The growth of thinSi80C20diamond-structured material on (100)Si has been achieved using the novel C–H free, carbon source tetrasilyl methane,C(SiH3)4.The precursor decomposes at temperatures in the range 600–700 °C to give thin amorphous layers with a composition ofSi0.80C0.20,which corresponds to the same relative concentrations of Si and C as in the precursor. The amorphous material is crystallized via solid-phase epitaxy by annealing at 825 °C to yield a potentially ordered structure in whichSi4Ctetrahedra are linked together in a three-dimensional diamond-cubic framework. Measured lattice parameters are larger than expected from Vegards’ Law, a discrepancy which is attributed to steric repulsions causing bond elongation. ©1998 American Institute of Physics.