Patent ID: 8426864

Claim:
An infrared sensor comprising: a base; and an infrared detection element formed over a surface of said base, wherein said infrared detection element comprises: an infrared absorption member in the form of a thin film configured to absorb infrared, and spaced from the surface of said base for thermal insulation; and a temperature detection member configured to measure a temperature difference between said infrared absorption member and said base, and including a thermocouple, said thermocouple including a p-type polysilicon layer, an n-type polysilicon layer, and a connection layer, said p-type polysilicon layer formed over said infrared absorption member and said base, said n-type polysilicon layer formed over said infrared absorption member and said base without contact with said p-type polysilicon layer, and said connection layer being configured to electrically connect said p-type polysilicon layer to said n-type polysilicon layer, each of said p-type polysilicon layer and said n-type polysilicon layer having an impurity concentration in a range of 10 18 to 10 20 cm −3 , said p-type polysilicon layer having its thickness of λ/4n 1p , wherein λ denotes a center wavelength of the infrared to be detected by said infrared detection element, and n 1p denotes a reflective index of said p-type polysilicon layer, and said n-type polysilicon layer having its thickness of λ/4n 1n , wherein n 1n denotes a reflective index of said n-type polysilicon layer.