PIEZOELECTRIC FILM DEVICE

摘要

Disclosed is a piezoelectric film device (10) comprising a substrate (11), a lower electrode (12), a piezoelectric film (15) and an upper electrode (16). The substrate (11) comprises a thin diaphragm portion (11a) and a thick portion (11b) surrounding the diaphragm portion. The lower electrode (12) is so formed on the substrate (11) as to extend over the thin diaphragm portion (11a) and the thick portion (11b). The piezoelectric film (15) is formed on the lower electrode (12). The upper electrode (16) is so formed on the piezoelectric film (15) as to face the thin diaphragm portion (11a), and comprises an upper electrode main body (16a) and a connecting portion (16b). The upper electrode main body (16a) has a planar shape generally analogous to that of the thin diaphragm portion (11a).