Capacitance type MEMS sensor

A capacitance type MEMS sensor, comprising:

• a first electrode portion;
• a second electrode portion facing the first electrode portion;
• and
• a semiconductor substrate having a recess dug in a thickness direction of the semiconductor substrate, the recess having sidewalls being a portion of the semiconductor substrate defining an inner surface of the recess, one of the sidewalls being the first electrode portion;
• wherein the second electrode portion is a diaphragm, the entire diaphragm arranged within the recess to be in parallel with and face the first electrode portion in a posture extending along a depth direction of the recess and to divide an internal space of the recess into a first space positioned at a side of the first electrode portion and a second space positioned at an opposite side of the first electrode portion, the diaphragm having a lower edge spaced apart from a bottom surface of the recess, the diaphragm being made of the same material as the semiconductor substrate;
• and
• wherein insulating films are arranged at longitudinal opposite sides of the diaphragm to join the longitudinal opposite sides of the diaphragm to the sidewalls other than the sidewall serving as the first electrode portion of the recess, the insulating films being interposed between the diaphragm and the sidewalls, and the insulating films electrically isolating the diaphragm from the semiconductor substrate.