Surface morphologies of TiOx films deposited on 304L-SS substrate by an Ar+-ion-beam-assisted reactive deposition (Ar+-IBARD) method were investigated with respect to the Ar+-ion-current density and the substrate species, in order to clarify the effects of Ar+-ion bombardment on film growth. The TiOx film obtained at an ion-current density of 5 mu A cm(-2) was polycrystalline (rutile-type) with a smooth surface and a uniform cross-sectional structure. The films obtained at higher ion-current densities (15 and 30 mu A cm(-2)) were also polycrystalline (rutile-type) but showed a rough surface with a columnar cross-sectional structure, Film generated without Ar+-ion bombardment was amorphous with relatively uniform cross-sectional structure. No significant differences were observed, however, between the surface morphologies of the TiOx films on 6 substrates of (304L-SS, Si(100), SnO2, MgO(100), quartz, glass and titanium). Therefore, a higher flux of Ar+-ion bombardment accelerates crystallization processes.