Deposition of highly oriented low-stress ZnO films

Several-micron-thick layers of ZnO films were deposited on glass substrates. The films were grown by reactive DC magnetron sputtering from a zinc target. The films are highly oriented, as indicated by X-ray diffraction analysis, and the C-axis of the films is normal to the substrate. A moire deflectometer was built to determine the film stress by measuring the substrate curvature. The films have relatively low stress at higher deposition pressures. The acoustic coupling constant, k/sub t/, of the films was measured to be as high as 0.26, which is 90% the value for single-crystal ZnO. The dependence of film quality and stress on various deposition parameters such as pressure and power is presented.>