Condenser microphone having flexure hinge diaphragm and method of manufacturing the same

Abstract

A micromini condenser microphone having a flexure hinge-shaped upper diaphragm and a back plate, and a method of manufacturing the same are provided. The method includes the steps of: forming a lower silicon layer and a first insulating layer; forming an upper silicon layer to be used as a back plate on the first insulating layer; forming a plurality of sound holes by patterning the upper silicon layer; forming a second insulating layer on the upper silicon layer; forming a conductive layer on the upper silicon layer having the sound holes, and forming a passivation layer on the conductive layer; forming a sacrificial layer on the passivation layer; depositing a diaphragm on the sacrificial layer, and forming a plurality of air holes passing through the diaphragm; forming electrode pads on the passivation layer and a region of the diaphragm; and etching the sacrificial layer, the passivation layer, the conductive layer, the upper silicon layer, the first insulating layer and the lower silicon layer to form an air gap between the diaphragm and the upper silicon layer. Consequently, due to the flexible diaphragm, a manufacturing process using semiconductor MEMS technology may improve the sensitivity of the condenser microphone and reduce the size of the condenser microphone, thereby enabling integration into a portable terminal.