Magnetoresistive element and method for producing the same, as well as magnetic head, magnetic memory and magnetic recording device using the same

Abstract

The present invention provides a method for producing a magnetoresistive element including a tunnel insulating layer, and a first magnetic layer and a second magnetic layer that are laminated so as to sandwich the tunnel insulating layer, wherein a resistance value varies depending on a relative angle between magnetization directions of the first magnetic layer and the second magnetic layer. The method includes the steps of: (i) laminating a first magnetic layer, a third magnetic layer and an Al layer successively on a substrate; (ii) forming a tunnel insulating layer containing at least one compound selected from the group consisting of an oxide, nitride and oxynitride of Al by performing at least one reaction selected from the group consisting of oxidation, nitriding and oxynitriding of the Al layer; and (iii) forming a laminate including the first magnetic layer, the tunnel insulating layer and a second magnetic layer by laminating the second magnetic layer in such a manner that the tunnel insulating layer is sandwiched by the first magnetic layer and the second magnetic layer. The third magnetic layer has at least one crystal structure selected from the group consisting of a face-centered cubic crystal structure and a face-centered tetragonal crystal structure and is (111) oriented parallel to a film plane of the third magnetic layer. According to this production method, it is possible to produce a magnetoresistive element with excellent properties and thermal stability.

1 - 8 . (Canceled)  
     
     
         9 . A magnetoresistive element comprising: a tunnel insulating layer containing at least one compound selected from the group consisting of an oxide, nitride and oxynitride of Al; a first magnetic layer and a second magnetic layer that are laminated so as to sandwich the tunnel insulating layer; and a third magnetic layer disposed between the first magnetic layer and the tunnel insulating layer, 
 wherein a resistance value varies depending on a relative angle between magnetization directions of the first magnetic layer and the second magnetic layer, and    the third magnetic layer has at least one crystal structure selected from the group consisting of a face-centered cubic crystal structure and a face-centered tetragonal crystal structure and is (111) oriented parallel to a film plane of the third magnetic layer.    
     
     
         10 . The magnetoresistive element according to  claim 9 , 
 wherein the third magnetic layer comprises a magnetic material containing at least one element selected from the group consisting of Fe, Co and Ni.    
     
     
         11 . The magnetoresistive element according to  claim 10 , 
 wherein the magnetic material has a composition represented by the formula Fe x Co y ,    where x and y are values satisfying the following equations:     x+y =10.05 ≦x≦ 0.30.7 ≦y≦ 0.95   
     
     
         12 . The magnetoresistive element according to  claim 10 , 
 wherein the magnetic material has a composition represented by the formula Fe x′ Ni y′ ,    where x′ and y′ are values satisfying the following equations:     x′+y ′=10≦x′≦0.70.3≦y′≦1.   
     
     
         13 . The magnetoresistive element according to  claim 10 , 
 wherein the magnetic material further contains at least one element selected from the group consisting of Rh, Pd, Ag, Ir, Pt and Au.    
     
     
         14 . The magnetoresistive element according to  claim 13 , 
 wherein the magnetic material has a composition represented by the formula M p Z q ,    where M is at least one element selected from the group consisting of Fe, Co and Ni,    Z is at least one element selected from the group consisting of Rh, Pd, Ag, Ir, Pt and Au, and    p and q are values satisfying the following equations:     p+q =1 0.6 ≦p≦0.990.01≦q≦0.4.   
     
     
         15 . The magnetoresistive element according to  claim 9 , further comprising an antiferromagnetic layer.  
     
     
         16 . The magnetoresistive element according to  claim 15 , 
 wherein the antiferromagnetic layer is disposed on a side opposite a plane of the first magnetic layer facing the tunnel insulating layer and is (111) oriented parallel to a film plane of the antiferromagnetic layer.    
     
     
         17 . A magnetic head comprising the magnetoresistive element according to  claim 9  and a shield for limiting an introduction of a magnetic field other than a magnetic field to be detected by the magnetoresistive element to the magnetoresistive element.  
     
     
         18 . A magnetic head comprising the magnetoresistive element according to  claim 9  and a magnetic flux guiding portion for guiding a magnetic field to be detected by the magnetoresistive element to the magnetoresistive element.  
     
     
         19 . A magnetic memory comprising the magnetoresistive element according to  claim 9 , an information recording conductive line for recording information on the magnetoresistive element and an information reading conductive line for reading the information.  
     
     
         20 . The magnetic memory according to  claim 19 , 
 wherein a plurality of the magnetoresistive elements are disposed in the form of a matrix.    
     
     
         21 . A magnetic recording device comprising the magnetic head according to  claim 17  and a magnetic recording medium capable of reading magnetic information with the magnetic head.  
     
     
         22 . A magnetic recording device comprising the magnetic head according to  claim 18  and a magnetic recording medium capable of reading magnetic information with the magnetic head.