Magnetic recording medium and method of manufacturing the same

Abstract

According to one embodiment, a magnetic recording medium includes a data region and a servo region adjacent to the data region and including a magnetic recording layer, the magnetic recording layer including first and second patterned regions adjacent to each other, the first patterned region including a first nonmagnetic matrix and first magnetic particles dispersed in the first nonmagnetic matrix and having magnetization oriented in a first direction, the second patterned region includes a second nonmagnetic matrix and second magnetic particles dispersed in the second nonmagnetic matrix and having magnetization oriented in a second direction opposite to the first direction, sizes of the first magnetic particles being smaller than sizes of the second magnetic particles.

1 . A magnetic recording medium, comprising:
 a data region; and   a servo region adjacent to the data region and including a magnetic recording layer, wherein the magnetic recording layer comprises first and second patterned regions adjacent to each other, the first patterned region comprises a first nonmagnetic matrix and first magnetic particles dispersed in the first nonmagnetic matrix and has magnetization oriented in a first direction, the second patterned region comprises a second nonmagnetic matrix and second magnetic particles dispersed in the second nonmagnetic matrix and has magnetization oriented in a second direction opposite to the first direction, and sizes of the first magnetic particles are smaller than sizes of the second magnetic particles.   
     
     
         2 . The magnetic recording medium according to  claim 1 , wherein either of the first and second patterned regions forms a pattern corresponding to a servo signal. 
     
     
         3 . The magnetic recording medium according to  claim 1 , wherein the servo region further includes an underlayer on which the magnetic recording layer is stacked, and protrusions are formed on the underlayer at positions where the first magnetic particles are formed, and the surface of the underlayer is flat at a position corresponding to the second patterned region. 
     
     
         4 . The magnetic recording medium according to  claim 3 , wherein the underlayer is made of ruthenium (Ru) or Ru alloy. 
     
     
         5 . A magnetic recording medium, comprising:
 an underlayer;   an interlayer formed on the underlayer, wherein the interlayer comprises first and second regions adjacent to each other, the first region has holes that pass from a surface of the underlayer to a surface of the interlayer, and the second region has a flat surface;   first magnetic particles formed on the first region of the underlayer, wherein the first magnetic particles comprise easy axes of magnetization;   a first nonmagnetic matrix formed on the first region and surrounding the first magnetic particles; and   a non-oriented part formed on the second region, wherein the non-oriented part comprises a nonmagnetic material and a magnetic material, and the magnetic material has an easy axis of magnetization different from easy axes of magnetization of the first magnetic particles.   
     
     
         6 . The magnetic recording medium according to  claim 5 , wherein the magnetic material comprises dispersed magnetic particles in the nonmagnetic material, and sizes of the first magnetic particles are smaller than sizes of the dispersed magnetic particles. 
     
     
         7 . The magnetic recording medium according to  claim 5 , wherein the underlayer is made of ruthenium (Ru) or Ru alloy. 
     
     
         8 . The magnetic recording medium according to  claim 5 , wherein the interlayer is made of oxide(s), nitride(s) or organic substance(s). 
     
     
         9 . The magnetic recording medium according to  claim 8 , wherein the interlayer is made of SiO 2 , Al 2 O 3 , Ta 2 O 5 , TiO 2 , Si 3 N 4 , AlN, TaN, photoresist, or organosilicate. 
     
     
         10 . A method of manufacturing a magnetic recording medium, comprising:
 forming a resist layer on an underlayer;   imprinting a stamper having a concavo-convex pattern on the resist layer to transfer the concavo-convex pattern onto a surface of the resist layer;   forming a region having protrusions and a region having a flat surface to the underlayer by etching the underlayer with use of the patterned resist layer as a mask;   removing the resist layer from the underlayer; and   forming a magnetic recording layer on the underlayer.   
     
     
         11 . The method according to  claim 10 , wherein the underlayer is made of ruthenium (Ru) or Ru alloy. 
     
     
         12 . A method of manufacturing a magnetic recording medium, comprising:
 forming an interlayer on an underlayer, the interlayer including first and second regions adjacent to each other and made of oxide(s), nitride(s) or organic substance(s);   forming a resist layer on the interlayer;   imprinting a stamper having a concavo-convex pattern on the resist layer to transfer the concavo-convex pattern onto a surface of the resist layer;   etching the interlayer using the patterned resist layer as a mask to form holes that pass from a top-surface of the interlayer to a bottom-surface of the interlayer in the first region;   removing the resist layer from the interlayer to form the holes and to form a flat surface on in the second region; and   forming a magnetic recording layer on the first region and the second region.   
     
     
         13 . The method according to  claim 12 , wherein etching the interlayer is performed such that the second region of the interlayer remains on the underlayer. 
     
     
         14 . The method according to  claim 12 , wherein etching the interlayer is performed such that the second region of the interlayer is removed. 
     
     
         15 . The method according to  claim 12 , wherein the interlayer is made of SiO 2 , Al 2 O 3 , Ta 2 O 5 , TiO 2 , Si 3 N 4 , AlN, TaN, photoresist, or organosilicate. 
     
     
         16 . The method according to  claim 12 , wherein the underlayer is made of ruthenium (Ru) or Ru alloy.