High purity nano-crystalline carbon nitride films prepared at ambient temperature by ion beam sputtering

High purity nano-crystalline carbon nitride films have been successfully deposited by ion beam sputtering. A novel bio-molecular C–N compound, 6-aminopurine, of which the characteristic features include covalent C–N bonding, high N/C ratio and a six-membered ring structure similar to that in the hypothetical C 3N 4 crystal, has been employed as the target material. The films can be deposited onto a variety of substrates, such as copper, silver, stainless steel, nickel and silicon wafer at ambient temperature. SAM examination indicates a high nitrogen-to-carbon ratio at about 0.51. XPS, IR and Raman studies reveal that the chemical bonding structures consist mainly of sp 3 -hybridized carbon as well as sp 2 -hybridized nitrogen and carbon. Both TEM and SAM mapping investigations indicate that the film contains a very dense and homogenous distribution of nano-crystalline grains. However, the structures of these crystals are yet to be determined since their TEM diffraction patterns only matched partially with the calculated pattern for β-C 3N 4.