Read head having shaped read sensor-biasing layer junctions using partial milling

Abstract

A read head and a magnetic hard disk drive having a read head layer stack which has been partially milled to within a partial milling range to form a shaped junction and a hard bias layer which is in contact with the shaped junction of the wafer stack.

1 . A read head for a hard disk drive, produced by the process comprising:
 A) depositing a first shield layer to begin a wafer stack;   B) depositing a dielectric layer on said first shield layer;   C) depositing a first seed layer on said dielectric layer;   D) depositing an AFM layer on said first seed layer;   E) depositing at least one pinned layer on said AFM layer;   F) depositing a spacer layer on said at least one pinned layer;   G) depositing a free layer on said spacer layer;   H) depositing a cap layer on said free layer to complete said wafer stack;   I) depositing a mask layer on said cap layer; and   J) partially milling said wafer stack with a milling source to remove material from wafer stack layers to within a partial milling range which extends to a partial milling depth having a depth endpoint, to form a shaped junction.   
   
   
       2 . The read head of  claim 1 , wherein:
 J) includes milling at high incidence.   
   
   
       3 . The read head of  claim 2 , wherein:
 J) further includes milling at razing incidence.   
   
   
       4 . The read head of  claim 3 , wherein:
 J) includes multiple cycles of milling at both high incidence and razing incidence.   
   
   
       5 . The read head of  claim 4 , further comprising:
 K) depositing a second seed layer.   
   
   
       6 . The read head of  claim 5 , further comprising:
 L) depositing a hard bias layer.   
   
   
       7 . The read head of  claim 6 , further comprising:
 M) depositing a leads layer.   
   
   
       8 . The read head of  claim 7 , further comprising:
 N) lifting off said mask layer.   
   
   
       9 . The read head of  claim 6 , wherein:
 J) includes shaping portions of said wafer stack so that the junction between said portions of said wafer stack and said hard bias layer is shaped.   
   
   
       10 . A magnetic hard drive comprising:
 a read sensor having a centrally disposed wafer stack including:
 a first shield layer; 
 a dielectric layer on said first shield layer; 
 a first seed layer on said dielectric layer; 
 an AFM layer on said first seed layer; 
 at least one pinned layer on said AFM layer; 
 a spacer layer on said at least one pinned layer; 
 a free layer on said spacer layer; and 
 a cap layer on said free layer; and 
   at least one laterally disposed second seed layer;   at least one laterally disposed hard bias layer; and   at least one laterally disposed electronic leads layer;   wherein said wafer stack has been shaped with a milling source to remove material from wafer stack layers to within a partial milling range which extends to a partial milling depth having a depth endpoint, to form a shaped junction.   
   
   
       11 . The magnetic hard drive of  claim 10 , wherein:
 said shaped wafer stack includes shaped junctions between portions of said free layer and portions of said at least one hard bias layer.   
   
   
       12 . The magnetic hard drive of  claim 10 , wherein:
 said partial milling range extends from below said free layer to a partial milling depth having a depth endpoint which lies within said first seed layer.   
   
   
       13 . The magnetic hard drive of  claim 12 , wherein:
 said partial milling depth lies within said partial milling range and where the depth endpoint lies within said AFM layer.