Formation of nanocrystalline Si by Au-catalyzed CH_3SiH_3 pulse jet CVD

摘要

Au-catalyzed growth of nanocrystalline Si by pulse jet chemical vapor deposition has been investigated. Au thin film was first deposited on thermally oxidized Si(100), then CH_3SiH_3 pulse jets were irradiated onto the Au/SiO_2/Si(100) surface. The irradiation of the CH_3SiH_3 jets at 1150 ℃ resulted in circular patterns with a diameter of ～40 μm on the sample surfaces. In the center of the circular patterns, agglomerations of Au were observed. It was found that the oxide layer was etched and that nanocrystalline Si with diameters ～500 nm was formed in the circular patterns. These results indicate that the nanocrystalline Si was grown by the VLS process in which Si atoms were supplied from the oxide layer, Si substrate, and CH_3SiH_3 molecules.