Transparent conductive ZnO : Al films by reactive co-sputtering from separate metallic Zn and Al targets

ZnO:Al films were deposited by reactive d.c. magnetron co-sputtering from t wo separate metallic targets of Zn and Al in an Ar/O-2 atmosphere. A first study of the Al incorporation, of the film morphology, of the electrical an d optical properties was carried out considering the most relevant depositi on parameters, the dissipation power P-Al of the Al source and the oxygen f low rate f(O-2). The Al concentration in the films was found to increase wi th increasing P-Al and to decrease with increasing f(O-2). The films exhibi ted a textured columnar structure within a well defined range of P-Al and f (O-2) where the optimum for high optical transmission and low resistivity w as also observed. (C) 1999 Elsevier Science S.A. All rights reserved.