| CPC H04R 31/003 (2013.01) [B81C 1/00158 (2013.01); H04R 19/04 (2013.01); B81C 2201/0105 (2013.01); B81C 2201/0116 (2013.01); B81C 2201/0133 (2013.01); H04R 2201/003 (2013.01)] | 19 Claims |
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1. A preparation method for a micro-electromechanical systems (MEMS) microphone, comprising 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 of the plurality of acoustic holes having two openings, one of which communicating with the cavity and the other one located on the silicon surface of the silicon substrate;
forming a sacrificial layer on the silicon substrate, which comprises a first filling portion filling the cavity, a second filling portion filling the plurality of acoustic holes and a shielding portion shielding the silicon surface of the silicon substrate;
forming a polysilicon layer on a side of the shielding portion away from the silicon surface;
forming a recess in the silicon substrate on a side away from the silicon surface; and
removing the first filling portion, the second filling portion and part of the shielding portion of the sacrificial layer so that the recess is brought into communication with the cavity, resulting in the formation of 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.
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