ION POLISHING OF ZNO FILMS BY AN ECR SYSTEM

SAW filters in the ZnO/IDT/glass type have periodic convexes of the same thickness as the IDT electrodes caused by the presence of IDT on the ZnO film surface and fine irregularities all over the ZnO film surface. These unevenness affects the SAW velocity dispertion. An attempt to smooth the unevenness, using the inclination effect in the ion polishing process, resulted in observation of an interesting surface smoothing phenomenon such as narrowing of the width of convex portions caused by IDT on ZnO film surface, smoothing of small convex spots of fine irregularities found all over the ZnO film surface, etc.