SILICON MICROPHONE COMPRISING ELECTRET VIBRATION PLATE

摘要

PURPOSE: A silicon microphone comprising an electret vibration plate is provided, which forms an electret by injecting charges into a silicon inorganic vibration plate and thus can improve a fabrication yield by reducing an assembly process. CONSTITUTION: An electret vibration plate(110) comprises a vibration film(112) and the first semiconductor wafer(113) and a spacer(114). The vibration film converts a sound pressure into an electrical signal by being vibrated by the sound pressure when the electret vibration plate is charged. The first semiconductor wafer is stacked on one side of the vibration film, and an inner circumference of the first semiconductor wafer is formed anisotropically by a wet etching. And the spacer is stacked on another side of the vibration film and forms an air gap(140) between a bottom surface of the second semiconductor wafer(130) and a bottom surface of the vibration film constituting the electret vibration plate.