Atomic Hydrogen: A Reagent for the Extraction of Chemical Species from Silicon Surfaces.

摘要

The surface chemistry of adsorbed halogen atoms on Si(100) has been studied using several surface science methods. It has been found that Cl atoms bond to dangling bonds on symmetric Si2 dimer sites, and that the Si-Cl bond angle is tilted from the normal in the vertical plane containing the Si2 dimer bond. The covalently-bonded halogens Cl, Br, and I have been studied on Si(100) using atomic hydrogen bombardment at low substrate temperatures (300 - 630 K). In all cases, facile elimination of the hydrogen halide occurs, and the coverage of halogen may be driven to zero by moderate exposure to atomic hydrogen. The halogen extraction process is almost non-activated, suggesting that the chemical reaction to produce hydrogen halide species is driven by the potential energy carried by the atomic hydrogen species. This is an example of an Eley-Rideal reaction process and provides a potentially useful new approach for controlling atomic layer chemistry on semiconductors. Silicon, Extraction, Halogens, Atomic layer epitaxy, Eley-Rideal reactive, Atomic hydrogen.