SYNTHESIS OF CARBON-NITRIDE FILMS USING A FAST-SWITCHED DUAL-SOURCE LOW-ENERGY ION-BEAM DEPOSITION SYSTEM

Thin C(x)N(y) films were deposited in UHV using alternating low energy ion beams of C+ and N+ or N2+ in the energy range of 5 to 100 eV. The ion beam deposition system is equipped with two Freeman ion sources, mass analysis and fast automated beam switching, allowing perpendicula r bombardment of the target with a single ion beam at a time. The comp osition and density of the films were studied by AES (in situ), XPS an d RBS. The dependence of the film properties and growth mechanisms on ion energy, beam switching rate, and C-to-N arrival ratio have been in vestigated. The influence of the deposition parameters on the film sto ichiometry is discussed. Exposure of the film to atmosphere leads to o xygen incorporation, resulting in a lowered surface concentration of n itrogen. The XPS N ls and C ls binding energies vary in a relatively b road range indicating that several bond states may be present. The inf luence of the substrate material on film growth has also been studied. On Si{100}, film growth commences with the formation of an interfacia l silicon nitride. No film growth was observed on gold, however deposi tion was possible on tantalum and molybdenum.