Polystyrene as a resist for making patterned media

• US 20030104316A1
• Filed: 03/29/2002
• Published: 06/05/2003
• Est. Priority Date: 11/30/2001
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Deeman, Neil, Wago, Koichi, Wang, HongYing, Kurataka, Nobuo
• Granted Patent: US 6,838,227 B2
• Time in Patent Office: Days
• US Class Current: 430/296
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G03F 7/0002 Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping
• CPC Class Codes: G11B 5/7379 Seed layer, e.g. at least one non-magnetic layer is specifically adapted as a seed or seeding layer
• CPC Class Codes: G11B 5/74 Record carriers characterised by the form, e.g. sheet shaped to wrap around a drum
• CPC Class Codes: G11B 5/743 Patterned record carriers, wherein the magnetic recording layer is patterned into magnetic isolated data islands, e.g. discrete tracks
• CPC Class Codes: G11B 5/82 Disk carriers
• CPC Class Codes: G11B 5/855 Coating only part of a support with a magnetic layer
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10T 428/249921 Web or sheet containing structurally defined element or component
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

A system and method for forming servo patterns on magnetic media is disclosed. A magnetic film coated with a layer of polystyrene is stamped with a nickel stamper reproducing the negative image of the stamped pattern on the polystyrene. Ions are then accelerated towards the surface of the polystyrene, which stopps the ions in the areas where the polystyrene is thick and allows the ions to penetrate through to the magnetic layer in the areas where the polystyrene is thin. The ions, which penetrate through to the magnetic layer, interact with the magnetic layer altering the magnetic layer'"'"'s structure reducing its coercivity (Hc) and remnant moment (Mrt). This reproduces the stamped polystyrene pattern on the magnetic layer. The polystyrene is then removed by oxygen plasma etching the surface leaving behind a patterned magnetic media.

Claims

1. A method of making patterned medium, comprising the steps of:

using a patterned thermoplastic polymer having a pattern, deposited over a magnetic medium, as a mask; and

exposing said patterned thermoplastic polymer to ions which penetrate the polymer according to said pattern and patterning a magnetic layer.

2. The method of claim 1 wherein said thermoplastic polymer is polystyrene.

3. The method of claim 1 wherein said thermoplastic polymer is styrene co-polymers.

4. The method of claim 1 wherein the step of using a patterned thermoplastic polymer having a pattern further comprises depositing a polymer over a magnetic layer and patterning said polymer with said pattern with a stamper.

5. A method for patterning magnetic medium, comprising the steps of:

coating a thermoplastic polymer material on a magnetic medium to make a resist film;

patterning said thermoplastic polymer layer according to a predetermined pattern;

altering magnetic properties of said magnetic medium according to said pattern by exposing the thermoplastic polymer, after patterning, to ions which penetrate said thermoplastic polymer layer according to said pattern; and

removing said thermoplastic polymer layer leaving said pattern on said magnetic medium.

6. The method of claim 5 where in said thermoplastic polymer is polystyrene.

7. The method of claim 5 where in said thermoplastic polymer is styrene co-polymers.

8. The method of claim 5 wherein the step of patterning further includes stamping the thermoplastic polymer with a stamper having a negative image of said pattern.

9. The method of claim 5 wherein said ions is a molecule.

10. The method of claim 5 where in said magnetic medium comprises;

a substrate;

a seed layer for controlling growth of additional layers;

a magnetic layer for storing data; and

a protective overcoat.

11. The method of claim 5 where in said magnetic medium is a magnetic layer.

12. A system for making patterned magnetic medium, comprising;

a substrate;

a magnetic layer deposited on said substrate for patterning according to a pattern; and

a thermoplastic polymer layer deposited over said magnetic layer, said thermoplastic polymer layer having said pattern acting as a mask that blocks incoming ions according to said pattern.

13. The system of claim 12 wherein said thermoplastic polymer layer is polystyrene.

14. The system of claim 12 wherein said thermoplastic polymer layer is styrene co-polymers.

15. The system of claim 12 wherein said magnetic layer is a plurality of magnetic layers.

16. The system of claim 12 further comprising a protective overcoat that is deposited between said magnetic layer and said thermoplastic polymer layer.

17. The system of claim 12 further comprising a seed layer that is deposited between said substrate and said magnetic layer.

18. The system of claim 17 wherein said seed layer comprises chromium.

19. A thermoplastic resist used for nano-imprint lithography and consequent ion implantation, comprising a mixture of polystyrene and a solvent.

20. The system of claim 19 wherein said solvent is selected from the group consisting of methoxybenzene, benzene, toluene and metaletherketone.

21. A method for patterning magnetic medium, comprising:

means for coating a thermoplastic polymer layer material on a magnetic medium to make a resist film;

means for patterning said thermoplastic polymer layer according to a predetermined pattern;

means for altering magnetic properties of said magnetic medium according to said pattern by exposing a patterned polymer surface to a plurality of ions which penetrate said polymer layer according to said pattern; and

means for removing said thermoplastic polymer layer leaving said pattern on said magnetic medium.

22. The method for patterning magnetic medium of claim 21 wherein said means for patterning said thermoplastic polymer layer further includes stamping said predetermined patterned with a stamper.