Zinc oxide piezoelectric crystal film on sapphire plane

摘要

When a zinc oxide piezoelectric crystal film is epitaxially grown on an R-plane sapphire substrate by sputtering, a target containing not more than 4.5 percent by weight of Cu with respect to the total content of Zn and Cu is employed so that the zinc oxide piezoelectric film contains Cu. Thus, it is possible to obtain a zinc oxide piezoelectric crystal film having excellent orientation.