To provide a pressure sensing device with a thin profile that can be small-sized while maintaining high performance and to provide a manufacturing method for a semiconductor substrate used for the device.
By providing a back electrode 5 to a bottom side 4a of a recessed part 4 formed to the center of a major side 3a of the semiconductor substrate 3 and fixing a circumferential edge of a vibration electrode film 7 onto a circumferential surface 3c spread around the recessed part 4 a capacitor comprising the back electrode 5, a space 8 (air) and the vibration electrode film 7 are configured. Since etching is adopted to form the recessed part 4, dispersion in the depth of the recessed part 4 in respective devices can be suppressed, resulting that the inexpensive pressure sensing device with high reliability can be obtained.
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