US 11,870,419 B2
Bulk acoustic wave resonator
Won Han, Suwon-si (KR); Sang Uk Son, Suwon-si (KR); Tae Yoon Kim, Suwon-si (KR); Chang Hyun Lim, Suwon-si (KR); Sang Heon Han, Suwon-si (KR); and Jong Beom Kim, Suwon-si (KR)
Assigned to Samsung Electro-Mechanics Co., Ltd., Suwon-si (KR)
Filed by Samsung Electro-Mechanics Co., Ltd., Suwon-si (KR)
Filed on Apr. 5, 2021, as Appl. No. 17/222,018.
Claims priority of application No. 10-2020-0131876 (KR), filed on Oct. 13, 2020.
Prior Publication US 2022/0116016 A1, Apr. 14, 2022
Int. Cl. H03H 9/17 (2006.01)
CPC H03H 9/173 (2013.01) 22 Claims
OG exemplary drawing
 
1. A bulk acoustic wave resonator comprising:
a substrate;
a first electrode, wherein a cavity is formed between the substrate and the first electrode;
a piezoelectric layer disposed on the first electrode and overlapping at least a portion of the first electrode;
a second electrode disposed on the piezoelectric layer and overlapping at least a portion of the piezoelectric layer;
a passivation layer having at least a portion disposed on the second electrode and overlapping at least a portion of the second electrode; and
a lower frame spaced apart from the substrate and having a portion of the cavity disposed therebetween,
wherein any one of the second electrode and the passivation layer includes a protruding portion having a first thickness and an extended portion having a second thickness less than the first thickness, and
wherein an inner end of the lower frame and an end of the protruding portion are spaced apart in a horizontal direction.