Graded side shield gap reader

Abstract

Embodiments of the present invention generally include magnetoresistive heads, such as read heads, having a sensor structure and side shields disposed adjacent to the sensor structure. The distance between the side shields and the sensor structure increase in a direction from an ABS in the off-track direction. The magnetoresistive heads may include tapered surfaces on the side shields or sensor structure, or may include stepped surfaces on the side shields or sensor structure.

What is claimed is: 
     
         1 . A magnetoresistive head, comprising:
 a sensor structure;   a first side shield disposed on a first side of the sensor structure;   a second side shield disposed on a second side of the sensor structure;   wherein the first side shield is spaced from the sensor structure by a first distance at an air bearing surface and a second distance at a location spaced from the air bearing surface, wherein the second distance is greater than the first distance; and   wherein the distance between the first side shield and the sensor structure tapers from the ABS to the location spaced from the air bearing surface.   
     
     
         2 . The magnetoresistive head of  claim 1 , wherein adjacent edges of the first side shield and the second side shield are substantially parallel. 
     
     
         3 . The magnetoresistive head of  claim 1 , wherein a first edge of the sensor structure adjacent the first side shield is parallel to a second edge of the sensor structure adjacent to the second side shield. 
     
     
         4 . The magnetoresistive head of  claim 1 , further comprising an electrically insulating material disposed between the sensor structure and each of the first side shield and the second side shield. 
     
     
         5 . The magnetoresistive head of  claim 4 , wherein the electrically insulating material includes aluminum oxide. 
     
     
         6 . The magnetoresistive head of  claim 5 , wherein adjacent edges of the first side shield and the second side shield are substantially parallel. 
     
     
         7 . The magnetoresistive head of  claim 1 , wherein an edge of the sensor structure adjacent the first side shield includes a first tapered portion disposed at a first angle relative to an edge of the side shield and a second tapered portion disposed at a second angle relative to the edge of the side shield, wherein the first angle is different than the second angle. 
     
     
         8 . The magnetoresistive head of  claim 1 , wherein the sensor structure includes an under layer, an antiferromagnetic layer, a pinned magnetic layer, an insulation layer, a free layer and a gap layer. 
     
     
         9 . A magnetoresistive head, comprising:
 a sensor structure;   a first side shield disposed on a first side of the sensor structure, wherein an edge of the first side shield adjacent the sensor structure forms a stepped surface; and   a second side shield disposed on a second side of the sensor structure, wherein an edge of the second side shield adjacent the sensor structure forms a stepped surface.   
     
     
         10 . The magnetoresistive head of  claim 9 , wherein the sensor structure includes an under layer, an antiferromagnetic layer, a pinned magnetic layer, an insulation layer, a free layer and a gap layer. 
     
     
         11 . The magnetoresistive head of  claim 9 , further comprising an electrically insulating material disposed between the sensor structure and each of the first side shield and the second side shield. 
     
     
         12 . The magnetoresistive head of  claim 11 , wherein the electrically insulating material includes aluminum oxide. 
     
     
         13 . The magnetoresistive head of  claim 9 , wherein the first side shield and the second side shield each comprise a least one material selected from the group of NiFe, CoFe, and NiCoFe. 
     
     
         14 . The magnetoresistive head of  claim 9 , wherein the first side shield and the second side shield each comprise a first layer of NiFe, a second layer of Ru, and a third layer of NiFe. 
     
     
         15 . A magnetoresistive head, comprising:
 a sensor structure having a first edge on a first side thereof and a second edge on a side thereof, the first edge being parallel to the second edge;   a first side shield disposed on the first side of the sensor structure, the first side shield having an edge with a first portion parallel to the first edge of the sensor structure and a second portion angled with respect to the first edge of the sensor structure;   a second side shield disposed on the second side of the sensor structure, the second side shield having an edge with a first portion parallel to the second edge of the sensor structure and a second portion angled with respect to the second edge of the sensor structure;   wherein a distance between the first edge of the sensor structure and the first portion of the first side shield is less than the gap between the first edge of the sensor structure and the second portion of the first side shield; and   wherein a distance between the second edge of the sensor structure and the first portion of the second side shield is less than the gap between the second edge of the sensor structure and the second portion of the second side shield.   
     
     
         16 . The magnetoresistive head of  claim 15 , wherein the first side shield and the second side shield each comprise a first layer of NiFe, a second layer of Ru, and a third layer of NiFe. 
     
     
         17 . The magnetoresistive head of  claim 15 , wherein the first side shield and the second side shield each comprise a least one material selected from the group of NiFe, CoFe, and NiCoFe. 
     
     
         18 . The magnetoresistive head of  claim 15 , wherein the sensor structure includes an under layer, an antiferromagnetic layer, a pinned magnetic layer, an insulation layer, a free layer and a gap layer. 
     
     
         19 . A magnetoresistive head, comprising:
 a sensor structure having a first edge on a first side thereof and a second edge on a side thereof, each of the first edge and the second edge having a first portion parallel with one another and a second portion disposed at an angle with respect to the first portions;   a first side shield disposed on the first side of the sensor structure, the first side shield having a first edge parallel with the first portion of the first edge of the sensor structure;   a second side shield disposed on the second side of the sensor structure, the second side shield having a first edge parallel with the first portion of the second edge of the sensor structure;   wherein a distance between the first edge of the first side shield and the first portion of the first edge of the sensor structure is less than the gap between the first edge of the first side shield and the second portion of the first edge of the sensor structure; and   wherein a distance between the first edge of the second side shield and the first portion of the second edge of the sensor structure is less than the gap between the first edge of the second side shield and the second portion of the second edge of the sensor structure.   
     
     
         20 . The magnetoresistive head of  claim 20 , wherein the sensor structure includes an under layer, an antiferromagnetic layer, a pinned magnetic layer, an insulation layer, a free layer and a gap layer.