US 12,070,773 B2
Adaptive cavity thickness control for micromachined ultrasonic transducer devices
Lingyun Miao, Fremont, CA (US); Jianwei Liu, Fremont, CA (US); and Keith G. Fife, Palo Alto, CA (US)
Assigned to BFLY OPERATIONS, INC, Burlington, MA (US)
Filed by BFLY OPERATIONS, INC., Burlington, MA (US)
Filed on Jan. 20, 2023, as Appl. No. 18/099,456.
Application 18/099,456 is a division of application No. 16/683,750, filed on Nov. 14, 2019, granted, now 11,583,894.
Claims priority of provisional application 62/810,358, filed on Feb. 25, 2019.
Prior Publication US 2023/0149977 A1, May 18, 2023
Int. Cl. B06B 1/02 (2006.01); B81B 3/00 (2006.01); B81C 1/00 (2006.01)
CPC B06B 1/0292 (2013.01) [B81B 3/0021 (2013.01); B81C 1/00158 (2013.01); B81B 2201/0271 (2013.01); B81B 2203/0127 (2013.01); B81B 2203/0315 (2013.01); B81B 2203/04 (2013.01); B81C 2201/0125 (2013.01); B81C 2201/013 (2013.01); B81C 2201/0176 (2013.01); B81C 2203/03 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An ultrasonic transducer device, comprising:
a patterned film stack disposed on first regions of a substrate, the patterned film stack comprising a metal electrode layer and a bottom cavity layer formed on the metal electrode layer;
a planarized insulation layer disposed on second regions of the substrate layer;
a cavity formed in a membrane support layer and a CMP stop layer, the CMP stop layer comprising a top layer of the patterned film stack and the membrane support layer formed over the patterned film stack and the planarized insulation layer; and
a membrane bonded to the membrane support layer, wherein the CMP stop layer underlies portions of the membrane support layer but not the cavity.