Semiconductor device and manufacturing method thereof

A semiconductor device whose main surface contains a sensor region formed from multiple sensor cells, comprising:

• a semiconductor substrate;
• a patterned second conducting layer formed on the semiconductor substrate;
• a first insulating film formed to cover the second conducting layer on the semiconductor substrate;
• a second insulating film formed on the first insulating film;
• a patterned first conducting layer formed on the second insulating film;
• a third insulating film formed to cover the first conducting layer on the second insulating film;
• and
• a fourth insulating film formed on the third insulating film,
• wherein each of the multiple sensor cells in the sensor region includes:
• a second electrode formed from the second conducting layer;
• a first electrode formed from the first conducting layer to face the second electrode;
• and
• a first cavity formed between the first electrode and the second electrode, and between the first insulating film and the second insulating film,
• wherein a first opening is formed on the second and the third insulating films to reach the first cavity by penetrating through the second and the third insulating films,
• wherein the fourth insulating film blocks the first opening,
• wherein a second cavity is formed between the first insulating film and the second insulating film, on a first region other than the sensor region on the main surface of the semiconductor device,
• wherein a second opening is formed in the second and the third insulating films to reach the second cavity by penetrating through the second and the third insulating films,
• wherein the fourth insulating film blocks the second opening, and
• wherein among the second cavities, no second conducting layer is formed below the second cavity position farthest from the second opening.