CAPACITANCE TYPE SENSOR, ACOUSTIC SENSOR, AND MICROPHONE

摘要

A chamber that penetrates vertically is formed in a silicon substrate. A diaphragm is arranged on the upper surface of the silicon substrate so as to cover the upper opening of the chamber. The diaphragm is divided by slits into a region located above the chamber (first diaphragm) and a region located above the upper surface of the silicon substrate (second diaphragm). A fixed electrode plate is arranged above the first diaphragm, and a low-volume first acoustic sensing portion is formed by the first diaphragm and the fixed electrode plate. Also, a high-volume second acoustic sensing portion is formed by the second diaphragm and the upper surface (electrically conducting layer) of the silicon substrate.

主权项

1. A capacitive sensor comprising:
a substrate having a cavity that is open at least at an upper surface; a vibrating electrode plate formed above the substrate so as to cover an upper portion of the cavity; a back plate formed above the substrate so as to cover the vibrating electrode plate; and a fixed electrode plate provided on the back plate, wherein the vibrating electrode plate is divided into a region located above the cavity and a region located above an upper surface of the substrate, a first sensing portion is formed by the fixed electrode plate and the region of the vibrating electrode plate located above the cavity, and a second sensing portion is formed by the upper surface of the substrate and the region of the vibrating electrode plate located above the upper surface of the substrate.