LOW-TEMPERATURE ATMOSPHERIC-PRESSURE CHEMICAL VAPOR-DEPOSITION OF POLYCRYSTALLINE TIN NITRIDE THIN-FILMS

The atmospheric pressure chemical vapor deposition of tin nitride thin films from tetrakis(dimethylamido)tin(IV) and ammonia precursors is reported. The films were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, Rutherford backscattering spectrometry, and forward recoil spectrometry. The films were deposited on soda lime, borosilicate, and quartz glass and silicon substrates at substrate temperatures of 200-400-degrees-C with growth rates up to 1000 angstrom/min. The films were smooth, adherent, and chemically inert. Rutherford backscattering analysis showed that the N/Sn ratio was 1.45-1.50. The ratio was independent of deposition temperature. The hydrogen concentration, measured by forward recoil spectrometry, ranged from 18 atom % at 200-degrees-C to 15 atom % at 400-degrees-C. Transmission electron microscopy revealed that the films deposited at 200-degrees-C were amorphous whereas films deposited at 300 and 400-degrees-C were polycrystalline. The films were conductive with resistivities in the range of (2-9) X 10(-3) OMEGA-cm. A bandgap of 1.94-2.25 eV was estimated from transmission spectra.