Heat assisted magnetic recording medium and method for fabricating the same

Abstract

A novel heat assisted magnetic recording (HAMR) medium and the fabrication method therefor are provided. The exchange coupling effect occurring at the interface of FePt/CoTb double layers is adopted, and thus the resulting magnetic flux would be sufficient enough to be detected and readout under the room temperature. The provided HAMR medium exhibits a relatively high saturation magnetization and perpendicular coercivity, and thus possesses a great potential for the ultra-high density recording application.

1 . A method for fabricating a heat assisted magnetic recording medium, comprising steps of: (a) providing a substrate; (b) performing a thermal process to said substrate; (c) forming an underlayer of Cr on said substrate; (d) forming a buffer layer of Pt on said underlayer; (e) forming a layer of Fe x Pt 100-x  on said buffer layer; and(f) forming a layer of Co y Tb 100-y  on said layer of Fe x Pt 100-x . 
     
     
         2 . The method according to  claim 1 , wherein said step (b) further comprising a step of: heating said substrate to a first temperature. 
     
     
         3 . The method according to  claim 2 , wherein said first temperature is less than 800° C. 
     
     
         4 . The method according to  claim 3 , wherein said first temperature is 350° C. 
     
     
         5 . The method according to  claim 2 , wherein in said step (b), said thermal process is performed for 5 to 90 minutes. 
     
     
         6 . The method according to  claim 6 , wherein in said step (b), said first temperature is 350° C., and said thermal process is performed for 30 minutes. 
     
     
         7 . The method according to  claim 1 , wherein in said step (b), said thermal process is performed under a pressure ranged from 1×10 −9  to 1×10 −6  Torr. 
     
     
         8 . The method according to  claim 1 , wherein in said step (c), said buffer layer of Cr is formed on said substrate under a temperature of 350° C. 
     
     
         9 . The method according to  claim 1 , wherein in said step (d), said buffer layer of Pt is formed on said underlayer under a second temperature below 800° C. 
     
     
         10 . The method according to  claim 9 , wherein said second temperature is 350° C. 
     
     
         11 . The method according to  claim 1 , wherein in said step (e), said layer of Fe x Pt 100-x  is formed on said buffer layer under a third temperature below 800° C. 
     
     
         12 . The method according to  claim 11 , wherein said third temperature is 420° C. 
     
     
         13 . The method according to  claim 1 , wherein in said step (f), said layer of Co y Tb 100-y  is formed on said layer of Fe x Pt 100-x  under a fourth temperature below 50° C. 
     
     
         14 . The method according to  claim 13 , wherein said fourth temperature is an ambient temperature. 
     
     
         15 . The method according to  claim 1 , wherein said underlayer of Cr, said buffer layer of Pt, said layer of Fe x Pt 100-x  and said layer of Co y Tb 100-y  are formed by DC magnetron sputtering in an ultrahigh vacuum sputtering chamber. 
     
     
         16 . The method according to  claim 15 , wherein said underlayer of Cr, said buffer layer of Pt, said layer of Fe x Pt 100-x  and said layer of Co y Tb 100-y  are deposited under an argon pressure ranged from 2 to 12 mTorr. 
     
     
         17 . The method according to  claim 16 , wherein said argon pressure is 5 mTorr. 
     
     
         18 . The method according to  claim 16 , wherein said layer of Fe x Pt 100-x  is deposited by DC magnetron sputtering with a first DC power ranged from 0.2 to 0.5 W/cm 2 . 
     
     
         19 . The method according to  claim 18 , wherein said first DC power is 0.22 W/cm 2 . 
     
     
         20 . The method according to  claim 15 , wherein said layer of Co y Tb 100-y  is deposited by DC magnetron sputtering with a second DC power ranged from 1 to 4 W/cm 2 . 
     
     
         21 . The method according to  claim 20 , wherein said second DC power is 2.96 W/cm 2 . 
     
     
         22 . The method according to  claim 1 , further comprising a step of: (g) forming a passiviation layer on said layer of Co y Tb 100 -y. 
     
     
         23 . The method according to  claim 22 , wherein said passiviation layer is formed by magnetron sputtering with an RF power ranged from 2 to 7 W/cm 2 . 
     
     
         24 . The method according to  claim 23 , wherein said RF power is 2.47 W/cm 2 .