Bit patterned media

Abstract

The invention relates to bit patterned recording media having a stop layer for chemical mechanical polishing. One embodiment of the present invention is a method of manufacturing a magnetic recording medium comprising the step of planarizing by chemical mechanical polishing until the stop layer is reached. The present invention also provides a magnetic recording medium having a stop layer.

1 - 10 . (canceled) 
     
     
         11 . A method of manufacturing a magnetic recording medium comprising:
 forming a magnetic layer upon a substrate, the magnetic layer comprising an array of discrete magnetic bits separated by a non-magnetic filler material; depositing a stop layer upon the magnetic layer; depositing an excess layer upon the stop layer; and   planarizing by chemical mechanical polishing until the stop layer is reached.   
     
     
         12 . The method of  claim 11 , wherein the filler material is selected from Ah03, Si0 2 , SiO x N y , and combinations thereof. 
     
     
         13 . The method of  claim 11 , wherein the filler material comprises Ah03. 
     
     
         14 . The method of  claim 11 , wherein the stop layer is selected from carbon, platinum, gold, chromium, ruthenium, diamond, tungsten, SiC, SiO x N y , NiCu, and combinations thereof. 
     
     
         15 . The method of  claim 11 , wherein the stop layer comprises carbon. 
     
     
         16 . The method of  claim 11 , wherein the excess layer comprises Ah03. 
     
     
         17 . The method of  claim 11 , wherein the stop layer has a thickness of about 2 to about 200 nm. 
     
     
         18 . The method of  claim 17 , wherein the stop layer has a thickness of about 2 to about 10 nm. 
     
     
         19 . The method of  claim 11 , wherein the step of planarizing by chemical mechanical polishing comprises measuring an increase in induced polishing friction to determine the stop layer has been reached. 
     
     
         20 . The method of  claim 11 , wherein the step of planarizing by chemical mechanical polishing comprises measuring changes in surface optical reflectivities to determine the stop layer has been reached. 
     
     
         21 . The method of  claim 11 , wherein the step of planarizing by chemical mechanical polishing comprises measuring changes in electrical currents to determine the stop layer has been reached. 
     
     
         22 . A magnetic recording medium, comprising:
 a substrate;   an array of discrete magnetic bits on the substrate, wherein the magnetic bits have a width defined by a distance between a first side surface and a second side surface;   regions of a non-magnetic filler material between the discrete magnetic bits in the array; an overlying layer in direct contact with the magnetic bits; and   a stop layer between the regions of non-magnetic filler material and the overlying layer, wherein the stop layer is adjacent to the first and the second side surfaces of the magnetic bits.   
     
     
         23 . The magnetic recording medium of  claim 22 , wherein the magnetic bits in the array have a thickness defined by a distance between a first surface thereof in direct contact with the substrate and a second surface thereof in direct contact with the overlying layer, and wherein a combined thickness of the non-magnetic filler material between the bits and the stop layer adjacent the bits is substantially equal to not greater than a thickness of the bits. 
     
     
         24 . The magnetic recording medium of  claim 22 , wherein the CMP removal rate selectivity of the stop layer is at least about 80 times the CMP removal rate selectivity of either of the magnetic bits or the non-magnetic filler material. 
     
     
         25 . The magnetic recording medium of  claim 22 , wherein the overlying layer comprises one or more cap layers and lubricant layers. 
     
     
         26 . A magnetic recording medium, comprising:
 a substrate;   an array of discrete magnetic bits on the substrate, wherein the magnetic bits have a width defined by a distance between a first side surface and a second side surface, and wherein the magnetic bits have an exposed top surface;   
       regions of a non-magnetic filler material between the discrete magnetic bits in the array; and
 a discontinuous stop layer overlying the regions of non-magnetic filler material, wherein the stop layer abuts the first and the second side surfaces of the magnetic bits in the array, and wherein herein the stop layer comprises an array of apertures occupied by the magnetic bits in the array. 
 
     
     
         27 . The magnetic recording medium of claim  1 , wherein a combined thickness of the non-magnetic filler material and the stop layer is substantially equal to a thickness of the magnetic bits in the array.