US5084152A
Expired / Lapsed
US
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Method for preparing high density magnetic recording medium
Assignee: Industrial Technology Research Institute
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Filing: 1990-10-02
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Granted: 1992-01-28
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Expires: 2010-10-02
Abstract
Abstract RF sputtered CoCrTa film deposited on a thin Cr underlayer for longitudinal magnetic recording and the preparation method thereof are disclosed. The film exhibits a (1010) texture which provides a high coercivity of 1190 Oe. The high coercivity is obtained on a 200 A Cr underlayer with a low argon pressure of 4 mtorr and high substrate bias of -100 V.
Inventors
- 👤 Jiang-Ching Lin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:07
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/656; C; C23; C23C; C23C14/00; C23C14/06; C23C14/14; C23C14/16; G11B5/84; G11B5/851
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
104 words
An RF sputtering method for preparing a CoCrTa/Cr magnetic media comprising the steps of: (a) evacuating a sputtering compartment containing a substrate material to a background pressure of 3×10-7 mtorr; (b) passing low pressure argon gas to sputter-etch said substrate material; (c) sputtering a Cr underlayer on said substrate under the conditions of argon pressure: 5 mtorr to 20 mtorr; substrate bias: -100 V; sputtering thickness: 200-800 A; and (d) sputtering a CoCrTa magnetic film on said Cr underlayer under the conditions of argon pressure: 2 mtorr to 20 mtorr; substrate bias: -25 V to -150 V; sputtering thickness: 200 A to 2000 A.
Claim 2
Dependent Claim
104 words
An RF sputtering method for preparing a CoCrTa/Cr magnetic media comprising the steps of: (a) evacuating a sputtering compartment containing a substrate material to a background pressure of 3×10-7 mtorr; (b) passing low pressure argon gas to sputter-etch said substrate material; (c) sputtering a Cr underlayer on said substrate under the conditions of argon pressure: 5 mtorr to 20 mtorr; substrate bias: -100 V; sputtering thickness: 200-800 A; and (d) sputtering a CoCrTa magnetic film on said Cr underlayer under the conditions of argon pressure: 2 mtorr to 20 mtorr; substrate bias: -25 V to -150 V; sputtering thickness: 200 A to 2000 A.
Claim 3
Dependent Claim
21 words
An RF sputtering method as set forth in claim 1, wherein the substrate material is glass or Ni-P treated Al-Mg alloy.
Claim 4
Dependent Claim
33 words
An RF sputtering method as set forth in claim 1, wherein the sputtering of Cr underlayer is carried out at an argon pressure of 10 mtorr and a substrate bias of -100 V.
Claim 5
Dependent Claim
39 words
An RF sputtering method as set forth in claim 1, wherein the sputtering of CoCrTa film is carried out at an argon pressure of 3 mtorr to 5 mtorr and a substrate bias of -100 V to -125 V.
Claim 6
Dependent Claim
22 words
An RF sputtering method as set forth in claim 1, wherein the CoCrTa film thickness is from 600 A to 1000 A.
Claim 7
Dependent Claim
21 words
The method of claim 1 where the Cr underlayer sputtering step is conducted at an argon pressure of about 10 mtorr.
Claim 8
Dependent Claim
33 words
The method of claim 6 where said CoCrTa sputtering step is conducted in an argon pressure of from 3 to 5 mtorr and a substrate bias of from -100 V to -125 V.
Claim 9
Dependent Claim
33 words
The method of claim 1 where said CoCrTa sputtering step is conducted in an argon pressure of from 3 to 5 mtorr and a substrate bias of from -100 V to -125 V.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-01-27 | 1995-07-29 | 1996-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-27 | 1999-07-29 | 2000-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-27 | 2003-07-29 | 2004-01-28 | $7700.00 | Window Closed / Lapsed |