Method for manufacturing a surface-treated silicon substrate for magnetic recording medium

Abstract

Provided is a textured silicon substrate for a magnetic disk, comprising a magnetic film in which magnetic anisotropy can be attained and high recording density can be achieved, while ensuring the flying stability of a head by controlling the surface roughness of the substrate through texturing. Especially, provided is a surface-treated silicon substrate for a magnetic disk, comprising a texture formed on a surface of a silicon substrate comprising an oxide film of 0 to 2 nm thickness, and a magnetic recording medium comprising the surface-treated silicon substrate. Also provided is a method for manufacturing a surface-treated silicon substrate for a magnetic disk, comprising steps of: removing or reducing an oxide film on a surface of a silicon substrate; and forming a texture on the surface of the silicon substrate having the oxide film removed or reduced using a free abrasive-containing slurry and a tape; and a magnetic recording medium comprising the silicon substrate.

1 . A surface-treated silicon substrate for a magnetic disk comprising a texture formed on a surface of the silicon substrate comprising an oxide film of 0 to 2 nm thickness.  
   
   
       2 . The surface-treated silicon substrate according to  claim 1 , wherein said texture has 10 to 1000 lines per 1 μm in a radial direction, 10 to 1000 protrusions per 1 μm 2 , and average surface roughness (Ra) of 0.3 to 2.0 nm.  
   
   
       3 . The surface-treated silicon substrate according to  claim 1 , wherein said texture has average surface roughness of 0.3 to 2.0 nm in a radial direction, and average surface roughness of 0.1 to 2.0 nm in a circumferential direction.  
   
   
       4 . A magnetic recording medium comprising the surface-treated silicon substrate according to  claim 1 .  
   
   
       5 . A method for manufacturing a surface-treated silicon substrate for a magnetic disk comprising the steps of: 
 removing or reducing an silicon oxide film existing on a surface of a silicon substrate; and    forming a texture on the surface of the silicon substrate having the oxide film removed or reduced using a free abrasive-containing slurry and a tape.    
   
   
       6 . The method for manufacturing a surface-treated silicon substrate for a magnetic disk according to  claim 5 , wherein said step of removing or reducing a silicon oxide film results in the oxide film having thickness of 2 nm or less.  
   
   
       7 . The method for manufacturing a surface-treated silicon substrate according to  claim 5 , wherein said step of forming a texture results in 10 to 1000 lines per 1 μm in a radial direction, 10 to 1000 protrusions per 1 μm 2 , and the average surface roughness (Ra) of 0.3 to 2.0 nm on the surface of the silicon substrate  
   
   
       8 . The method for manufacturing a surface-treated silicon substrate according to  claim 5 , wherein said step of forming a texture results in the average roughness in a radial direction being 0.3 to 2.0 nm, and the average roughness in a circumferential direction being 0.1 to 2.0 nm on the surface of the silicon substrate.  
   
   
       9 . The method for manufacturing a surface-treated silicon substrate according to  claim 5 , wherein said abrasive is a particle selected from a group consisting of diamond, aluminum, titanium oxide, silicon carbide and titanium carbide, and its average particle size is 300 nm or less.  
   
   
       10 . The method for manufacturing a surface-treated silicon substrate according to  claim 5 , wherein said step of removing or reducing an oxide film comprises polishing.  
   
   
       11 . The method for manufacturing a surface-treated silicon substrate according to  claim 5 , wherein said step of removing or reducing an oxide film comprises use of a chemical liquid.  
   
   
       12 . The method for manufacturing a surface-treated silicon substrate according to  claim 10 , wherein said chemical liquid is a fluorine-containing compound.  
   
   
       13 . A magnetic recording medium comprising the surface-treated silicon substrate manufactured in the method according to  claim 5.