Patent ID: 8129803
Filing Date: 2012-03-06
Classification: B81B,B81C,H01L,H04R

Abstract:
1. A method for producing a micromachined microphone from a wafer having at least a first silicon layer, the method comprising: forming trenches through the first silicon layer; depositing a first oxide layer covering the front side of the first silicon layer and lining the trenches; forming a plurality of sacrificial polysilicon microphone structures on the first oxide layer; depositing a second oxide layer over the first oxide layer and the sacrificial polysilicon microphone structures; forming a plurality of polysilicon microphone structures including a diaphragm on the second oxide layer; removing the sacrificial polysilicon microphone structures; and removing a portion of at least one oxide layer underlying the plurality of polysilicon microphone structures from a back side of the first silicon layer through the trenches.