US 12,263,506 B2
Anti-stiction bottom cavity surface for micromachined ultrasonic transducer devices
Lingyun Miao, Fremont, CA (US); Keith G. Fife, Palo Alto, CA (US); Jianwei Liu, Fremont, CA (US); and Jonathan M. Rothberg, Guilford, CT (US)
Assigned to BFLY Operations, Inc, Burlington, MA (US)
Filed by BFLY OPERATIONS, INC., Burlington, MA (US)
Filed on Dec. 6, 2023, as Appl. No. 18/530,629.
Application 18/530,629 is a continuation of application No. 18/093,701, filed on Jan. 5, 2023, granted, now 11,883,845.
Application 18/093,701 is a continuation of application No. 16/683,652, filed on Nov. 14, 2019, granted, now 11,571,711, issued on Feb. 7, 2023.
Claims priority of provisional application 62/810,358, filed on Feb. 25, 2019.
Claims priority of provisional application 62/768,048, filed on Nov. 15, 2018.
Prior Publication US 2024/0100566 A1, Mar. 28, 2024
Int. Cl. B06B 1/02 (2006.01); B81B 3/00 (2006.01); B81C 1/00 (2006.01)
CPC B06B 1/0292 (2013.01) [B81B 3/001 (2013.01); B81C 1/00984 (2013.01); B81B 2203/0127 (2013.01); B81B 2203/0315 (2013.01); B81B 2203/0392 (2013.01); B81C 2201/0109 (2013.01); B81C 2201/0125 (2013.01); B81C 2201/0176 (2013.01)] 20 Claims
OG exemplary drawing
 
11. A An ultrasonic transducer device made by a process comprising the steps of:
depositing a first layer on a substrate;
patterning the first layer at a region corresponding to a location of a transducer cavity;
conformally depositing an additional layer of a same type as the first layer on the first layer and exposed portions of the substrate;
conformally depositing a second layer on the additional layer of the same type as the first layer;
conformally depositing a third layer on the second layer;
conformally depositing a fourth layer on the third layer;
planarizing the fourth layer to a top surface of the third layer;
depositing a membrane support layer;
defining the transducer cavity in the support layer, wherein exposed portions of the third layer and the fourth layer are removed;
bonding a membrane to the support layer.