CONCAVE/CONVEX PATTERN FORMING METHOD AND INFORMATION RECORDING MEDIUM MANUFACTURING METHOD

Abstract

A concave/convex pattern forming method which is capable of forming a concave/convex pattern on a substrate with high accuracy without causing deformation or faulty transfer of the concave/convex pattern. A concave/convex pattern is formed on an preform by pressing a stamper having a stamper-side concave/convex pattern formed thereon against a resin layer on the preform, thereby transferring the stamper-side concave/convex pattern to the resin layer. The resin layer is formed by coating the preform with a mixed resin material which is prepared by mixing a first resin material having a glass transition is temperature lower than a temperature of the resin layer during pressing of the stamper against the resin layer, and a second resin material having a glass transition temperature higher than the temperature of the resin layer during the pressing of the stamper against the resin layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention will be explained in more detail below with reference to the attached drawings, wherein:

FIG. 1 is a cross-sectional view of a magnetic disk;

FIG. 2 is a cross-sectional view of a stamper;

FIG. 3 is a cross-sectional view of a preform in a state in which a resin layer is formed on a recording layer;

FIG. 4 is a cross-sectional view showing a state where the stamper is pressed against the resin layer on the preform;

FIG. 5 is a cross-sectional view of the preform in a state in which the stamper is removed from the resin layer in the state as shown in FIG. 4;

FIG. 6 is a diagram useful in explaining easiness of pushing the stamper into each of resin layers of Examples 1 to 4 and Comparative Examples 1 and 2, and stability of the concave/convex shape of a concave/convex pattern transferred to each resin layer;

FIG. 7 is a diagram useful in explaining easiness of pushing the stamper into each of resin layers of Examples 1 and 5 to 12 and Comparative Examples 3 and 4, and stability of the concave/convex shape of a concave/convex pattern transferred to each resin layer;

FIG. 8 is a diagram useful in explaining easiness of pushing the stamper into each of resin layers of Examples 2 and 13 to 20 and Comparative Examples 4 and 5, and stability of the concave/convex shape of a concave/convex pattern transferred to each resin layer;

FIG. 9 shows a figure-substitute photograph of a surface of a resin layer, in which a concave/convex pattern (data track pattern) is formed with the occurrence of faulty transfer caused by an insufficient pushing amount of convex portions of the stamper;

FIG. 10 shows a figure-substitute photograph of a surface of a resin layer, in which a concave/convex pattern (data track pattern) is formed without the occurrence of faulty transfer;

FIG. 11 shows a figure-substitute photograph of a surface of a resin layer in a state in which a concave/convex pattern formed on the surface is largely deformed;

FIG. 12 shows a figure-substitute photograph of a surface of a resin layer in a state in which a concave/convex pattern formed on the surface is deformed to such a slight degree that will permit the concave/convex pattern to be used as a mask pattern;

FIG. 13 shows a figure-substitute photograph of a surface of a resin layer in a state in which a concave/convex pattern formed on the surface is deformed very slightly; and

FIG. 14 shows a figure-substitute photograph, of a surface of a resin layer in a state in which a concave/convex pattern formed on the surface is hardly deformed.

Claims

1. A concave/convex pattern forming method comprising pressing a stamper having a stamper-side concave/convex pattern formed thereon against a resin layer on a substrate, thereby transferring the stamper-side concave/convex pattern to the resin layer to form a concave/convex pattern on the substrate, wherein the resin layer is formed by coating the substrate with a mixed resin material which is prepared by mixing a first resin material having a glass transition temperature lower than a temperature of the resin layer during pressing of the stamper against the resin layer, and a second resin material having a glass transition temperature higher than the temperature of the resin layer during the pressing of the stamper against the resin layer.

2. An information recording medium manufacturing method comprising using the concave/convex pattern formed on the substrate according to the concave/convex pattern forming method according to claim 1 to manufacture an information recording medium.