Current-perpendicular-to-plane magnetoresistance effect device with double current double 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: 
 an lower pinning layer;  
 a first current control layer which limits the flow quantity of the sensing current and is sandwiched between the free layer and the lower pinning layer;  
   the second unit includes: 
 a upper pinning layer;  
 a second current control layer which limits the flow quantity of the sensing current and is sandwiched between the free layer and the upper pinning layer;  
   the first current control layer comprises: 
 an insulating material which insulates the free layer and the lower pinning layer from one another electrically, and  
 a conductive material which is formed in the insulating material in a distributed manner and which connects the free layer and the lower pinning layer 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 free layer and the upper pinning layer from one another electrically, and  
 a conductive material which is formed in the insulating material in a distributed manner and which connects the free layer and the upper pinning 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 insulating material is nonmagnetic material.  
     
     
         3 . 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.  
     
     
         4 . The magnetoresistance effect element according to  claim 1 , which is a giant magnetoresistance (GMR) effect element.