Method for manufacturing a micro-electro-mechanical microphone

摘要

A micro-electro-mechanical microphone and manufacturing method thereof are provided. The micro-electro-mechanical microphone includes a diaphragm, which is formed on a surface of one side of a semiconductor substrate, exposed to the outside surroundings, and can vibrate freely under the pressure generated by sound waves; an electrode plate with air holes, which is under the diaphragm; an isolation structure for fixing the diaphragm and the electrode plate; an air gap cavity between the diaphragm and the electrode plate, and a back cavity under the electrode plate and in the semiconductor substrate; and a second cavity formed on the surface of the same side of the semiconductor substrate and in an open manner The air gap cavity is connected with the back cavity through the air holes of the electrode plate The back cavity is connected with the second cavity through an air groove formed in the semiconductor substrate.

主权项

1. A method for manufacturing a micro-electro-mechanical microphone, comprising:
providing a semiconductor substrate; forming a first groove, a second groove and a connecting groove on a surface of the semiconductor substrate, the connecting groove joining the first groove and the second groove; forming a first sacrificial layer in the first groove; forming an electrode plate with air holes on the first sacrificial layer, the electrode plate stretching across the first groove and extending to the surface of the semiconductor substrate; forming a second sacrificial layer on the electrode plate, the second sacrificial layer connecting to the first sacrificial layer; forming a diaphragm on the second sacrificial layer; forming an isolation structure; and removing the first sacrificial layer and the second sacrificial layer.