US4462881A
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Method of forming a multilayer thin film
Assignee: Hitachi Ltd
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Filing: 1981-11-18
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Granted: 1984-07-31
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Expires: 2001-11-18
Abstract
Abstract A method of forming a multilayer thin film is disclosed in which a second thin conductive film is deposited on a first thin conductive film uninterruptedly after the first thin film has been deposited on a substrate, the first and second films thus formed are processed so as to form a predetermined pattern, the surface of the second thin film is cleaned by ion etching and a third thin conductive film is deposited on the whole surface of the substrate, and then the second and third thin films are processed so as to have a pattern different from the above-mentioned predetermined pattern. In the case where two thin conductive films different in material and pattern from each other are piled on a substrate, the above method can form a perfect interconnection between the two films and can make very small the contact resistance between the two films. Accordingly, the method is fit to form, for example, a barber pole type magnetoresistive element.
Inventors
- 👤 Hiroshi Yamamoto
- 👤 Noboru Shimizu
- 👤 Masahide Suenaga
- 👤 Yukihisa Tsukada
- 👤 Tooru Takeura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:03
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; H; H01; H01F; H01F41/00; H01F41/32; H01F41/34
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
145 words
A method of forming a multilayer thin film comprising the steps of: (i) forming on a predetermined substrate a first thin film made of a predetermined conductive or semiconductive material, and successively forming on said first thin film a second thin film made of a conductive material different from said predetermined conductive or semiconductive material; (ii) processing said first and second thin films to form a predetermined pattern; (iii) cleaning a surface of said second thin film by ion etching, and successively forming on the whole surface of said substrate a third thin film made of a conductive material which is different from said predetermined conductive or semiconductive material for forming said first thin film; and (iv) processing said second and third thin films so that said second and third thin films have a predetermined pattern different from said pattern of said first thin film.
Claim 2
Independent Claim
145 words
A method of forming a multilayer thin film comprising the steps of: (i) forming on a predetermined substrate a first thin film made of a predetermined conductive or semiconductive material, and successively forming on said first thin film a second thin film made of a conductive material different from said predetermined conductive or semiconductive material; (ii) processing said first and second thin films to form a predetermined pattern; (iii) cleaning a surface of said second thin film by ion etching, and successively forming on the whole surface of said substrate a third thin film made of a conductive material which is different from said predetermined conductive or semiconductive material for forming said first thin film; and (iv) processing said second and third thin films so that said second and third thin films have a predetermined pattern different from said pattern of said first thin film.
Claim 3
Dependent Claim
24 words
A method according to claim 1, wherein said first thin film is formed of one of a magnetic conductive material and a semiconductor material.
Claim 4
Dependent Claim
61 words
A method according to claim 1 or 2, wherein each of said second and third films is a film selected from the group consisting of an aluminum film, an aluminum alloy film, a molybdenum film, a tungsten film, a two-layer film of chromium and gold, a two-layer film of molybdenum and gold, and a three-layer film of molybdenum, gold and molybdenum.
Claim 5
Dependent Claim
25 words
A method according to claim 1 or 2, wherein said first thin film and said second thin film are successively formed in an evacuated atmosphere.
Claim 6
Dependent Claim
23 words
A method according to claim 4, wherein said cleaning and said formation of the third film are carried out in an evacuated atmosphere.
Claim 7
Dependent Claim
14 words
A method according to claim 5, wherein said ion etching comprises argon ion sputtering.
Claim 8
Dependent Claim
32 words
A method according to claim 1, wherein during processing of said first and second thin films to form a predetermined pattern in step (ii), a part of the substrate is also exposed.
Claim 9
Dependent Claim
20 words
A method according to claim 7, wherein the first thin film is made of a conductive material which is magnetoresistive.
Claim 10
Dependent Claim
22 words
A method according to claim 1, wherein during said ion etching in step (iii), a part of the substrate is also exposed.
