Materials with tunable low-k dielectric constant derived from functionalized octahedral silsesquioxanes and spherosilicates

Linked octahedral silsesquioxanes and spherosilicates offer a unique approach to tailor materials with low dielectric constants. The key lies in the design of the linking structures, which is determined by the nature of the hydrolyzable alkoxysilyl groups in the monomer. Thus, the molecular structure of the monomers influences structural, dielectric, and mechanical properties of the spin-coated polymer films via the number of alkoxysilyl groups introduced. Dielectric constants and hardness can be tuned in the range k = 2.4–3.0 and 0.20–0.85 GPa, respectively. With the use of a porogen, a dielectric constant as low as 1.9 is achieved.