Strain detection element, pressure sensor, microphone, blood pressure sensor, and touch panel

Abstract

A strain detection element is provided above a deformable membrane. Moreover, this strain detection element includes an electrode and a stacked body, the stacked body including: a first magnetic layer whose magnetization direction is variable according to a deformation of the membrane; a second magnetic layer provided facing the first magnetic layer; and an intermediate layer provided between these first magnetic layer and second magnetic layer, and at least part of the first magnetic layer is amorphous, and the electrode includes a metal layer configured from a Cu—Ag alloy.

1 .- 19 . (canceled) 
     
     
         20 . A strain detection element configured to be fixed to a membrane being deformable, the strain detection element comprising:
 a metal layer including;   a first magnetic layer;   a second magnetic layer provided between the metal layer and the first magnetic layer; and   an intermediate layer provided between the first magnetic layer and the second magnetic layer,   an electrical resistance of the strain detection element being configured to change in accordance with a strain of the membrane,   the metal layer including a first face on a side of the second magnetic layer,   the intermediate layer including a second face on a side of the first magnetic layer, and   the second face being flatter than the first face.   
     
     
         21 . The strain detection element according to  claim 20 , wherein the metal layer includes at least one selected from the group consisting of Cu, Al, Au, Ag, Ni, Fe, and Co. 
     
     
         22 . The strain detection element according to  claim 20 , wherein the metal layer includes Cu and Ag. 
     
     
         23 . The strain detection element according to  claim 20 , wherein the metal layer includes a Cu 1-x Ag x  alloy (1 at. %≤x≤20 at. %). 
     
     
         24 . The strain detection element according to  claim 20 , wherein the first magnetic layer includes boron. 
     
     
         25 . The strain detection element according to  claim 24 , wherein
 the first magnetic layer includes a first portion and a second portion,   the first portion is located between the intermediate layer and the second portion, and   a concentration of boron in the first portion is lower than a concentration of boron in the second portion.   
     
     
         26 . The strain detection element according to  claim 20 , wherein
 the first magnetic layer includes a first portion and a second portion,   the first portion is located between the intermediate layer and the second portion,   at least part of the first portion is crystalline, and   at least part of the second portion is amorphous.   
     
     
         27 . The strain detection element according to  claim 20 , wherein the intermediate layer includes at least one selected from the group consisting of an oxide and a nitride. 
     
     
         28 . The strain detection element according to  claim 20 , further comprising:
 a first layer provided between the metal layer and the first magnetic layer, the first layer including at least one selected from Ta, Ti, and TiN,   the second magnetic layer being provided between the first layer and the first magnetic layer,   the metal layer having a third face opposing the first layer,   the first layer having a fourth face opposing the second magnetic layer, and   the third face being rougher than the fourth face.   
     
     
         29 . The strain detection element according to  claim 28 , wherein at least part of the first magnetic layer is amorphous. 
     
     
         30 . A pressure sensor, comprising:
 the membrane being deformable;   a supporting part supporting the membrane; and   the strain detection element according to  claim 20 , the strain detection element being fixed to the membrane.   
     
     
         31 . A microphone, comprising:
 the pressure sensor according to  claim 30 .   
     
     
         32 . A strain detection element configured to be fixed to a membrane being deformable, the strain detection element comprising:
 a metal layer including;   a first magnetic layer;   a second magnetic layer provided between the metal layer and the first magnetic layer; and   an intermediate layer provided between the first magnetic layer and the second magnetic layer,   an electrical resistance of the strain detection element being configured to change in accordance with a strain of the membrane,   the metal layer having a first grain size,   the second magnetic layer having a second grain size smaller than the first grain size.   
     
     
         33 . The strain detection element according to  claim 32 , wherein the metal layer includes at least one selected from the group consisting of Cu, Al, Au, Ag, Ni, Fe, and Co. 
     
     
         34 . The strain detection element according to  claim 32 , wherein the metal layer includes Cu and Ag. 
     
     
         35 . The strain detection element according to  claim 32 , wherein the metal layer includes a Cu 1-x Ag x  alloy (1 at. %≤x≤20 at. %). 
     
     
         36 . The strain detection element according to  claim 32 , further comprising:
 a first layer provided between the metal layer and the first magnetic layer, the first layer including at least one selected from Ta, Ti, and TiN,   the second magnetic layer being provided between the first layer and the first magnetic layer,   the metal layer having a third face opposing the first layer,   the first layer having a fourth face opposing the second magnetic layer, and   the third face being rougher than the fourth face.   
     
     
         37 . The strain detection element according to  claim 36 , wherein at least part of the first magnetic layer is amorphous.