Current-perpendicular-to-plane magnetoresistance effect device with double current control layers

Abstract

A magnetoresistance effect element of the dual spin valve type using a current-perpendicular-to-the-plane (CPP) system where a sensing current flows perpendicular to the stacked faces of a plurality of conductive layers, the magnetoresistance effect element comprises a first unit which includes a free layer and a first pinning layer, a second unit which includes the free layer shared with the first unit and a second pinning layer, a first current control layer which is provided in the first unit and limits the flow quantity of the sensing current, and a second current control layer which is provided in the second unit and limits the flow quantity of the sensing current.

1 . A magnetoresistance effect element of the dual spin valve type using a current-perpendicular-to-the-plane (CPP) system where a sensing current flows perpendicular to the stacked faces of a plurality of conductive layers, the magnetoresistance effect element comprising: 
 a first unit which includes a free layer; and    a second unit which includes the free layer shared with the first unit; wherein    the first unit includes: 
 a first nonmagnetic intermediate layer;  
 a second nonmagnetic intermediate layer; and  
 a first current control layer which limits the flow quantity of the sensing current and is sandwiched between the first and second nonmagnetic intermediate layers;  
   the second unit includes: 
 an upper pinning layer;  
 an upper antiferromagnetic layer which pins the direction of magnetization of the upper pinning layer; and  
 a second current control layer which limits the flow quantity of the sensing current and is sandwiched between the upper pinning layer and the upper antiferromagnetic layer;  
   the first current control layer comprises: 
 an insulating material which insulates the first and second nonmagnetic intermediate layers from one another electrically, and  
 a conductive material which is formed in the insulating material in a distributed manner and which connects the first and second nonmagnetic intermediate layers to each other electrically so as to permit the sensing current to pass through the insulating material in a confining fashion;  
   the second current control layer comprises: 
 an insulating material which insulates the upper pinning layer and the upper antiferromagnetic layer from one another electrically, and  
 a conductive material which is formed in the insulating material in a distributed manner and which connects the upper pinning layer and the upper antiferromagnetic layer to each other electrically so as to permit the sensing current to pass through the insulating material in a confining fashion.  
   
     
     
         2 . The magnetoresistance effect element according to  claim 1 , wherein the first unit includes a lower pinning layer.  
     
     
         3 . The magnetoresistance effect element according to  claim 2 , wherein the first unit includes 
 a lower antiferromagnetic layer which pins the direction of magnetization of the lower pinning layer.    
     
     
         4 . The magnetoresistance effect element according to  claim 1 , wherein the film thickness of the insulating materials is 0.4 nanometers or more and 3 nanometers or less.  
     
     
         5 . The magnetoresistance effect element according to  claim 1 , which is a giant magnetoresistance (GMR) effect element.