Ion-beam processing of hydrogenated amorphous silicon carbide grown by plasma-enhanced chemical vapour deposition

Ion irradiation of amorphous hydrogenated silicon carbide (a-SiC : H) films prepared by plasma-enhanced chemical vapour deposition changes its thermal stability and the luminescence properties. The samples were irradiated wit h 300 keV Ar+ at a fluence of 1 x 10(15) ions cm(-2), and annealing in vacu um in the temperature range 200-750 degrees C was performed on the as-depos ited and irradiated samples. The film stoichiometry was determined by Ruthe rford back-scattering spectrometry and energy recoil detection analysis usi ng a 2.0 MeV He+ beam, while bond modifications were followed by infrared s pectroscopy. Ion irradiation affects the thermal stability of the material; as-deposited films are stable up to 400 degrees C, and at higher temperatu re the material composition changes because of the hydrogen loss. The stabi lity of irradiated samples is improved at about 150 degrees C; the differen ce is related to the structural changes induced by ion irradiation. The imp rovement of thermal stability induces a change in the luminescence properti es of a-SiC : H. Correlation between the film composition and the luminesce nce properties is reported.