Low Temperature Fluorinated Silicon Films Synthesis

摘要

The plasma-enhanced chemical vapor deposition (PECVD) at low temperature of preparation of fluorinated and hydrogenised nanocrystalline silicon films was studied by using Fourier-transform infrared spectroscopy and atomic-force microscopy. There are numerous molecular configurations are incorporated into the silicon lattice. The silane molecule dissociates and SiH or SiH_2 fragments are chemisorbed on substrate. By using the additional SiF_4 there is etching on the surface, and SiF and SiF_2 bonding are appeared on the film's surface. It is assumed that the hydrogen is incorporated in the silicon lattice by low temperature (＞100℃) and reacts with oxygen to produce the H_4SiO_4 assembly. By increasing in temperature of deposition the molecular creation and dissociation rates increase. By the same way the HF acid interacts with the SiF_4 and produces H_2SiF_6. In addition, SiF_4 react with H_2O and are appeared H_2SiF_6 in the silicon lattice, too.