Magneto-resistive device and method of manufacturing same, magnetic head, head suspension assembly and magnetic disk apparatus

Abstract

A magneto-resistive device is provided for reducing the deterioration in the characteristics of the device due to annealing. The magneto-resistive device has a magneto-resistive layer formed on one surface side of a base, and an insulating layer formed of two layers and deposited around the magneto-resistive layer. The layer of the insulating layer closest to the base is made of a metal or semiconductor oxide. This layer extends over end faces of a plurality of layers made of different materials from one another, which make up the magneto-resistive device, and is in contact with the end faces of the plurality of layers with the same materials.

What is claimed is:  
     
         1 . A magneto-resistive device comprising: 
 a magneto-resistive layer formed on one surface side of a base; and    an insulating layer formed to be in contact with an effective region effectively involved in detection of magnetism in said magneto-resistive layer without overlapping with said effective region, wherein:    said insulating layer comprises two or more layers;    the layer of said insulating layer closest to said base is made of a metal or semiconductor oxide; and    said layer of said insulating layer closest to said base extends over end faces of a plurality of layers made of different materials from one another, said plurality of layers making up said magneto-resistive layer, and is in contact with the end faces of said plurality of layers with the same materials.    
     
     
         2 . A magneto-resistive device according to  claim 1 , wherein said oxide is an oxide of a material selected from a group consisting of Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Zr, Nb, Mo, Hf, Ta, and W.  
     
     
         3 . A magneto-resistive device according to  claim 1  wherein said effective region is a region in which a current flows in a direction substantially perpendicular to the film surface in said magneto-resistive layer.  
     
     
         4 . A magneto-resistive device according to  claim 3 , wherein said magneto-resistive layer includes a tunnel barrier layer formed on one surface side of a free layer, a pinned layer formed on one surface side of said tunnel barrier layer opposite to said free layer, and a pin layer formed on one surface side of said pinned layer opposite to said tunnel barrier layer.  
     
     
         5 . A method of manufacturing a magneto-resistive device comprising the steps of: 
 depositing constituent layers making up a magneto-resistive layer on a base;    patterning one or more layers of said constituent layers;    depositing an oxidizable layer in a region in which said one or more layers of said constituent layers have been removed by the patterning;    oxidizing said oxidizable layer; and    depositing an insulating layer on said oxidizable layer.    
     
     
         6 . A method of manufacturing a magneto-resistive device according to  claim 5 , wherein: 
 said step of oxidizing includes the step of placing said base in the atmosphere to naturally oxidize said oxidizable layer.    
     
     
         7 . A method of manufacturing a magneto-resistive device according to  claim 5 , further comprising the step of performing dry etching for cleaning the surface immediately before said step of depositing said insulating layer.  
     
     
         8 . A method of manufacturing a magneto-resistive device according to  claim 7 , wherein said step of performing dry etching includes the step of performing the dry etching in the same vacuum chamber in which said step of depositing said insulating layer is performed.  
     
     
         9 . A method of manufacturing a magneto-resistive device according to  claim 7 , wherein said oxidizable layer substantially remains after said step of performing dry etching and after said step of depositing said insulating layer.  
     
     
         10 . A method of manufacturing a magneto-resistive device according to  claim 7 , wherein said oxidizable layer is substantially removed by said step of performing dry etching.  
     
     
         11 . A method of manufacturing a magneto-resistive device according to  claim 5 , further comprising the step of removing said oxidizing layer before said step of depositing said insulating layer.  
     
     
         12 . A method of manufacturing a magneto-resistive device according to  claim 5 , wherein said oxidizable layer is formed of a single-layer film or a composite-layer film made of one or more materials selected from a group consisting of Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Zr, Nb, Mo, Hf, Ta, and W.  
     
     
         13 . A method of manufacturing a magneto-resistive device according to  claim 5 , wherein said magneto-resistive device includes an effective region effectively involved in detection of magnetism in said magneto-resistive layer, said effective region being a region in which a current flows in a direction substantially perpendicular to the film surface in said magneto-resistive layer.  
     
     
         14 . A method of manufacturing a magneto-resistive device according to  claim 5 , wherein said magneto-resistive layer includes a tunnel barrier layer formed on one surface side of a free layer, a pinned layer formed on one surface side of said tunnel barrier layer opposite to said free layer, and a pin layer formed on one surface side of said pinned layer opposite to said tunnel barrier layer.  
     
     
         15 . A method of manufacturing a magneto-resistive device comprising the steps of: 
 depositing constituent layers making up a magneto-resistive layer on a base;    patterning one or more layers of said constituent layers;    depositing a layer formed of a single-layer film or a composite-layer film made of a metal and/or a semiconductor in a region in which said one or more layers of said constituent layers have been removed by the patterning;    removing said layer formed of a single-layer film or a composite-layer film made of a metal and/or a semiconductor; and    depositing an insulating layer in the region in which said one or more layers of said constituent layers have been removed by the patterning after said step of removing said layer.    
     
     
         16 . A method of manufacturing a magneto-resistive device according to  claim 15 , further comprising the step of performing dry etching for cleaning the surface immediately before said step of depositing said insulating layer, 
 said step of performing dry etching additionally serving as said step of removing.    
     
     
         17 . A method of manufacturing a magneto-resistive device according to  claim 16 , wherein said step of performing dry etching includes the step of performing the dry etching in the same vacuum chamber in which said step of depositing said insulating layer is performed.  
     
     
         18 . A method of manufacturing a magneto-resistive device according to  claim 15 , wherein said layer formed of a single-layer film or a composite-layer film made of a metal and/or a semiconductor is formed of a single-layer film or a composite-layer film made of one or more materials selected from a group consisting of Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Zr, Nb, Mo, Hf, Ta, W, Ru, Rh, Pd, Ag, Re, Os, Ir, Pt, and Au.  
     
     
         19 . A method of manufacturing a magneto-resistive device according to  claim 15 , wherein said layer formed of a single-layer film or a composite-layer film made of a metal and/or a semiconductor is an oxidizable layer.  
     
     
         20 . A method of manufacturing a magneto-resistive device according to  claim 19 , wherein said oxidizable layer is formed of a single-layer film or a composite-layer film made of one or more materials selected from a group consisting of Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Zr, Nb, Mo, Hf, Ta, and W.  
     
     
         21 . A method of manufacturing a magneto-resistive device according to  claim 15 , wherein said magneto-resistive device includes an effective region effectively involved in detection of magnetism in said magneto-resistive layer, said effective region being a region in which a current flows in a direction substantially perpendicular to the film surface in said magneto-resistive layer.  
     
     
         22 . A method of manufacturing a magneto-resistive device according to  claim 15 , wherein said magneto-resistive layer includes a tunnel barrier layer formed on one surface side of a free layer, a pinned layer formed on one surface side of said tunnel barrier layer opposite to said free layer, and a pin layer formed on one surface side of said pinned layer opposite to said tunnel barrier layer.  
     
     
         23 . A magnetic head comprising: 
 a base; and    a magneto-resistive device according to  claim 1 , said magneto-resistive device being supported by said base.    
     
     
         24 . A head suspension assembly comprising: 
 a magnetic head according to  claim 23;  and    a suspension for supporting said magnetic head mounted near a leading end thereof.    
     
     
         25 . A magnetic disk apparatus comprising: 
 a head suspension assembly according to  claim 24;     an arm for supporting said head suspension assembly; and    an actuator for moving said arm to position said magnetic head.