Piezoelectric thin film element, method for manufacturing the same, and electronic device including piezoelectric thin film element

A method for manufacturing an alkali-niobate-based piezoelectric thin film element, comprising:

• a lower-electrode-film forming step of forming a lower electrode film on a substrate;
• a piezoelectric-thin-film forming step of forming a piezoelectric thin film on the lower electrode film, the piezoelectric thin film comprising an alkali-niobate-based piezoelectric material represented by the formula (NaxKyLiz)NbO3, where 0≦x≦1, 0≦y≦1, 0≦z≦0.2, and x+y+z=1;
• an etching-mask-pattern forming step of forming a desired pattern of an etching mask on the piezoelectric thin film;
• and
• a piezoelectric-thin-film etching step of dry-etching the piezoelectric thin film into a desired pattern,
• wherein the etching mask comprises an oxide at least in a layer adjacent to the piezoelectric thin film.