Pattern fortification for hdd bit patterned media pattern transfer

Abstract

A method and apparatus for forming a magnetic layer having a pattern of magnetic properties on a substrate is described. The method includes using a metal nitride hardmask layer to pattern the magnetic layer by plasma exposure. The metal nitride layer is patterned using a nanoimprint patterning process with a silicon oxide pattern negative material. The pattern is developed in the metal nitride using a halogen and oxygen containing remote plasma, and is removed after plasma exposure using a caustic wet strip process. All processing is done at low temperatures to avoid thermal damage to magnetic materials.

1 . A method of patterning a substrate, comprising:
 forming a metal nitride film on a magnetically active surface of the substrate;   patterning the metal nitride film to form protected domains of the magnetically active surface separated by unprotected domains of the magnetically active surface;   altering a magnetic property of the unprotected domains of the magnetically active surface by treating the substrate with a plasma; and   removing the metal nitride film to form a surface of the substrate having a pattern of magnetic properties.   
     
     
         2 . The method of  claim 1 , wherein the metal nitride film is a TiN film. 
     
     
         3 . The method of  claim 2 , wherein the metal of the metal nitride film comprises one or more metals from the group consisting of titanium, aluminum, tantalum, and tungsten. 
     
     
         4 . The method of  claim 1 , further comprising forming a protective overcoat over the metal nitride film. 
     
     
         5 . The method of  claim 4 , wherein the protective overcoat and the metal nitride film are removed by a wet strip process. 
     
     
         6 . The method of  claim 4 , wherein the protective overcoat comprises tungsten. 
     
     
         7 . The method of  claim 6 , wherein the protective overcoat is formed by a physical vapor deposition process. 
     
     
         8 . The method of  claim 1 , wherein treating the substrate with a plasma comprises immersing the substrate in the plasma. 
     
     
         9 . A method of patterning a substrate, comprising:
 forming a metal nitride film on a magnetically active surface of the substrate;   forming a patterning mask on the metal nitride film;   physically imprinting the patterning mask to form a pattern;   transferring the pattern into the metal nitride film to form protected domains of the magnetically active surface separated by unprotected domains of the magnetically active surface;   removing the patterning mask;   altering a magnetic property of the unprotected domains of the magnetically active surface by treating the substrate with a plasma; and   removing the metal nitride film to form a surface of the substrate having a pattern of magnetic properties.   
     
     
         10 . The method of  claim 9 , wherein the metal nitride film is a titanium nitride film, and the titanium nitride film is formed by a PVD process at a temperature less than about 200° C. 
     
     
         11 . The method of  claim 10 , wherein transferring the pattern into the titanium nitride film comprises exposing the substrate to a remote plasma. 
     
     
         12 . The method of  claim 11 , wherein exposing the substrate to a remote plasma comprises overetching the substrate. 
     
     
         13 . The method of  claim 11 , wherein treating the substrate with a plasma comprises immersing the substrate in an in-situ plasma and applying RF bias to the substrate. 
     
     
         14 . The method of  claim 13 , wherein removing the titanium nitride film comprises performing a wet strip process at a temperature below about 100° C. 
     
     
         15 . The method of  claim 14 , wherein the wet strip process comprises applying a solution of TMAH and hydrogen peroxide in water to the substrate. 
     
     
         16 . The method of  claim 9 , further comprising forming a protective overcoat on the metal nitride film. 
     
     
         17 . The method of  claim 16 , wherein the protective overcoat comprises tungsten. 
     
     
         18 . An apparatus for magnetically patterning substrate, comprising:
 a PVD chamber;   a physical patterning chamber;   an etch chamber; and   a plasma immersion chamber, wherein the PVD chamber, the physical patterning chamber, the etch chamber, and the plasma immersion chamber are coupled to a transfer chamber.   
     
     
         19 . The apparatus of  claim 18 , further comprising a wet strip chamber. 
     
     
         20 . The apparatus of  claim 19 , further comprising a substrate flipping module.