Stamper, imprinting method, and method of manufacturing an information recording medium

Abstract

A stamper has stamper-side concave/convex patterns formed thereupon and is capable of manufacturing an information recording medium on which data track patterns and servo patterns are formed by concave/convex patterns. A plurality of types of convex parts with different heights from a reference plane, which is set between a front surface and a rear surface of the stamper, to protruding ends of the convex parts are formed in the stamper-side concave/convex patterns. Second convex parts, at least one part of which has the height that is higher than the height of a highest first convex part out of the convex parts formed in regions corresponding to the data track patterns, are formed in regions corresponding to the servo patterns.

1 . A stamper on which stamper-side concave/convex patterns are formed and which is capable of manufacturing an information recording medium on which data track patterns and servo patterns are formed by concave/convex patterns, 
 wherein a plurality of types of convex parts with different heights from a reference plane, which is set between a front surface and a rear surface of the stamper, to protruding ends of the convex parts are formed in the stamper-side concave/convex patterns, and second convex parts, at least one part of which has the height that is higher than the height of a highest first convex part out of the convex parts formed in regions corresponding to the data track patterns, are formed in regions corresponding to the servo patterns.    
     
     
         2 . A stamper according to  claim 1 , wherein in the stamper-side concave/convex patterns, third convex parts that are continuously formed along a direction corresponding to a radial direction oft the information recording medium are formed as the second convex parts, and 
 the third convex parts are formed so that the height thereof is higher than the height of the first convex part at positions where the length of the third convex parts in a direction corresponding to a circumferential direction of the information recording medium is longer than the length of the first convex part in the direction corresponding to the radial direction.    
     
     
         3 . A stamper according to  claim 1 , wherein in the stamper-side concave/convex patterns, parts corresponding to individual burst regions in burst patterns out of the servo patterns are composed of concave parts and fourth convex parts are formed around the concave parts as the second convex parts, and 
 the fourth convex parts are formed so that the height thereof is higher than the height of the first convex part in at least one part of each of the forth convex parts.    
     
     
         4 . A stamper according to  claim 3 , wherein the fourth convex parts are formed so that the height thereof is higher than the height of the first convex part across the entire stamper-side concave/convex patterns.  
     
     
         5 . An imprinting method comprising; 
 a stamper pressing process, which presses the stamper-side concave/convex patterns of a stamper according to  claim 1  onto a resin layer formed by applying a resin material onto a surface of a substrate; and    a stamper separating process, which separates the stamper from the resin layer, wherein the stamper pressing process and the stamper separating process are carried out in the mentioned order to transfer a concave/convex form of the stamper-side concave/convex patterns to the resin layer.    
     
     
         6 . A method of manufacturing an information recording medium using a concave/convex pattern transferred to the resin layer by the imprinting method according to  claim 5.