| Abstract
| - For all of the inorganic porous spin-on low-k films being developed today, a post-spin-on hydrophobictreatment is needed to reduce their moisture sensitivity. In the present work, we demonstrate that, forpure-silica-zeolite MFI spin-on low-k films, this extra hydrophobic treatment step can be potentiallyeliminated by using organic-functionalized pure-silica-zeolite MFI (OF PSZ MFI) nanoparticle suspension.Specifically, methyltrimethoxysilane was simply added to the synthesis solution for a PSZ MFI nanoparticlesuspension that contains tetraethyl orthosilicate, tetrapropylammonium hydroxide, ethanol, and water.This approach takes advantage of the hydrophobic methyl groups in the zeolite nanocrystal frameworkas well as in amorphous silica in the low-k film. The improvement of the hydrophobicity of the spin-onfilm from this OF PSZ MFI nanoparticle suspension was demonstrated by the higher water contact angleof the film and less moisture sensitivity of the k value in an ambient atmosphere.
- Dielectric constant (k) versus exposure time to air with 50−60% relative humidity: (a) nonsilylated PSZ MFI film; (b) OF PSZ MFI film calcined in nitrogen at 355 °C; (c) silylated PSZ MFI film.
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