US 12,068,733 B2
Fabrication method of film bulk acoustic resonator (FBAR) filter device
Jian Wang, Shenzhen (CN); Jie Zou, Shenzhen (CN); and Gongbin Tang, Shenzhen (CN)
Assigned to Shenzhen Newsonic Technologies Co., Ltd., Shenzhen (CN)
Filed by Shenzhen Newsonic Technologies Co., Ltd., Shenzhen (CN)
Filed on Sep. 25, 2023, as Appl. No. 18/473,670.
Claims priority of application No. 202310969496.2 (CN), filed on Aug. 2, 2023.
Prior Publication US 2024/0063768 A1, Feb. 22, 2024
Int. Cl. H03H 3/02 (2006.01); H03H 9/17 (2006.01); H03H 9/54 (2006.01)
CPC H03H 3/02 (2013.01) [H03H 9/171 (2013.01); H03H 9/54 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method for fabricating a film bulk acoustic resonator (FBAR) filter device including at least a first resonator and a second resonator, the method comprising:
determining a simulation target thickness of each one of a first electrode of the first resonator and a first electrode of the second resonator based on a target performance parameter of the FBAR filter device;
forming the first electrode of the first resonator and the first electrode of the second resonator on a first surface of a piezoelectric layer, wherein the forming includes:
forming the first electrode of the first resonator with a thickness that is greater than the simulation target thickness of the first electrode of the first resonator; and
forming the first electrode of the second resonator with a thickness that is the same as the simulation target thickness of the first electrode of the second resonator;
forming a first passivation layer of each one of the first resonator and the second resonator on a corresponding one of the first electrode of the first resonator and the first electrode of the second resonator;
forming a second electrode of each one of the first resonator and the second resonator on a second surface of the piezoelectric layer, the second surface being opposite to the first surface;
conducting a radio frequency (RF) performance test on the FBAR filter device;
adjusting a thickness of the second electrode of the first resonator based on a result of the RF performance test; and
forming a second passivation layer of each one of the first resonator and the second resonator on a corresponding one of the second electrode of the first resonator and the second electrode of the second resonator.