Infrared sensor

Abstract

An infrared sensor is formed in such a manner that an infrared receiver and a base substrate are spaced with a beam made of a thin-film phononic crystal in which through holes are arranged periodically. The beam made of a phononic crystal is formed in such a manner that a period P of through holes increases at arbitrary intervals in a direction from the infrared receiver toward the base substrate.

What is claimed is: 
     
         1 . An infrared sensor comprising:
 a base substrate comprising a recess portion;   a thermopile infrared receiver;   a first beam; and   a second beam, wherein:   one end of the first beam is connected to the infrared receiver,   other end of the first beam is connected to the base substrate,   one end of the second beam is connected to the infrared receiver,   other end of the second beam is connected to the base substrate,   the recess portion is located between the infrared receiver and the base substrate in a cross-sectional view in such a manner that the infrared receiver is suspended above the base substrate,   the recess portion is located between the first beam and the base substrate in a cross-sectional view in such a manner that the first beam is suspended above the base substrate,   the recess portion is located between the second beam and the base substrate in a cross-sectional view in such a manner that the second beam is suspended above the base substrate,   the first beam consists only of a p-type first domain and a p-type second domain,   the p-type first domain is located between the p-type second domain and the infrared receiver in a plan view,   the p-type first domain is formed of a phononic crystal comprising through holes arranged regularly at a period p1 p ,   the p-type second domain is formed of a phononic crystal comprising through holes arranged regularly at a period p2 p ,   a value of the period p2 p  is greater than a value of the period p1 p ,   the second beam consists only of an n-type first domain and an n-type second domain,   the n-type first domain is located between the n-type second domain and the infrared receiver in a plan view,   the n-type first domain is formed of a phononic crystal comprising through holes arranged regularly at a period p1 n ,   the n-type second domain is formed of a phononic crystal comprising through holes arranged regularly at a period p2 n , and   a value of the period p2 n  is greater than a value of the period p1 n .   
     
     
         2 . The infrared sensor according to  claim 1 , further comprising:
 a first electric wire electrically connected to the first beam;   a second electric wire electrically connected to the second beam;   a first electrode electrically connected to the first electric wire; and   a second electrode electrically connected to the second electric wire.