Magnetoresistive element and method of manufacturing the same

Abstract

A magnetoresistive element includes a magnetoresistive film including a magnetization pinned layer, a magnetization free layer, an intermediate layer arranged between the magnetization pinned layer and the magnetization free layer, a cap layer arranged on the magnetization pinned layer or on the magnetization free layer, and a functional layer arranged in the magnetization pinned layer, in the magnetization free layer, in the interface between the magnetization pinned layer and the intermediate layer, in the interface between the intermediate layer and the magnetization free layer, or in the interface between the magnetization pinned layer or the magnetization free layer and the cap layer, and a pair of electrodes which pass a current perpendicularly to a plane of the magnetoresistive film, in which the functional layer is formed of a layer including nitrogen and a metal material containing 5 atomic % or more of Fe.

1 . A magnetoresistive element comprising:
 a magnetoresistive film comprising a magnetization pinned layer a magnetization direction of which is substantially pinned in one direction, a magnetization free layer a magnetization direction of which is varied depending on an external magnetic field, an intermediate layer arranged between the magnetization pinned layer and the magnetization free layer, a cap layer arranged on the magnetization pinned layer or on the magnetization free layer, and a functional layer arranged in the magnetization pinned layer, in the magnetization free layer, in the interface between the magnetization pinned layer and the intermediate layer, in the interface between the intermediate layer and the magnetization free layer, or in the interface between the magnetization pinned layer or the magnetization free layer and the cap layer; and   a pair of electrodes which pass a current perpendicularly to a plane of the magnetoresistive film,   the functional layer being formed of a layer comprising nitrogen and a metal material containing 5 atomic % or more of Fe.   
     
     
         2 . The magnetoresistive element according to  claim 1 , wherein the functional layer has a crystalline orientation dispersion angle of 5 degrees or less. 
     
     
         3 . The magnetoresistive element according to  claim 1 , wherein the magnetization pinned layer or the magnetization free layer has a crystalline orientation dispersion angle of 5 degrees or less. 
     
     
         4 . The magnetoresistive element according to  claim 1 , wherein the functional layer is formed of an alloy including Fe and Co. 
     
     
         5 . The magnetoresistive element according to  claim 1 , wherein the functional layer has a thickness from 0.3 nm to 5 nm. 
     
     
         6 . The magnetoresistive element according to  claim 1 , wherein the functional layer has a Fe content of 50 atomic % or more. 
     
     
         7 . The magnetoresistive element according to  claim 1 , wherein the intermediate layer is a metal layer comprising an element selected from the group consisting of Au, Ag and Cu. 
     
     
         8 . The magnetoresistive element according to  claim 1 , wherein the intermediate layer comprises an insulating layer containing nitrogen or oxygen and a current path penetrating the insulating layer. 
     
     
         9 . The magnetoresistive element according to  claim 8 , wherein the current path comprises an element selected from the group consisting of Au, Ag, Cu, Fe, Co and Ni. 
     
     
         10 . The magnetoresistive element according to  claim 8 , wherein the current path has a diameter of 1 nm or more and 7 nm or less. 
     
     
         11 . A magnetoresistive element comprising:
 a magnetoresistive film comprising a first magnetization free layer a magnetization direction of which is varied depending on an external magnetic field, a second magnetization free layer a magnetization direction of which is varied depending on an external magnetic field, an intermediate layer arranged between the first magnetization free layer and the second magnetization free layer, and a functional layer arranged in the first magnetization free layer, in the second magnetization free layer, in the interface between the first magnetization free layer and the intermediate layer, in the interface between the intermediate layer and the second magnetization free layer, or in the interface of the second magnetization free layer opposite to the interface that is in contact with the intermediate layer; and   a pair of electrodes which pass a current perpendicularly to a plane of the magnetoresistive film,   the functional layer being formed of a layer comprising nitrogen and a metal material containing 5 atomic % or more of Fe.   
     
     
         12 . The magnetoresistive element according to  claim 11 , wherein the functional layer has a crystalline orientation dispersion angle of 5 degrees or less. 
     
     
         13 . The magnetoresistive element according to  claim 11 , wherein the intermediate layer is a metal layer comprising an element selected from the group consisting of Au, Ag and Cu. 
     
     
         14 . The magnetoresistive element according to  claim 11 , wherein the intermediate layer comprises an insulating layer containing nitrogen or oxygen and a current path penetrating the insulating layer. 
     
     
         15 . A magnetic head gimbal assembly comprising the magnetoresistive element of  claim 1 . 
     
     
         16 . A magnetic recording apparatus comprising the magnetic head gimbal assembly of  claim 15 . 
     
     
         17 . A method of manufacturing a magnetoresistive element comprising a magnetoresistive film including a functional layer arranged in a magnetization pinned layer, in a magnetization free layer, in an interface between the magnetization pinned layer and an intermediate layer, in an interface between the intermediate layer and the magnetization free layer, or in an interface between the magnetization pinned layer or the magnetization free layer and a cap layer, the method comprising:
 depositing a metal layer containing 5 atomic % or more of Fe and exposing the metal layer to a nitrogen atmosphere to form the functional layer; and   repeating the depositing step two or more times.   
     
     
         18 . The method according to  claim 17 , wherein a thickness of the functional layer in T nanometers and a number of times N, by which the modules are repeated, satisfies the following formula:
     N ≧( T/ 0.5)× x,      
       where x is a constant of 1 to 2, and T≧1. 
     
     
         19 . The method according to  claim 17 , wherein a thickness of the metal layer deposited in one module is 1 nm or less.