Perpendicular write head with tapered main pole

Abstract

Prior art designs of single pole writers have been limited by premature saturation at the tip. This limits the head field that can be achieved without simultaneously widening the write profile. This problem has bee solved by means of a vertical main pole whose thickness has its conventional value a short distance from the tip but that tapers down to a significantly reduced value as it approaches the tip. A process for manufacturing this tapered tip design is also presented.

1 . A method to increase a head field from a single vertical pole, having an air bearing surface, comprising: 
 tapering said pole whereby, over a distance of between about 0.1 and 4 microns, its thickness is reduced from between about 0.2 and 2 microns to a lesser thickness of between about 0.1 and 0.4 microns; and    whereby said lesser thickness extends from said air bearing surface for a distance of no more than about 0.2 and 0.4 microns.    
   
   
       2 . The method of  claim 1  wherein said increased head field is between about 0.1 and 0.3 T.  
   
   
       3 . The method of  claim 1  wherein said tapered pole is selected from the group consisting of Ni, Fe, Co, and their alloys.  
   
   
       4 . The method of  claim 1  wherein, at its tip, said tapered pole has a moment of at least 1.8 T.  
   
   
       5 . A process to manufacture a magnetic write head, having a tapered single vertical pole, comprising: 
 on a substrate, depositing a return pole layer;    forming, on said return pole layer, a magnetic yoke that includes a well within which is a coil embedded in a layer of insulation that shares a common first upper surface with said yoke;    forming a trench, having sloping sides and a depth, that extends downwards from said first upper surface;    overfilling said trench with a first layer of a material that has a moment of at least 1.8 T and then planarizing until said first upper surface is just exposed, thereby forming a second upper surface;    then depositing a layer of a second material having a moment of at least 2 T, thereby forming said magnetic write head, including said tapered single vertical pole; and    forming an air bearing surface by planarizing in a plane normal to said upper surfaces.    
   
   
       6 . The process described in  claim 5  wherein said return pole is deposited to a thickness between about 0.5 and 5 microns.  
   
   
       7 . The process described in  claim 5  wherein said return pole is a material selected from the group consisting of Ni, Fe, Co, and their alloys.  
   
   
       8 . The process described in  claim 5  wherein said coil well is formed to a depth of between about 0.5 and 4 microns.  
   
   
       9 . The process described in  claim 5  wherein said insulating layer is aluminum oxide.  
   
   
       10 . The process described in  claim 5  wherein ion beam milling is used to form said trench.  
   
   
       11 . The process described in  claim 5  wherein the depth of said trench is between about 0.2 and 3 microns.  
   
   
       12 . The process described in  claim 11  wherein said trench depth is controlled through adjustment of said ion beam's dose and duration.  
   
   
       13 . The process described in  claim 5  wherein the sides of the trench slope at an angle between about 15 and 65 degrees from vertical.  
   
   
       14 . The process described in  claim 13  wherein said slope angle is controlled through adjustment of said ion beam's angle of incidence.  
   
   
       15 . The process described in  claim 5  wherein said yoke is a material selected from the group consisting of Ni, Fe, Co, and their alloys.  
   
   
       16 . The process described in  claim 5  wherein said first layer of a material that has a moment of at least 1.8 T is a material selected from the group consisting of Ni, Fe, Co, and their alloys.  
   
   
       17 . The process described in  claim 5  wherein said second layer of a material that has a moment of at least 2 T is a material selected from the group consisting of Ni, Fe, Co, and their alloys.  
   
   
       18 . The process described in  claim 5  wherein said return pole layer is located behind a trailing edge of said vertical pole.  
   
   
       19 . The process described in  claim 5  wherein said return pole layer is located in front of a leading edge of said vertical pole.  
   
   
       20 . A magnetic write head, having a tapered single vertical pole, comprising: 
 a return pole layer on a substrate;    on said return pole layer, a magnetic yoke that includes a well within which is a coil embedded in a layer of insulation that shares a common first upper surface with said yoke;    a trench, having sloping sides and a depth, that extends downwards from said first upper surface;    said trench being exactly filled with a first layer of a material capable of a magnetic moment of at least 1.8 T and a second upper surface;    on said second upper surface, a layer of a second material having a capable of a magnetic moment of at least 2 T; and    an air bearing surface in a plane normal to said upper surfaces.    
   
   
       21 . The magnetic write head described in  claim 20  wherein said return pole is deposited to a thickness between about 0.5 and 5 microns.  
   
   
       22 . The magnetic write head described in  claim 20  wherein said return pole is a material selected from the group consisting of Ni, Fe, Co, and their alloys.  
   
   
       23 . The magnetic write head described in  claim 20  wherein said coil well has a depth of between about 0.5 and 4 microns.  
   
   
       24 . The magnetic write head described in  claim 20  wherein said insulating layer is aluminum oxide.  
   
   
       25 . The magnetic write head described in  claim 20  wherein the depth of said trench is between about 0.2 and 3 microns.  
   
   
       26 . The magnetic write head described in  claim 20  wherein the sides of the trench slope at an angle between about 15 and 65 degrees from vertical.  
   
   
       27 . The magnetic write head described in  claim 20  wherein said yoke is a material selected from the group consisting of Ni, Fe, Co, and their alloys.  
   
   
       28 . The magnetic write head described in  claim 20  wherein said first layer of a material that is capable of a magnetic moment of at least 1.8 T is a material selected from the group consisting of Ni, Fe, Co, and their alloys.  
   
   
       29 . The magnetic write head described in  claim 20  wherein said second layer of a material that is capable of a magnetic moment of at least 2 T is a material selected from the group consisting of Ni, Fe, Co, and their alloys.  
   
   
       30 . A magnetic write head, having an ABS, a main pole, and a trailing edge, comprising: 
 said trailing edge being tapered at an angle of 15 to 60 degrees from vertical;    wherein said taper of the trailing edge begins at a distance of less than about 0.3 microns from said ABS;    wherein said taper of the trailing edge is present over a distance of up to about 2 microns from said ABS;    behind said main pole, a trailing shield having a thickness between about 0.05 and 0.5 microns;    wherein there is a constant horizontal separation between said main pole and said trailing shield; and    wherein said shield is tapered at an angle equal to said main pole taper angle.    
   
   
       31 . The magnetic write head described in  claim 30  wherein said constant separation between said main pole and said trailing shield is between about 0.02 and 0.2 microns.  
   
   
       32 . The magnetic write head described in  claim 30  further comprising one or more side shields around said main pole.  
   
   
       33 . The magnetic write head described in  claim 30  further comprising: 
 a return pole;    on said return pole, a magnetic yoke that includes a well within which is a coil embedded in a layer of insulation having a first upper surface;    a trench, having a floor and a sloping sidewall, formed from said first upper surface;    a first layer of a material, capable of a magnetic moment of at least 1.8 T, that more than fills said trench and that has a second upper surface; and    on said second upper surface, a layer of a second material capable of a magnetic moment of at least 2 T.