MASTER INFORMATION CARRIER AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To record specified digital information signals in many magnetic recording media by forming ferromagnetic thin films in a plurality of recesses on one principal plane of a nonmagnetic material substrate in such a manner that the side faces of the recess are separated from the side faces of the ferromagnetic material. SOLUTION: A plurality of recesses 11 are formed in a substrate 10b on the principal plane of a master information medium, and ferromagnetic thin films 10c are formed in the recesses 11. The side faces 12 of the recess 11 are separated from the side faces 13 of the ferromagnetic thin film 10c so that a gap is present between the side faces 12 and the side faces 13. The distance L1 between the side faces 12 and the side faces 13 on the surface of the substrate 10b is preferably >=5% and <=20% of the width L2 of the recess 11 on the opening surface. By specifying the distance L1 to be >=5% of the width L2, stress generating in the master information medium 10 can be sufficiently relaxed when the master is tightly in contact with a magnetic recording medium to transfer and record the digital information signals.