Patent ID: 9681234
Date: 2017-06-13
CPC Classifications: B81B,B81C,H04R,H04S

Claim:
1. A MEMS microphone structure comprising: a semiconductor substrate having a cavity therein; a first dielectric layer formed on the semiconductor substrate having a through-hole communicating with the cavity; a lower diaphragm electrode formed above the through-hole and at least partially attached to an upper surface of the first dielectric layer, wherein the lower diaphragm electrode is lead out through a lower electrode connection; and an upper electrode structure with an insulating layer, wherein the upper electrode structure comprises an annular supporter, a back plate having multiple holes, and an upper electrode connection; wherein at least a part of the annular supporter extends downwardly to the lower diaphragm electrode while the rest of the annular supporter extends downwardly to the semiconductor substrate; the back plate is suspended above the lower diaphragm electrode by the annular supporter, forming an air gap therebetween; an upper electrode is embedded in the insulating layer at the back plate and is lead out by the upper electrode connection; wherein the annular supporter is an annular trench; the annular trench comprises a first portion formed outside the lower diaphragm electrode, the bottom of which extending to the semiconductor substrate; the insulating layer includes a first opening at the upper electrode connection; the upper electrode in the insulating layer at the back plate is continuously distributed and embedded in the insulating layer at the first portion of the annular trench and in the insulating layer at the upper electrode connection, and is exposed at the first opening.