Design and fabrication of a novel single-chip MEMS capacitive microphone using slotted diaphragm

摘要

A novel single-chip microelectromechanical systems u0001MEMSu0002ncapacitive microphone with a slotted diaphragm for sound sensing isndeveloped to minimize the microphone size and improve the sensitivitynby decreasing the mechanical stiffness of the diaphragm. According tonthe results, a clamped microphone with a 2.43u00012.43-mm2 diaphragmnand a slotted one with a 1.5-u00011.5-mm2 diaphragm have the same me-nchanical sensitivity, but the size of slotted microphone is at least 1.62ntimes smaller than clamped structure. The results also yield a sensitivitynof 5.33u000110−6 pF/Pa for the clamped and 3.87u000110−5 pF/Pa for the slot-nted microphone with a 0.5u00010.5-mm2 diaphragm. The sensitivity of thenslotted diaphragm is increased 7.27 times. The calculated pull-in voltagenof the clamped microphone is 214 V, the measured pull-in voltage of thenslotted one is 120 V. The pull-in voltage of the slotted microphone isnabout 50% decreased