easy-to-use optical techniques is promising for applications.…”

Optical investigation of benzene adsorption on vicinal single-domainSi(001)−(2×1)surfaces

“…15,16 Indeed, it has been shown that surface sensitive optical spectroscopies can be a useful tool to determine the kinetics of gas adsorption. 19,20 Here, we use RAS and SDRS, combined with scanning tunneling microscopy ͑STM͒, to investigate the adsorption of benzene on the silicon ͑001͒-2 ϫ 1 vicinal surface.…”