Development of High Fracture Toughness MEMS Microphone using Pd-based Metallic Glass Membrane

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.