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 with 300 keV Ar(+) at a fluence of 1 x 10(15) ions cm(-2), and annealing in vacuum in the temperature range 200-750 degrees C was performed on the as-deposited and irradiated samples. The film stoichiometry was determined by Rutherford back-scattering spectrometry and energy recoil detection analysis using a 2.0 MeV He(+) beam, while bond modifications were followed by infrared spectroscopy. Ion irradiation affects the thermal stability of the material; as-deposited films are stable up to 400 degrees C, and at higher temperature the material composition changes because of the hydrogen loss. The stability of irradiated samples is improved at about 150 degrees C; the difference is related to the structural changes induced by ion irradiation. The improvement of thermal stability induces a change in the luminescence properties of a-SiC : H. Correlation between the film composition and the luminescence properties is reported.