Spin-on Low-K materials are potentially very attractive as interconnectionmaterials in a wide range of semiconductor structures. In this work, neworganic-inorganic hybrid materials synthesized by vinylsilane polymerizationwere proposed. According to compositions and additional fabrications,dielectric constants of these materials were evaluated to be 2.3∼3.1. Thehardness was 2.0GPa after 430°C curing. These materials had good adhesionstrength such that fracture toughness on silicon wafer was 0.22 MPam0.5 without any adhesion promoters. This result indicatesthat these organicinorganic hybrid materials are very promising candidatesfor low-K dielectrics.