HARD DISK MEDIA WITH PATTERN FOR ALIGNMENT, AND ALIGNMENT METHOD

摘要

PROBLEM TO BE SOLVED: To solve the problem that it is necessary to detect the center and direction of a disk in order to correctly allign the disk to a stage upon a surface inspection in a manufacturing process of a patterned medium, but the direction of the disk can not be detected in the case of the present disk. SOLUTION: A patterned medium 1 has a bit pattern 6 consisting of convex parts 4 of a magnetic material at one side plane or both planes of a non-magnetic substrate 2 having a center hole 3. A diffraction grating pattern 20 is formed at an inner periphery (or outer periphery) of the patterned medium 1 as a pattern for alignment. The diffraction grating pattern 20 is a pattern of a repetition type, and includes a repetition pitch pattern being different from other part at at least one place on a circumference, or includes a part having no pattern. The center and the direction of the disk 1 can be detected by irradiating this diffraction grating pattern with detection light and detecting the diffracted light. COPYRIGHT: (C)2009,JPO&INPIT