Master disk for magnetic transfer, a method of drawing a magnetic transfer pattern, and a magnetic recording medium having a transferred magnetic transfer pattern
View Patent ↗A master disk for magnetic transfer of a reference servo signal in a spiral mode, having a pattern including a plurality of dots groups, which are disposed at different radial positions of the master disk with a first pitch, and correspond to the reference servo signal in the spiral mode. Each of the plurality of dot groups includes a plurality of dots, successively disposed with a second pitch along a circumferential direction of the master disk at a same one of the radial positions. Each of the plurality of dots is of a ferromagnetic material, and has four sides, two opposing sides thereof extending in the circumferential direction, and the other two opposing sides thereof extending in a radial direction of the master disk.
1. A master disk for magnetic transfer of a reference servo signal in a spiral mode, comprising:
a pattern of the magnetic transfer including a plurality of dots groups, disposed at different radial positions of the master disk with a first pitch, and corresponding to the reference servo signal in the spiral mode, each of the plurality of dot groups including a plurality of dots, successively disposed with a second pitch along a circumferential direction of the master disk at a same one of the radial positions, each of the plurality of dots being of a ferromagnetic material, and having four sides, two opposing sides thereof extending in the circumferential direction, the other two opposing sides thereof extending in a radial direction of the master disk.
2. The master disk of claim 1 , wherein each of the plurality of dot groups corresponds to a track of the master disk and has 10 or more dots.
3. A method of drawing a pattern of magnetic transfer on a substrate, comprising:
rotating the substrate, and scanning the substrate, using an electron beam, in a circumferential direction; and
performing blank operations to turn irradiation of the electron beam on and off, so as to draw the pattern of the magnetic transfer including a plurality of dots groups at different radial positions with a first pitch, each of the plurality of dot groups including a plurality of dots, successively disposed with a second pitch along a circumferential direction of the master disk at a same one of the radial positions, each of the plurality of dots having four sides, two opposing sides thereof extending in the circumferential direction, the other two opposing sides thereof extending in a radial direction of the master disk.
4. The method of claim 3 , wherein the scanning is repeated ten times or more for one track on the substrate.