Home – Home – Jornals – Journal of Structural Chemistry 2009 number 4

Using MM2 molcular mechanics simulation and MNDO/PM3 semiempirical methods we show that the most probable mechanism of surface modification of alkyl-doped silicon dioxide layers in plasma is the interaction with СН₃ groups. Detachment of the hydrogen atom causes a change in the character of Si-O-Si bonding, which results in an increase in the number of Si-O-Si groups with an angle in a range of 144° to 146°. Subsequent treatment in ammonia plasma leads to pore sealing through the formation of -CH-Si-O-Si-O-Si-O-Si- chains. The mechanism proposed provides a good explanation to FTIR experimental spectra and to changes in the reactivity of porous layers after treatment in helium plasma.