US 12,335,702 B2
Method for manufacturing MEMS acoustic sensor
Qiang Dan, Wuhan (CN); Chungmin Li, Taiwan (CN); KianHeng Goh, Batu Pahat (MY); Kahkeen Lai, Singapore (SG); and Yang Li, Wuhan (CN)
Assigned to AAC Kaitai Technologies (Wuhan) CO., LTD, Wuhan (CN)
Filed by AAC Kaitai Technologies (Wuhan) CO., LTD, Hubei (CN)
Filed on May 24, 2023, as Appl. No. 18/323,393.
Application 18/323,393 is a continuation of application No. PCT/CN2023/081085, filed on Mar. 13, 2023.
Claims priority of application No. 202310148526.3 (CN), filed on Feb. 20, 2023.
Prior Publication US 2024/0284131 A1, Aug. 22, 2024
Int. Cl. H04R 31/00 (2006.01); H04R 17/02 (2006.01); H10N 30/05 (2023.01); H10N 30/06 (2023.01)
CPC H04R 31/006 (2013.01) [H04R 17/025 (2013.01); H10N 30/05 (2023.02); H10N 30/06 (2023.02); H04R 2201/003 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method for manufacturing a MEMS acoustic sensor, comprising:
providing a substrate, and sequentially stacking a structural layer and a piezoelectric material layer on a side of the substrate;
performing photolithography modeling on the piezoelectric material layer and the structural layer sequentially to generate a first groove penetrating through the piezoelectric material layer and a second groove penetrating through the structural layer, respectively; wherein the first groove is arranged directly opposite to and in communication with the second groove to form a structural gap together;
stacking a polymer layer on a side of the piezoelectric material layer away from the substrate, and completely covering the first groove with the polymer layer;
etching the substrate in a direction from a side of the substrate away from the piezoelectric material layer towards the piezoelectric material layer, so that the substrate forms a cavity penetrating through the substrate, wherein the structural layer is covered on the side of the substrate close to the piezoelectric material layer to enable the second groove to be in communication with the cavity;
stacking a first part of a prefabricated jig on a side of the polymer layer away from the substrate, wherein an arch groove is defined on the first part to enable the arch groove to be arranged directly opposite to the structural gap; heating the jig, the substrate, the piezoelectric material layer, and the polymer layer together to a first temperature to enable the polymer layer to be in a rubbery state, wherein a first ventilation hole penetrating through the first part is further defined on the first part, the first ventilation hole is in communication with the arch groove and outside, and the first temperature is a glassy transition temperature of the polymer layer;
introducing air at a predetermined pressure into the cavity and controlling a pressure inside the cavity to reach a predetermined value, to enable a part of the polymer layer opposite to the arch groove to deform and adhere to an inner wall of the arch groove to form an arch portion;
maintaining an atmospheric pressure load of the air and cooling the air to below the first temperature, to enable the polymer layer to be in a glassy state; and
stop controlling the pressure inside the cavity and reducing the pressure inside the cavity, disassembling the jig, and cutting a wafer according to a preset shape to obtain the MEMS acoustic sensor.