INFRARED SENSOR AND CARBON DIOXIDE SENSOR

PROBLEM TO BE SOLVED: To selectively detect infrared light having a specific wavelength in a simple structure in an infrared sensor for detecting infrared light having a specific wavelength and to provide a carbon dioxide sensor using the infrared sensor. SOLUTION: This infrared sensor 10 is constituted by a silicon substrate 1 and a thermopile 2 formed on one side face of the silicon substrate 1. The thermopile 2 includes a plane portion 21 at a silicon substrate 1 side and a structure body layer 11 is formed on a part of the silicon substrate 1 contacting the plane portion 21. The structure body layer 11 is so constituted that a recessed portion 11a concaved to a plane portion 21 side of the thermopile 2 and a projected portion 11b convexed to the opposite side of the plane portion 21 are alternately formed. Namely, the recessed portion 11a and the projected portion 11b are formed such that a groove and a rib are alternately arranged and a cross-sectional shape of the recessed portion 11a and the projected portion 11b is formed to be like a rectangular wave. A length of one cycle of one set of the recessed portion 11a and the projected portion 11b is made to be a wavelength of the specific infrared radiation. This carbon dioxide sensor is so constituted that the infrared sensor 10 in which the one cycle of the recessed portion 11a and the projected portion 11b is made to be 4.3 μm and an infrared radiation source are accommodated in a case having a window section. COPYRIGHT: (C)2010,JPO&INPIT