X-RAY STRUCTURE STUDIES OF TEXTURED ZINC OXIDE FILMS FOR SURFACE ACOUSTIC WAVE DEVICES.

X-ray methods are used to study the structure of textured zinc oxide films fabricated by reactive triode sputtering at constant current. It is shown that for substrate temperatures APP 1STH 623 K, the ZnO films that precipitate are stoichiometrically deficient in oxygen in an argon-oxygen sputtering atmosphere at pressure P equals 0. 066 Pa containing 20% oxygen. This deficiency is responsible for the mechanical stresses observed in the films. It was possible by increasing the pressure to 0. 13 Pa and raising the oxygen content to 50% to deposit ZnO films of stoichiometric composition. Also investigated is the possibility of increasing the deposition rate for normally oriented films by having the target closer to the substrate holder and decreasing the electric field produced in the surface layer of the fused quartz substrate during preliminary irradiation by ionizing gamma rays.