Infrared sensor

A method for manufacturing an infrared sensor comprising:

• a step of forming an active element in a semiconductor substrate;
• a step of forming an interlayer insulating film on the semiconductor substrate
• a step of forming a contact so as to penetrate through the interlayer insulating film in a thickness direction thereof and so as to be electrically connected to the active element;
• a step of forming a thin-film pyroelectric element made of lead titanate zirconate on the interlayer insulating film by a sol-gel method;
• a step of coating the pyroelectric element with a coating film on the interlayer insulating film, after forming of the pyroelectric element;
• and
• a step of forming wirings, so as to be electrically connected to the active element and the pyroelectric element, respectively, on the coating film.

A sensor device comprising:

• a silicon substrate;
• a transistor formed on the silicon substrate;
• a pyroelectric element disposed on the silicon substrate;
• a cavity formed below the pyroelectric element in the silicon substrate.

A sensor device comprising:

• a silicon substrate;
• a transistor formed on the silicon substrate;
• a pyroelectric element disposed on the silicon substrate;
• a thermocouple disposed on the silicon substrate.