Method for producing a master disk of a recording medium, method for producing a stamper, method for producing a recording medium, master disk of a recording medium, stamper of a recording medium, and recording medium

Abstract

A method for producing a master disk 105 for an optical disk 110 includes a layer forming step of forming a heat-sensitive material layer 102 on a substrate 101 , an exposure step of exposing the heat-sensitive material layer 102 partially to a laser beam, and a pit and land pattern forming step of forming a pattern of pits and lands by means of the difference between the etching rates of the exposed portion and the unexposed portion of the heat-sensitive material layer 102 . The heat-sensitive material layer 102 includes at least Sb and O. When the composition ratio of O is defined as x (atom %), x is 3 or more and 50 or less.

1 . A method of producing a master disk for a recording medium, comprising: 
 a layer forming step of forming a heat-sensitive material layer on a substrate;    an exposure step of partially exposing said heat-sensitive material layer to a laser beam; and    a pit and land pattern forming step which uses a difference between etching rates of an exposed portion and an unexposed portion of said heat-sensitive material layer to form a pattern of pits and lands, wherein    said heat-sensitive material layer comprises at least Sb and O, and    when the composition ratio of O is defined as x (atom %), x is defined as 3≦x≦50.    
     
     
         2 . The method of producing a master disk for a recording medium according to  claim 1 , wherein 
 said heat-sensitive material layer contains, as an additive, at least one element selected from the group consisting of Ag, Al, Au, Cr, Cu, Fe, Ge, Mo, Nb, Os, Pd, Se, Si, Ta, Te, Ti, V, and W, and    when the composition ratio of said additive is defined as y (atom %), y is defined as 1≦y≦30.    
     
     
         3 . The method of producing a master disk for a recording medium according to  claim 2 , wherein said additive comprises at least one element selected from the group consisting of Au, Ge, Te, Nb, Pd, Si, Ti, and W.  
     
     
         4 . The method of producing a master disk for a recording medium according to  claim 1 , wherein in said layer forming step, a reactive sputtering process is used.  
     
     
         5 . The method of producing a master disk for a recording medium according to  claim 4 , wherein a sputtering gas used in said layer forming step contains at least oxygen, and the oxygen partial pressure is 0.005 Pa or more.  
     
     
         6 . The method of producing a master disk for a recording medium according to  claim 1 , wherein prior to said pit and land pattern forming step, the method further comprises an annealing step for heating said heat-sensitive material layer such that the temperature of said heat-sensitive material layer is greater than or equal to 50° C. and less than or equal to 300° C.  
     
     
         7 . The method of producing a master disk for a recording medium according to  claim 6 , wherein said annealing step is performed after said layer forming step and said exposure step.  
     
     
         8 . The method of producing a master disk for a recording medium according to  claim 6 , wherein said annealing step is performed after said layer forming step and prior to said exposure step.  
     
     
         9 . The method of producing a master disk for a recording medium according to  claim 6 , wherein said annealing step is performed by applying a laser beam.  
     
     
         10 . The method of producing a master disk for a recording medium according to  claim 1 , wherein said pit and land pattern forming step is performed using an aqueous alkaline solution.  
     
     
         11 . The method of producing a master disk for a recording medium according to  claim 1 , further comprising a second layer forming step of forming a layer whose thermal conductivity is different from that of said heat-sensitive material layer and which contacts said substrate.  
     
     
         12 . The method of producing a master disk for a recording medium according to  claim 1 , wherein the time from completing the layer forming step to initiation of the pit and land pattern forming step is within 24 hours.  
     
     
         13 . A master disk produced by the method of producing a master disk for a recording medium according to  claim 1 .  
     
     
         14 . A stamper manufacturing method wherein a stamper for a recording medium is produced using the master disk according to  claim 13 .  
     
     
         15 . A stamper of a recording medium formed by using the master disk according to  claim 13 .  
     
     
         16 . A recording medium manufacturing method for producing a recording medium using the stamper according to  claim 15 .  
     
     
         17 . A recording medium formed with the stamper according to  claim 15.