A method including introducing a precursor in the presence of a circuit substrate, and forming a film including a reaction product of the precursor on the substrate, wherein the precursor includes a molecule comprising a primary species of the film and a modifier. A method including introducing a precursor in the presence of a circuit substrate, the precursor including a primary species and a film modifier as a single source, and forming a film on the circuit substrate. An apparatus including a semiconductor substrate, and a film on a surface of the semiconductor substrate, the film including a reaction product of a precursor including a molecule comprising a primary species and a modifier.