Method of fabricating a MEMS microphone with trenches serving as vent pattern

摘要

A method of fabricating a MEMS microphone includes: first providing a substrate having a first surface and a second surface. The substrate is divided into a logic region and a MEMS region. The first surface of the substrate is etched to form a plurality of first trenches in the MEMS region. An STI material is then formed in the plurality of first trenches. Subsequently, the second surface of the substrate is etched to form a second trench in the MEMS region, wherein the second trench connects with each of the first trenches. Finally, the STI material in the first trenches is removed.

主权项

1. A method of fabricating a MEMS microphone, comprising:
providing a substrate comprising a first surface and a second surface, the substrate having at least a logic region and at least a MEMS region; etching the first surface of the substrate to form a plurality of first trenches within the MEMS region; before forming the first trenches, etching the first surface of the substrate to form at least one third trench in the logic region, wherein the step of forming the first trench and the third trench comprises:
forming a mask layer on the first surface of the substrate;performing a first patterning process to pattern the mask layer to form a first patterned mask layer;taking the first patterned mask layer as a first mask to etch part of the first surface within the logic region to form the third trench;performing a second patterning process to pattern the first patterned mask layer to form a second patterned mask layer; andtaking the second patterned mask layer as a second mask to etch part of the first surface within the MEMS region to form the first trenches; forming an insulating material in each of the first trenches; etching the second surface of the substrate to form a second trench in the MEMS region by taking the insulating material in the first trenches as an etching stop layer, wherein the second trench communicates with each of the first trenches; and removing the insulating material in each of the first trenches.