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 two 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 and optical properties was carried out considering the most relevant deposition parameters, the dissipation power P(Al) of the Al source and the oxygen flow rate f(O(2)). The Al concentration in the films was found to increase with increasing P(Al) and to decrease with increasing f(O(2)). The films exhibited 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 was also observed. (C) 1999 Elsevier Science S.A. All rights reserved.