Magnetoresistance Effect Element, Method of Manufacturing Same and Magnetic Head Utilizing Same

Abstract

A magnetoresistance effect element is manufactured in the steps in which a first ferromagnetic layer is formed on a substrate, the first ferromagnetic layer is patterned to form a pinned layer, in shape of strip, having both end portions to which electrode pads are formed, the pinned layer is etched, for example, through ion milling, so as to form at least one nano-contact portion, an insulating layer is formed by embedding an insulating material into the etched pinned layer around the nano-contact portion, a second ferromagnetic layer is formed so as to contact at least the nano-contact portion, and this second ferromagnetic layer is patterned to form a free layer, in shape of strip, having both end portions to which electrode pads are formed.

1 - 21 . (canceled)  
   
   
       22 . A method of manufacturing a magnetoresistance effect element comprising the steps of: 
 preparing a substrate;    forming a first ferromagnetic layer on the substrate;    patterning the first ferromagnetic layer so as to form a pinned layer, in the shape of a strip, having both end portions to which electrode pads are formed;    etching the pinned layer in two steps with different angles so as to form at least one nano-contact portion;    embedding an insulating material to the etched pinned layer so as to form an insulating layer around the nano-contact portion;    forming a second ferromagnetic layer so as to contact at least the nano-contact portion; and    patterning the second ferromagnetic layer so as to form a free layer, in shape of strip, having both end portions to which electrode pads are formed.    
   
   
       23 . A method of manufacturing a magnetoresistance effect element according to  claim 22 , wherein an anti-ferromagnetic layer is formed on the substrate before the formation of the first ferromagnetic layer.  
   
   
       24 . A method of manufacturing a magnetoresistance effect element according to  claim 22 , wherein said first ferromagnetic layer forming step including a formation of either one of cases of forming a single ferromagnetic layer and forming two ferromagnetic layers between which a non-magnetic layer is further formed.  
   
   
       25 . A method of manufacturing a magnetoresistance effect element according to  claim 22 , wherein said etching step to the pinned layer to form the nano-contact portion is effected by ion milling so that the maximum dimension of the nano-contact portion is not more than mean free path.  
   
   
       26 . A method of manufacturing a magnetoresistance effect element according to  claim 25 , wherein said ion milling process is carried out twice from directions different from each other.  
   
   
       27 . A method of manufacturing a magnetoresistance effect element according to  claim 22 , wherein a plurality of pinned layers, each in the shape of a strip, provided at both end thereof with the electrode pads, are formed on the substrate in the patterning step for forming the pinned layer.  
   
   
       28 . A method of manufacturing a magnetoresistance effect element according to  claim 22 , wherein said second ferromagnetic layer forming step including a formation of either one of cases of forming a single ferromagnetic layer and forming two ferromagnetic layers between which a non-magnetic layer is further formed.  
   
   
       29 . A method of manufacturing a magnetoresistance effect element according to  claim 22 , further comprising the step of forming external electrodes on the electrode pads, respectively.  
   
   
       30 . A method of manufacturing a magnetoresistance effect element according to  claim 22 , wherein the ferromagnetic layers of the pinned layer and the free layer, as well as the nano-contact portion, are each formed of a material selected from the groups consisting of a ferromagnetic metal group of Co, Fe, Ni, CoFe, NiFe, CoFeNi; a ferromagnetic metalloid group of CrO 2 ; and a ferromagnetic oxide of Fe 3 O 4 .