Highly Oriented ZnO Thin Films Obtained with Low Temperature Annealing of Sol-Gel Coatings

The effect of the pre-heating temperature on the deposition of c-axis oriented thin ZnO films has been investigated, after fixing a low annealing temperature. The deposition process is optimized to be compatible with silicon/silicon-dioxide substrates, to make piezoelectric coatings for integrated smart sensors. Deposition is carried out on glass and oxidized silicon substrates. The dependence of the c-axis orientation on the pre-heating temperature has been studied by applying experimental design and response surface techniques. The films are synthesized by the sol-gel method. The effect of the deposition conditions on the characteristic (002) peak is determined by X-ray diffraction analysis. Surface uniformity and grain size is observed by SEM. It is observed that the pre-heating temperature has a strong effect on the orientation of the film.