Patterning of self-assembly surfactant templated nanoporous silica thin film as an ultra low-k dielectric

We have studied dry etching characteristics of the the nanoporous silica dielectric using Ar/CHF/sub 3//CF/sub 4/ as the plasma gas source. Trimethylsilylation by hexamethyldisilazane (HMDS) vapor treatment is used to improve hydrophobicity of nanoporous silica dielectrics. During dry etch and resist ashing, hydrophobicity of the nanoporous silica thin films is destroyed, leading to serious degradation in the dielectric property.