Piezoelectric thin-film resonator and filter and fabricating method

摘要

A piezoelectric thin-film resonator includes a device substrate (41) and a laminated body provided on the device substrate and composed of a lower electrode (43), an upper electrode (45) and a piezoelectric film (44) sandwiched between the lower and upper electrodes. The laminated body has a membrane portion in which the upper and lower electrodes overlap with each other through the piezoelectric film, and a gap (42) has a dome shape being formed between the device substrate and the lower electrode and located below the membrane portion. <IMAGE>