Interaction of SiH3 radicals with deuterated (hydrogenated) amorphous silicon surfaces

Interactions of SiH3 radicals with surfaces of deuterated amorphous silicon (a-Si:D) and hydrogenated amorphous silicon (a-Si:H) films were studied using attenuated total reflection Fourier transform infrared spectroscopy and molecular-dynamics simulations, respectively. SiH3 radicals abstract surface silicon deuterides through an Eley–Rideal abstraction reaction. Surface deuteride abstraction occurs on the same time scale as SiH3 insertion into Si–Si bonds over the substrate temperature range of 60–300 °C. Some fraction of SiH3 adsorbing on the a-Si:D/a-Si:H films dissociates and releases H into the subsurface. These observations are consistent with the temperature independent reaction probability of SiH3 and the temperature dependent smoothening mechanism of a-Si:H thin films.