BULK ACOUSTIC WAVE RESONATOR AND MANUFACTURING METHOD OF THE SAME

To provide a bulk acoustic wave resonator that can form a piezoelectric film on a surface of a lower layer electrode with a flat surface and improve its characteristics.SOLUTION: The bulk acoustic wave resonator includes a support substrate and a lower layer electrode film 2, a piezoelectric film 3, and an upper layer electrode film 4 stacked on the support substrate. The lower layer electrode film 2 has a flat surface. The piezoelectric film 3 is stacked on the lower electrode film 2. A recess 7 is provided on a surface of the periphery, and a part of the surface is cut out. The upper layer electrode film 4 covers the recess 7 and is stacked on top of the piezoelectric film 3.SELECTED DRAWING: Figure 5 【課題】平坦な表面を有する下層電極表面に圧電膜を形成し、特性向上を図ることができるバルク弾性波共振器を提供する。【解決手段】支持基板と、該支持基板上に積層した下層電極膜２、圧電膜３および上層電極膜４とを備えたバルク弾性波共振器において、下層電極膜２は表面が平坦であり、圧電膜３は下層電極膜２上に積層し、周縁部の表面に、該表面の一部を切り欠いた凹部７を備え、上層電極膜４は凹部７を被覆し、圧電膜３上に積層する。【選択図】図５