Magnetic recording media with a surface-oxidized nial sub-seedlayer

• US 6,348,276 B1
• Filed: 08/25/1999
• Issued: 02/19/2002
• Est. Priority Date: 09/25/1998
• Status: Expired due to Fees

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Chen, Qixu, Harkness, Samuel Dacke IV, Leu, Charles, Ranjan, Rajiv Yadav, Wu, Zhong
• Primary Examiner(s): Chen, Vivian
• Assistant Examiner(s): Rickman, Holly C.
• Application Number:
  US09/382,581
• Time in Patent Office: 909 Days
• Field of Search: 428/65.3, 428/694.T, 428/694.TS, 428/900, 204/192.1, 204/192.11, 204/192.15, 204/192.2, 427/533, 427/126.2, 427/129, 427/131
• US Class Current: 428/831
• CPC Class Codes: C23C 14/025 Metallic sublayers
• CPC Class Codes: G11B 5/66 the record carriers consisting of several layers
• CPC Class Codes: G11B 5/7369 Two or more non-magnetic underlayers, e.g. seed layers or barrier layers
• 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 5/73921 Glass or ceramic substrates
• CPC Class Codes: G11B 5/8404 manufacturing base layers

Abstract

Magnetic recording media with high coercivity and low noise, suitable for high density longitudinal recording, are formed with a surface oxidized sub-seedlayer between a non-magnetic substrate and seedlayer. Embodiments include depositing a NiAl sub-seedlayer on a glass or glass-ceramic substrate, oxidizing the surface of the NiAl sub-seedlayer, and then sequentially depositing a NiAl seedlayer, Cr or Cr alloy underlayer, e.g., CrMo, an optional intermediate CoCrTa alloy layer, a magnetic layer, e.g., a Co-alloy magnetic layer, and a protective overcoat, e.g., a carbon-containing protective overcoat.

Claims

1. A magnetic recording medium comprising:

a non-magnetic substrate;

a nickel aluminum (NiAl) sub-seedlayer having an oxidized surface on the non-magnetic substrate;

a NiAl seedlayer on the surface oxidized NiAl sub-seedlayer;

an underlayer on the NiAl seedlayer; and

a magnetic layer on the underlayer.

2. The magnetic recording medium according to claim 1, wherein the underlayer comprises chromium or a chromium alloy and the magnetic layer comprises a cobalt alloy containing chromium.

3. The magnetic recording medium according to claim 2, wherein the underlayer comprises a chromium-molybdenum alloy.

4. The magnetic recording medium according to claim 2, wherein the substrate comprises glass or a glass-ceramic material.

5. The magnetic recording medium according to claim 2, further comprising an intermediate cobalt-chromium-tantalum alloy layer between the underlayer and the magnetic layer.

6. The magnetic recording medium according to claim 1, wherein the NiAl sub-seedlayer with the oxidized surface has a thickness of about 50 Å

to about 1,000 Å

.

7. The magnetic recording medium according to claim 6, wherein the oxidized surface comprises about 10 to about 80 at. % oxygen in a top 50 Å

region after in situ sputter removal of a 40 Å

surface layer.

8. The magnetic recording medium according to claim 7, wherein the surface of the NiAl sub-seedlayer comprises substantially elemental nickel and aluminum present in the form of about 75 at. % aluminum oxide and about 25 at. % substantially elemental aluminum.

9. The magnetic recording medium according to claim 6, wherein the seedlayer has a thickness of about 1000 Å

to about 1,000 Å

.

10. A method of manufacturing a magnetic recording medium, the method comprising:

depositing a nickel aluminum (NiAl) sub-seedlayer on a non-magnetic substrate;

oxidizing the surface of the NiAl sub-seedlayer;

depositing a NiAl seedlayer on the surface oxidized NiAl sub-seedlayer; and

depositing a magnetic layer on the seedlayer.

11. The method according to claim 10, further comprising depositing an underlayer on the NiAl seedlayer and the magnetic layer on the underlayer.

12. The method according to claim 11, comprising depositing a chromium or chromium-alloy layer as the underlayer and depositing an alloy containing cobalt and chromium as the magnetic layer.

13. The method according to claim 12, comprising depositing a chromium-molybdenum alloy layer as the underlayer.

14. The method according to claim 11, comprising depositing the NiAl sub-seedlayer on a glass or glass-ceramic substrate.

15. The method according to claim 11, comprising oxidizing the surface of the NiAl sub-seedlayer:

at a temperature of about 20°

C. to about 300°

C.;

at a pressure of about 0.1 mTorr to about 200 Torr;

in an atmosphere comprising about 1 to about 100 vol. % oxygen, the remainder an inert gas;

for more than about 1 second.

16. The method according to claim 11, comprising oxidizing the surface of the NiAl sub-seedlayer in an atmosphere comprising SO₂, NO₂, N₂O, NO, CO and/or CO₂.

17. The method according to claim 15, comprising oxidizing the surface of the NiAl sub-seedlayer such that the oxidized surface comprises about 10 to about 80 at. % oxygen in a top 50 Å

region after in situ sputter removal of a 40 Å

surface layer.

18. The method according to claim 17, comprising oxidizing the surface of the NiAl sub-seedlayer such the oxidized surface comprises substantially elemental nickel and aluminum present in the form of about 25 at. % substantially elemental aluminum and about 75 at. % aluminum oxide.

19. The method according to claim 12, further comprising depositing an intermediate cobalt-chromium-tantalum layer on the underlayer and the magnetic layer on the intermediate layer.