PIEZOELECTRIC THIN FILM DEVICE

摘要

A piezoelectric thin film device which is composed mainly of a substrate, a piezoelectric thin film formed on the substrate, and thin film electrodes formed on both the upper and lower surfaces of the thin film. The thin film is resonated by applying an AC voltage across the electrodes. A substrate removed section is formed by partially or entirely removing the substrate below the thin film and opened to both the front and rear surfaces of the substrate through openings so as to relieve the pressure variation in the substrate removed section below a resonant structure.