Claim 11
Independent Claim
91 words
A method of forming a magnetoresistive element, comprising the steps of: (i) depositing a thin film of magnetoresistive material on a substrate in an evacuated atmosphere; (ii) successively depositing an auxiliary metal film on said magnetoresistive film in the evacuated atmosphere, without exposing the substrate to external atmosphere; (iii) processing portions of said magnetoresistive and auxiliary metal films to form a predetermined pattern; and (iv) cleaning the surface of the auxiliary metal film and successively depositing a main metal film on the whole surface of said substrate in an evacuated atmosphere.
Claim 12
Independent Claim
91 words
A method of forming a magnetoresistive element, comprising the steps of: (i) depositing a thin film of magnetoresistive material on a substrate in an evacuated atmosphere; (ii) successively depositing an auxiliary metal film on said magnetoresistive film in the evacuated atmosphere, without exposing the substrate to external atmosphere; (iii) processing portions of said magnetoresistive and auxiliary metal films to form a predetermined pattern; and (iv) cleaning the surface of the auxiliary metal film and successively depositing a main metal film on the whole surface of said substrate in an evacuated atmosphere.
Claim 13
Dependent Claim
16 words
A method according to claim 10, wherein said cleaning is carried out by argon ion sputtering.
Claim 14
Dependent Claim
22 words
A method according to claim 10, further comprising the step of patterning said auxiliary and main metal films by an etching process.
Claim 15
Dependent Claim
20 words
A method according to claim 12, wherein said auxiliary and main metal films are made of a same metal material.
Claim 16
Dependent Claim
18 words
A method according to claim 13, wherein said magnetoresistive material is permalloy and said metal material is aluminum.
Claim 17
Dependent Claim
42 words
A method according to claim 10, wherein during step (iii), said portions of said magnetoresistive and auxiliary metal films are selectively removed and during step (iv), a part of the substrate is exposed during cleaning the surface of said auxiliary metal film.
Claim 18
Independent Claim
118 words
A method of forming a magnetoresistive element, comprising the steps of: (i) depositing a thin film of magnetoresistive material on a substrate in an evacuated atmosphere; (ii) successively depositing an auxiliary metal film on said magnetoresistive film in the evacuated atmosphere, without exposing the substrate to the external atmosphere; (iii) processing portions of said auxiliary metal film to form a predetermined pattern and to expose a part of said magnetoresistive film; (iv) cleaning the surface of the auxiliary metal film, and simultaneously etching the exposed part of said magnetoresistive metal film employing said auxiliary metal film as a mask; and (v) successively depositing a main metal film on the whole surface of said substrate in an evacuated atmosphere.
Claim 19
Independent Claim
118 words
A method of forming a magnetoresistive element, comprising the steps of: (i) depositing a thin film of magnetoresistive material on a substrate in an evacuated atmosphere; (ii) successively depositing an auxiliary metal film on said magnetoresistive film in the evacuated atmosphere, without exposing the substrate to the external atmosphere; (iii) processing portions of said auxiliary metal film to form a predetermined pattern and to expose a part of said magnetoresistive film; (iv) cleaning the surface of the auxiliary metal film, and simultaneously etching the exposed part of said magnetoresistive metal film employing said auxiliary metal film as a mask; and (v) successively depositing a main metal film on the whole surface of said substrate in an evacuated atmosphere.
Claim 20
Dependent Claim
22 words
A method according to claim 16, further comprising the step of patterning said auxiliary and main metal films by an etching process.
Claim 21
Dependent Claim
32 words
A method according to claim 16, wherein during step (iii), said portions of said auxiliary metal film are selectively removed together with a part of said thin film of said magnetoresistive material.
Claim 22
Dependent Claim
24 words
A method according to claim 10 or claim 16, wherein subsequently said main metal film is selectively etched along with the auxiliary metal film.
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) | 1987-07-31 | 1988-01-30 | 1988-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-31 | 1992-01-30 | 1992-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-31 | 1996-01-30 | 1996-07-31 | $7700.00 | Window Closed / Lapsed |