Method for manufacturing an infrared detection element

Abstract

The present invention provides an infrared detection element having a single-crystalline base layer 3 with a thickness of 50 nm to 10 μm having a principal surface, a first electrode layer 4 formed on the principal surface of the single-crystalline base layer 3 , a ferroelectric layer 5 which is formed on the first electrode layer 4 and is composed of a single-crystalline layer or a unidirectioally oriented layer. Distortion of the single-crystalline layer or a unidirectioally oriented layer in a surface parallel to the principal surface of the single-crystalline base layer 3 is elastically constrained by the single-crystalline base layer 3 . The infrared detection element further has a second electrode layer 6 formed on the ferroelectric layer 5 . An amount of charge is changed by changes in temperature caused by irradiation of infrared light to the ferroelectric layer 5 . The amount of the charge is detected from the first and the second electrode layer 4, 6 . With the infrared detection element, an accurate temperature measurement is possible even in the neighborhood of the Curie temperature due to a discontinuous primary phase transition.

1 . A method for manufacturing an infrared detection element comprising steps of: 
 providing a single-crystalline base layer with a thickness of 50 nm to 10 μm having a principal surface,    forming a first electrode layer on a principal surface of the single-crystalline layer,    forming a single-crystalline or a unidirectioally oriented ferroelectric layer on the first electrode layer, so that a distortion of which is elastically constrained by the single-crystalline base layer in a plain parallel to the principal surface of the single-crystalline base layer, and    forming a second electrode layer on the ferroelectric layer.    
   
   
       2 . A method for manufacturing an infrared detection element according to  claim 1 , wherein the ferroelectric layer has a perovskite structure.  
   
   
       3 . A method for manufacturing an infrared detection element according to  claim 1 , wherein the ferroelectric layer has a main component of Ba 1-x Sr x TiO 3  (0≦×≦1).  
   
   
       4 . A method for manufacturing an infrared detection element according to  claim 1 , wherein the first electrode layer is made of a noble metal layer or of a conductive oxide layer having a perovskite structure and a thickness of 1 μm or less.  
   
   
       5 . A method for manufacturing an infrared detection element according to  claim 2 , wherein the single-crystalline base layer has a surface oriented to (001) direction and the ferroelectric layer is epitaxially grown or is orientatedly grown in the (001) direction.  
   
   
       6 . A method for manufacturing an infrared detection element according to  claim 2 , wherein “a” “b” axes of the ferroelectric layer are formed in a plain parallel to the principal surface of the semiconductor layer and “c” axis of the ferroelectric layer is formed in a direction perpendicular to the principal surface of the semiconductor layer.  
   
   
       7 . A method for manufacturing an infrared detection element comprising steps of: 
 forming a silicon single-crystalline base layer with a thickness of 50 nm to 10 μm having a principal surface,    forming a first electrode layer on a principal surface of the single-crystalline layer,    forming a single-crystalline ferroelectric layer by an epitaxial growth or an unidirectioally oriented ferroelectric layer by orientation growth on the principal surface of the single-crystalline base layer, and    forming a second electrode layer formed on the ferroelectric layer.    
   
   
       8 . A method for manufacturing an infrared detection element according to  claim 7 , wherein the ferroelectric layer has a perovskite structure.  
   
   
       9 . A method for manufacturing an infrared detection element according to  claim 8 , wherein the ferroelectric layer has a main component of Ba 1-x Sr x TiO 3  (0≦×≦1).  
   
   
       10 . A method for manufacturing an infrared detection element according to  claim 1 , wherein the first electrode layer is made of a noble metal layer or a conductive oxide layer having a perovskite structure and a thickness of 1 μm or less.  
   
   
       11 . A method for manufacturing an infrared detection element comprising steps of: 
 forming a single-crystalline base layer with a thickness of 50 nm to 10 μm having a principal surface,    forming a first electrode layer on the principal surface of the single-crystalline layer,    forming a first ferroelectric layer on the first electrode layer, which is composed of a single-crystalline layer or a unidirectioally oriented layer, and a distortion of which is elastically constrained by the single-crystalline base layer in a plain parallel to the principal surface of the single-crystalline base layer,    forming an infrared detection element having a second electrode layer on the ferroelectric layer,    forming a third electrode layer on the principal surface of the single-crystalline base layer,    forming a second ferroelectric layer on the first electrode layer, which is composed of a first single-crystalline layer or a unidirectioally oriented layer, and a distortion of which is elastically constrained by the single-crystalline base layer in a plain parallel to the principal surface of the single-crystalline base layer,    forming a reference cell having a fourth electrode layer on the ferroelectric layer, and    forming an infrared reflection film on the reference cell.    
   
   
       12 . A method for manufacturing an infrared detection element according to  claim 11 , wherein the first and second ferroelectric layers have a perovskite structure.  
   
   
       13 . A method for manufacturing an infrared detection element according to  claim 12 , wherein the first and second ferroelectric layers have a main component of Ba 1-x Sr x TiO 3  (0≦×≦1).  
   
   
       14 . A method for manufacturing an infrared detection element according to  claim 13 , wherein the first and third electrode layers are made of a noble metal layer or a conductive oxide layer having a perovskite structure.  
   
   
       15 . A method for manufacturing an infrared detection element according to  claim 14 , wherein the single-crystalline layer is a single-crystalline silicon layer having a surface oriented to (001) direction and the first and second ferroelectric layers are epitaxially grown or are orientationally grown in the (001) direction.  
   
   
       16 . A method for manufacturing an infrared detection element according to  claim 15 , wherein “a” and “b” axes of the ferroelectric layer are formed in the plain parallel to the principal surface of the semiconductor layer and “c” axis of the-ferroelectric layer is formed in a direction perpendicular to the principal surface of the semiconductor layer.  
   
   
       17 . A method for manufacturing an infrared detection element comprising steps of: 
 forming a single-crystalline base layer with a thickness of 50 nm to 10 μm having a principal surface,    forming a first electrode layer on the principal surface of the single-crystalline layer,    forming a first ferroelectric layer composed of a single-crystalline layer fixedly on the first electrode layer,    forming an infrared detection element having a second electrode layer on the ferroelectric layer,    forming a third electrode layer on the principal surface of the single-crystalline base layer,    forming a second ferroelectric layer composed of    a single-crystalline layer fixedly on the third electrode layer,    forming a reference cell having a fourth electrode layer on the ferroelectric layer, and    forming an infrared reflection film formed on the reference cell.