MEMS microphone and preparation method therefor

    公开(公告)号:US12022270B2

    公开(公告)日:2024-06-25

    申请号:US17761669

    申请日:2020-05-26

    Abstract: A preparation method for a micro-electromechanical systems (MEMS) microphone includes the steps of: providing a silicon substrate having a silicon surface; forming an enclosed cavity in the silicon substrate; forming a plurality of spaced apart acoustic holes in the silicon substrate, each acoustic hole having two openings, one of which communicating with the cavity and the other one located on the silicon surface; forming a sacrificial layer on the silicon substrate, which includes a first filling portion, a second filling portion and a shielding portion; forming a polysilicon layer on the shielding portion; forming a recess in the silicon substrate on the side away from the silicon surface; and removing the first filling portion, the second filling portion and part of the shielding portion so that the recess is brought into communication with the cavity to form a back chamber, and that the polysilicon layer, the remainder of the shielding portion and the silicon substrate together delimit a hollow chamber, the hollow chamber communicating with the opening of the plurality of acoustic holes away from the cavity, completing the MEMS microphone.

    Micro-Electro-Mechanical System device

    公开(公告)号:US11671765B2

    公开(公告)日:2023-06-06

    申请号:US17422300

    申请日:2020-04-30

    Abstract: A Micro-Electro-Mechanical System (MEMS) device includes a substrate, and a first sacrificial layer, a first conductive film, a second sacrificial layer, and a second conductive film successively laminated on the substrate, the second sacrificial layer being provided with a cavity; and further includes an amplitude-limiting layer provided with a first through hole and an isolation layer provided with a second through hole. The amplitude-limiting layer is located between the first conductive film and the first sacrificial layer and the isolation layer is located between the amplitude-limiting layer and the first conductive film, and/or the amplitude-limiting layer is located on the second conductive film and the isolation layer is located between the amplitude-limiting layer and the second conductive film. The amplitude-limiting layer extends to a projection region of an opening of the cavity and is in a suspended state.

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