Improved ITO thin films with a thin ZnO buffer layer by sputtering

In this paper, we report a buffering method of improving the quality of ITO thin films on glass by r.f. magnetron sputtering. By applying a ZnO buffer before the ITO deposition in the same run of sputtering, ITO films showed single (111)-oriented highly textured structure, while ITO films showed mix ed-oriented polycrystalline structure on bare glass. A design of experiment was taken out to minimize the resistivity of ITO films in the deposition p arameter space (oxygen ratio, total gas pressure, and temperature). Resista nce measurements showed that the ITO films with ZnO buffers had a remarkabl e 50% decrease of resistivity comparing to those without ZnO buffers at opt imized deposition condition. Room-temperature Hall effect measurements show ed that the decrease in resistivity comes from a large increase of mobility and a slight increase of carrier density after forming gas annealing. The ZnO/glass may be a good alternative substrate to bare glass for producing h igh quality ITO films for advanced electro-optic applications. (C) 2000 Els evier Science S.A. All rights reserved.