Patent ID: 8039798

Claim:
A dual-wavelength thermal infrared sensor that has a thermal insulation structure and comprises a plurality of pixels that detect incident infrared rays, wherein the plurality of pixels include pixels of a first type and pixels of a second type that detect infrared rays in different wavelength ranges, the pixel of the first type and the pixel of the second type each include a diaphragm that is supported by beams extending from a substrate to have a gap from the substrate; an eave that is formed to spread outward from the diaphragm; and a reflection film that substantially reflects infrared rays and exists on the substrate immediately beneath the diaphragm, the diaphragm includes: a thermoelectric conversion material thin film that is substantially transmissive to infrared rays; an electrode that catches a change of a physicality of the thermoelectric conversion material thin film; and protective films that enclose the thermoelectric conversion material thin film and the electrode, and the protective films of the diaphragm and the eave are made of a material that has a relatively large absorption coefficient for infrared rays in a first wavelength range and a relatively small absorption coefficient for infrared rays in a second wavelength range different from the first wavelength range, the pixel of the first type further includes metal thin films that are formed on an upper surface of the diaphragm and an upper surface of the eave respectively; the pixel of the first type has sensitivity to infrared rays in the first wavelength range that are absorbed by the protective films and the eave, and to infrared rays in the second wavelength range that is defined by an optical interference that occurs between the metal thin films and the reflection film, and the pixel of the second type has sensitivity to infrared rays in the first wavelength range that are absorbed by the protective films and the eave.