Deposition of a hydrophobic lining layer has a surprising and unexpected result of converting subsequent hydrophilic layers to hydrophobic layers. [0078] The process gases for the gap filling layer 302 are preferably SiH4, CH3SiH3, or (CH3)2SiH2 and 50 wt % of hydrogen peroxide (H2O2) which is vaporized and mixed with an inert carrier gas, such as helium.