Microphone with aligned apertures

Abstract

A MEMS microphone has a backplate with a given backplate aperture, and a diaphragm having a diaphragm aperture. The given backplate aperture is substantially aligned with the diaphragm aperture.

What is claimed is: 
     
         1 . A method of forming a MEMS microphone, the method comprising:
 providing a backplate;   forming a diaphragm spaced from the backplate, the diaphragm forming a diaphragm aperture; and   forming a plurality of backplate apertures, a given aperture of the backplate apertures being at least partially aligned with the diaphragm aperture.   
     
     
         2 . The method as defined by  claim 1  wherein the given aperture is substantially aligned with the diaphragm aperture. 
     
     
         3 . The method as defined by  claim 1  wherein the plurality of backplate apertures includes a second aperture that is offset from the diaphragm aperture. 
     
     
         4 . The method as defined by  claim 1  wherein forming a diaphragm comprises:
 depositing a deposition material onto a sacrificial material supported by the backplate; 
 forming a plurality of springs; and 
 removing the sacrificial material to form the diaphragm, the plurality of springs suspending the diaphragm, the diaphragm being vertically spaced from the backplate. 
 
     
     
         5 . The method as defined by  claim 1  wherein providing a backplate comprises forming the backplate from an SOI wafer. 
     
     
         6 . The method as defined by  claim 1  wherein forming a plurality of backplate apertures includes etching a slot through a wafer.