Ab initio Molecular Orbital Study of Water Absorption and Hydrolysis of Chemical Vapor Deposited SiOF Films II

Publisher Website
Google Scholar
Abstract
In part 1, we reported the mechanism of water absorption and hydrolysis of SiOF films theoretically using the ab initio molecular orbital (MO) method with small SiF n (OH)4- n (n=0–3) tetrahedral model clusters. It was revealed that the multiple F-substituted Si atoms had a higher reactivity against both OH- and H2O than Si atoms with one or no Si–F bonding. Also, defect sites such as non bridging oxygens (NBOs) and free spaces around Si–F bonding were proved to promote the hydrolysis and successive water adsorption. The structure required to initiate the hydrolysis reaction was the multiple F-substituted Si, in particular, =SiF2. In part 2, we attempt to show the possibility of suppressing the formation of =SiF2. The results of a Monte Carlo investigation corresponding to such as an F-ion implantation into SiO2 suggested the possibility of achieving higher doping of F with suppression of the formation of SiF x by modulating the probability of F substitution into SiO2.