SURFACE-MORPHOLOGY AND RESISTIVITY OF ALUMINUM-OXIDE FILMS PREPARED BY PLASMA CVD COMBINED WITH ION-BEAM IRRADIATION

Plasma CVD combined with simultaneous ion beams has been developed in order to prepare ceramic insulating films which have strong force of a dhesion and higher electric resistivity at high temperatures. Aluminum oxide (Al2O3) films were deposited on nickel based superalloy (Incone l 718) by thermal CVD, plasma CVD and ion beam assisted plasma CVD at the several substrate temperatures. The surface morphology of these fi lms was analyzed by X-ray diffraction (XRD) and scanning electron micr oscopy (SEM). It was confirmed that, by ion beam irradiation, the exte nt of crystallization was enhanced at lower substrate temperature and grain size became smaller. The electric resistivity was measured in th e temperature range of RT to 800 degrees C., The film, deposited jy io n beam assisted plasma CVD at 800 degrees C, had higher electric resis tivity than the films by conventional CVD.