A method of depositing a material on a surface is disclosed. The method includes focusing a radiation beam on the surface and introducing a precursor gas near the surface wherein the precursor gas forms the material on the surface upon radiation by the radiation beam. The method further includes introducing an assistant gas near the surface wherein the assistant gas produces nitric oxide radicals upon radiation by the radiation beam. The nitric oxide radicals facilitate the dissociation process of the precursor gas and reduce contaminants in the deposited material.