ABSTRACT
This chapter presents an electromagnetic comprehensive study of a new micromachined microphone performed in microelectromechanical systems (MEMS) technology. It serves to develop an electromagnetic analysis theory that can serve as a model in several MEMS magnetic sensors based. The chapter summarizes an overview of different MEMS microphone principles. The piezoresistive microphones have the advantage of using a simple manufacturing process and are easily integrated into semiconductor devices. The piezoelectric microphones may have the same design as piezoresistive ones except that the materials used generate electrical charge on its surface instead of a resistive change. It concludes a detailed theoretical magnetic modelling of a new monolithic electrodynamic complementary metal oxide semiconductor-MEMS microphone structure. Several approaches have been detailed, leading to determine the induced voltage expression in different biasing modes. This theory allowed us to estimate the theoretical expected output voltages range obtained in the MEMS electrodynamic microphone output.
