The effect of thickness on the properties of Ti-doped ZnO films by simultaneous r.f. and d.c. magnetron sputtering

For Ti-doped ZnO (ZnO:Ti) films, the crystallinity and degree of orientation of the ZnO:Ti films were closely related to the film thickness. The crystal size increased with the increase of film thickness. With decreasing film thickness, there were more defects existing in the ZnO:Ti films and surface roughness decreased. The resistivity increased with the decrease of film thickness. The main scattering mechanism in the thin ZnO:Ti films was defect scattering. The transmission in UV region decreased strongly with the increase of film thickness. Such behavior was due to the films with different thickness showing different structural and electrical properties. As the results, film thickness affected the properties of ZnO:Ti films significantly.