Molecular design of ultralow-k insulator materials

Dielectric materials with low permittivity (low k) are required for insulation to reduce the interconnect RC-delay in deep submicron integrated circuits. Combinations of classical and quantum-theoretical approaches for the assessment of the dielectric properties of fullerene-based materials with the goal to find ultralow-k dielectrics with suitable mechanical properties were used. We study the covalent linking of C60 molecules and vary the length and chemical composition of the linker molecule as well as the linkage geometry. The (static) electric permittivities, k, and elastic bulk moduli, B, of the proposed materials are in the range of 1.7-2.2 and 5-23 GPa, respectively.