US 12,143,085 B2
Film bulk acoustic resonator structure and fabricating method
Jian Wang, Shenzhen (CN)
Assigned to Shenzhen Newsonic Technologies Co., Ltd., Shenzhen (CN)
Filed by Shenzhen Newsonic Technologies Co., Ltd., Shenzhen (CN)
Filed on Oct. 19, 2021, as Appl. No. 17/504,761.
Prior Publication US 2022/0103146 A1, Mar. 31, 2022
Int. Cl. H03H 3/02 (2006.01); H03H 9/02 (2006.01); H03H 9/13 (2006.01); H03H 9/17 (2006.01); H10N 30/02 (2023.01); H10N 30/063 (2023.01)
CPC H03H 3/02 (2013.01) [H03H 9/02015 (2013.01); H03H 9/131 (2013.01); H03H 9/171 (2013.01); H10N 30/02 (2023.02); H10N 30/063 (2023.02); Y10T 29/42 (2015.01); Y10T 29/49005 (2015.01)] 17 Claims
OG exemplary drawing
 
1. A method for fabricating a film bulk acoustic resonator (FBAR) structure, comprising:
sequentially forming a top electrode material layer, a piezoelectric layer, and a bottom electrode material layer on a substrate;
patterning the bottom electrode material layer to form a bottom electrode;
forming a sacrificial layer above the bottom electrode;
forming a trench in the sacrificial layer, the trench surrounding a portion of the sacrificial layer to be removed; and
forming a boundary layer above the sacrificial layer and within the trench;
forming a bottom bonding layer above the boundary layer, the bottom bonding layer including a protruding structure protruding towards the piezoelectric layer and surrounding the portion of the sacrificial layer to be removed;
after forming the bottom bonding layer, bonding a bottom cap wafer onto the sacrificial layer via the bottom bonding layer;
removing the substrate;
patterning the top electrode material layer to form a top electrode; and
removing the portion of the sacrificial layer surrounded by the protruding structure of the bottom bonding layer to form a lower cavity.