Method for manufacturing a piezoelectric film wafer, piezolelectric film element, and piezoelectric film device

摘要

A method for manufacturing a piezoelectric film wafer includes an etching step for carrying out a dry etching on a piezoelectric film formed on a substrate by using a gas containing Ar, and a step of changing a rate of the dry etching by detecting a change in an emission peak intensity of Na in emitted ion plasma the piezoelectric film. The piezoelectric film is made of an alkali niobate-based perovskite structure expressed in a composition formula (K1-xNax)NbO3 (0.4≦̸x≦̸0.7).