Development of High Fracture Toughness MEMS Microphone Using Pd‐Based Metallic Glass Membrane

ABSTRACT Capacitive‐type MEMS microphone with an amorphous solid structure membrane of PdCuSi metallic glass has been developed to suppress crack propagation and fracture against applied impact of air burst/air blow which was an issue with conventional poly‐Si thin membranes. High fracture toughness, low LFRO (low‐frequency roll‐off), and high SNR characteristics were simultaneously confirmed for the prototype, showing the air burst resistance of more than twice that of conventional poly‐Si membrane at the measurement limit of 0.97 MPa or more, the LFRO of 10 Hz or less, and the SNR of 69 dBV.