THIN FILM BULK ACOUSTIC RESONATOR AND ITS MANUFACTURING METHOD

PROBLEM TO BE SOLVED: To provide a thin film bulk acoustic resonator wherein floating and exfoliation of a film of an acoustic mirror layer for reducing acoustic leakage in the longitudinal direction are suppressed. SOLUTION: The thin film bulk acoustic resonator is provided with: a support substrate 1; a vibrator 2 formed by clamping a piezoelectric layer 5 between a lower electrode 4 and an upper electrode 6; and an acoustic mirror layer 3 including a first acoustic mirror material film 7 and a second acoustic mirror material film 8 whose acoustic impedance is higher than that of the first acoustic mirror material film 7. Then the vibrator 2 is supported on the support substrate via the acoustic mirror layer. The acoustic mirror layer is formed by using the first acoustic mirror material film, the second acoustic mirror material film, and one or more of acoustic mirror unit layers 3a each including an adhesive film 9 for enhancing the adhesiveness of the mirror material films. COPYRIGHT: (C)2007,JPO&INPIT