Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) has been applied to characterize amorphous silicon monohydride films before and after reaction with deuterium atoms. The hydride films were grown by chemical vapor deposition on oxide-covered silicon substrates, and the data suggest that the film is terminated by a homogeneous monolayer of primarily dimerized silicon monohydride. Exposure of this film to atomic deuterium causes the replacement of silicon hydride with adsorbed deuterium. Only the monodeuteride is formed by reaction at 200 °C. Reaction at −110 °C produces mono-, di-, and trideuteride, demonstrating that the isolation of insertion products is temperature-dependent.

We report structural and kinetic studies of the reactions of hydride species in Si thin films with atomic deuterium (Dat). Infrared (IR) spectroscopy is used to obtain Si−H bonding information, and direct recoiling methods are used to measure reaction rates. Two kinds of films are prepared by filament-assisted growth from Si2H6 and are characterized by IR spectroscopy. A film containing only monohydride hydrogen is grown at 200 °C, and a polymer containing tri-, di-, and monohydride is grown at −110 °C. Rates of H abstraction by Dat, and of Dat insertion into Si−Si bonds, are reported. The abstraction rate of H by Dat in both films is similar to the abstraction rate on H-terminated crystal Si surfaces. The insertion rate into Si−Si bonds in both films is about one-tenth the rate of abstraction. A qualitative study of the etching reaction of Dat with the polymeric film is reported, and a strong temperature dependence is observed.