BULK ACOUSTIC WAVE RESONATOR AND METHOD OF MANUFACTURING THE SAME

• Main Authors: LEE MOON CHUL, GIL JAE HYOUNG, KIM YONG SUK, LIM CHANG HYUN, LEE SUNG JUN
• Format: Patent
• Language: English; Japanese
• Published: 21.11.2019
• Subjects: BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS

To provide a bulk acoustic wave resonator and a method of manufacturing the same that are capable of inhibiting an abnormal notch caused by a thickness gradient formed over a wide region of a passivation layer.SOLUTION: A bulk acoustic wave resonator 100 includes: a substrate 110; a membrane layer 140 which together with the substrate forms a cavity; a lower electrode 150 disposed on the membrane layer; a piezoelectric layer 160 disposed to cover at least a portion of the lower electrode; an upper electrode 170 disposed to cover at least a portion of the piezoelectric layer; and a passivation layer 190 disposed to cover at least a portion of the upper electrode, where the passivation layer includes a non-trimming-processed portion disposed outside an active region in which the lower electrode, the piezoelectric layer and the upper electrode overlap, and having a thickness that is thicker than a thickness of a portion disposed on the active region.SELECTED DRAWING: Figure 1 【課題】パッシベーション層の厚さ勾配が広い領域に渡って形成されることによって生じる異常なノッチの発生を抑制することができるバルク音響共振器及びその製造方法を提供する。【解決手段】バルク音響共振器１００は、基板１１０と、基板とともにキャビティを形成するメンブレン層１４０と、メンブレン層上に配置される下部電極１５０と、下部電極の少なくとも一部を覆うように配置される圧電層１６０と、圧電層の少なくとも一部を覆うように配置される上部電極１７０と、上部電極を覆うように配置されるパッシベーション層１９０と、を含む。パッシベーション層は、下部電極、圧電層及び上部電極のすべてが重なるように配置される活性領域の外側に配置され、活性領域上に配置される部分の厚さよりも厚いトリミング未進行部を備える。【選択図】図１