Tunnel magnetoresistive element, thin-film magnetic head and memory element, and methods of manufacturing same

Abstract

A TMR element includes: a free layer formed on a lower gap layer; a tunnel barrier layer formed on the free layer; and a pinned layer formed on the tunnel barrier layer. The pinned layer and the tunnel barrier layer have sidewalls formed through etching. The TMR element further comprises a deposition layer made of a material that is separated by etching and deposits on the sidewalls and undergoes oxidation.

What is claimed is:  
     
         1 . A tunnel magnetoresistive element comprising a tunnel barrier layer and two magnetic layers sandwiching the tunnel barrier layer, wherein: 
 the tunnel barrier layer and at least one of the magnetic layers include sidewalls formed through etching; and    the tunnel magnetoresistive element further comprises a deposition layer made of a material that is separated through the etching and deposits on the sidewalls and undergoes oxidation or nitriding.    
     
     
         2 . A thin-film magnetic head incorporating a tunnel magnetoresistive element comprising a tunnel barrier layer and two magnetic layers sandwiching the tunnel barrier layer, wherein: 
 the tunnel barrier layer and at least one of the magnetic layers include sidewalls formed through etching; and    the tunnel magnetoresistive element further comprises a deposition layer made of a material that is separated through the etching and deposits on the sidewalls and undergoes oxidation or nitriding.    
     
     
         3 . A memory element incorporating a tunnel magnetoresistive element comprising a tunnel barrier layer and two magnetic layers sandwiching the tunnel barrier layer, wherein: 
 the tunnel barrier layer and at least one of the magnetic layers include sidewalls formed through etching; and    the tunnel magnetoresistive element further comprises a deposition layer made of a material that is separated through the etching and deposits on the sidewalls and undergoes oxidation or nitriding.    
     
     
         4 . A method of manufacturing a tunnel magnetoresistive element comprising a tunnel barrier layer and first and second magnetic layers sandwiching the tunnel barrier layer, the method including the steps of: 
 forming the first magnetic layer;    forming the tunnel barrier layer on the first magnetic layer;    forming the second magnetic layer on the tunnel barrier layer;    forming sidewalls of at least the second magnetic layer and the tunnel barrier layer by selectively etching these layers; and    performing processing for increasing a resistance value of a deposition layer made of a material that is separated through the etching and deposits on the sidewalls.    
     
     
         5 . The method according to    claim 4    wherein the processing for increasing the resistance value of the deposition layer is oxidation or nitriding of the deposition layer.  
     
     
         6 . A method of manufacturing a thin-film magnetic head incorporating a tunnel magnetoresistive element comprising a tunnel barrier layer and first and second magnetic layers sandwiching the tunnel barrier layer, the method including the steps of: 
 forming the first magnetic layer;    forming the tunnel barrier layer on the first magnetic layer;    forming the second magnetic layer on the tunnel barrier layer;    forming sidewalls of at least the second magnetic layer and the tunnel barrier layer by selectively etching these layers; and    performing processing for increasing a resistance value of a deposition layer made of a material that is separated through the etching and deposits on the sidewalls.    
     
     
         7 . The method according to    claim 6    wherein the processing for increasing the resistance value of the deposition layer is oxidation or nitriding of the deposition layer.  
     
     
         8 . A method of manufacturing a memory element incorporating a tunnel magnetoresistive element comprising a tunnel barrier layer and first and second magnetic layers sandwiching the tunnel barrier layer, the method including the steps of forming the first magnetic layer; 
 forming the tunnel barrier layer on the first magnetic layer;    forming the second magnetic layer on the tunnel barrier layer;    forming sidewalls of at least the second magnetic layer and the tunnel barrier layer by selectively etching these layers; and    performing processing for increasing a resistance value of a deposition layer made of a material that is separated through the etching and deposits on the sidewalls.    
     
     
         9 . The method according to    claim 8    wherein the processing for increasing the resistance value of the deposition layer is oxidation or nitriding of the deposition layer.