THIN FILM PIEZOELECTRIC OSCILLATOR, THIN FILM PIEZOELECTRIC DEVICE, AND MANUFACTURING METHOD THEREOF

摘要

A thin film piezoelectric device includes a substrate (12) having a via hole (22) and a piezoelectric laminated structure (14) consisting of a lower electrode (15), a piezoelectric film (16), and an upper electrode (17) formed on the substrate (12) via an insulation layer (13). A plurality of thin film piezoelectric oscillators (210, 220) are formed for the via hole (22). The piezoelectric laminated structure (14) includes a diaphragm (23) located to face the via hole (22) and a support area other than it. The thin film piezoelectric oscillators (210, 220) are electrically connected by the lower electrode (15). When the straight line in the substrate plane passing through the centers (1, 2) of the diaphragm (23) of the thin film piezoelectric oscillators (210, 220) has the length D1 of the segment passing through the support area and the distance between the centers of the diaphragms of the thin film piezoelectric oscillators (210, 220) is D0, the ratio D1/D0 is 0.1 to 0.5. The via hole (22) is formed by the deep graving type reactive ion etching method.