US4460412A
Expired / Lapsed
US
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Method of making magnetic bubble memory device by implanting hydrogen ions and annealing
Assignee: Hitachi Ltd
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Filing: 1982-04-12
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Granted: 1984-07-17
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Expires: 2002-04-12
Abstract
Abstract A method of implanting a magnetic garnet film with ions is disclosed in which a covering film is provided on a monocrystalline magnetic garnet film for magnetic bubbles, and hydrogen ions are implanted in a desired portion of a surface region in the magnetic garnet film through the covering film. According to this method, it is possible to form an ion-implanted layer in which the ion concentration distribution in the direction of depth is uniform, and moreover the inplane anisotropy field in the ion-implanted layer decreases only a little with time in an annealing process.
Inventors
- 👤 Ryo Imura
- 👤 Tadashi Ikeda
- 👤 Ryo Suzuki
- 👤 Nagatugu Koiso
- 👤 Teruaki Takeuchi
- 👤 Hiroshi Umezaki
- 👤 Yutaka Sugita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:25
CPC Classifications
H; H01; H01F; H01F10/00; H01F10/08; H01F10/10; H01F10/18; H01F10/20; H01F10/24; H01F41/00; H01F41/14; H01F41/32; H01F41/34
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
132 words
A method of implanting a magnetic garnet film with ions to provide an ion-implanted layer in a magnetic bubble memory device comprising the steps of: providing a covering film on a magnetic garnet film for magnetic bubbles, said film comprising a material that scatters hydrogen ions and that prevents hydrogen ion evaporation; implanting hydrogen ions in a desired portion of a surface region in said magnetic garnet film through said covering film to form said ion-implanted layer at said desired portion of said surface region, the direction of travel of said ions being irregularly changed as the ions pass through said covering layer, and heating the ion-implanted layer to an annealing temperature to cause uniform distribution of the implanted ions in said ion-implanted layer of said garnet film under said covering layer.
Claim 2
Independent Claim
132 words
A method of implanting a magnetic garnet film with ions to provide an ion-implanted layer in a magnetic bubble memory device comprising the steps of: providing a covering film on a magnetic garnet film for magnetic bubbles, said film comprising a material that scatters hydrogen ions and that prevents hydrogen ion evaporation; implanting hydrogen ions in a desired portion of a surface region in said magnetic garnet film through said covering film to form said ion-implanted layer at said desired portion of said surface region, the direction of travel of said ions being irregularly changed as the ions pass through said covering layer, and heating the ion-implanted layer to an annealing temperature to cause uniform distribution of the implanted ions in said ion-implanted layer of said garnet film under said covering layer.
Claim 3
Dependent Claim
28 words
A method according to claim 1, wherein said covering film is one selected from a group consisting of an insulating film, a semiconductor film and a conductor film.
Claim 4
Dependent Claim
56 words
A method according to claim 2, wherein said insulating film is formed of at least one selected from a group consisting of an SiO 2 film, a TiO 2 film, an SiO film, an Al 2 O 3 film, an Si 3 N 4 film, a Cr 3 O 4 film and a phosphosilicate glass film.
Claim 5
Dependent Claim
25 words
A method according to claim 2 or 3, wherein the thickness of said insulating film substantially lies in a range from 500 to 6000 Å.
Claim 6
Dependent Claim
42 words
A method according to claim 2, wherein said semiconductor film and conductor film are selected from a group consisting of a polycrystalline silicon film, an amorphous silicon film, an Au film, an Mo film, a Cr film and an Au-Cu alloy film.
Claim 7
Dependent Claim
28 words
A method according to claim 2 or 5, wherein the thickness of said semiconductor film and conductor film substantially lies in a range from 500 to 3000 Å.
Claim 8
Dependent Claim
23 words
A method according to claim 1, wherein said implanting of hydrogen ions is performed with acceleration energy between 25 KeV and 400 KeV.
Claim 9
Independent Claim
108 words
A method of making magnetic bubble memory devices comprising the steps of: forming a covering film, capable of ion scattering and ion evaporation preventing, on a magnetic garnet film for magnetic bubbles; implanting hydrogen ions in a desired portion of a surface region of said magnetic garnet film through said covering film to form an ion-implanted layer in said desired portion, the travelling direction of said implanted ions being irregularly changed during their passage through said covering film; and depositing thereafter, a pattern of a permalloy film on said garnet film, said permalloy film pattern depositing step including heating at least said garnet film having been partly ion-implanted.
Claim 10
Independent Claim
108 words
A method of making magnetic bubble memory devices comprising the steps of: forming a covering film, capable of ion scattering and ion evaporation preventing, on a magnetic garnet film for magnetic bubbles; implanting hydrogen ions in a desired portion of a surface region of said magnetic garnet film through said covering film to form an ion-implanted layer in said desired portion, the travelling direction of said implanted ions being irregularly changed during their passage through said covering film; and depositing thereafter, a pattern of a permalloy film on said garnet film, said permalloy film pattern depositing step including heating at least said garnet film having been partly ion-implanted.
Claim 11
Dependent Claim
38 words
A method according to claim 8, further comprising the step of annealing said ion-implanted garnet film to provide a uniform distribution of the concentration of said implanted ions in said garnet film with said covering film formed thereon.
Claim 12
Dependent Claim
23 words
A method according to claim 9, wherein said annealing step is simultaneously performed by said heating for said permalloy film pattern forming step.
Claim 13
Dependent Claim
22 words
A method according to claim 8, wherein said heating for said permalloy film pattern depositing step is effected at about 350° C.
Claim 14
Dependent Claim
28 words
A method according to claim 8, wherein said covering film is one selected from a group consisting of an insulating film, a semiconductor film and a conductor film.
Claim 15
Dependent Claim
56 words
A method according to claim 12, wherein said insulating film is formed of at least one selected from a group consisting of an SiO 2 film, a TiO 2 film, an SiO film, an Al 2 O 3 film, an Si 3 N 4 film, a Cr 3 O 4 film and a phosphosilicate glass film.
Claim 16
Dependent Claim
25 words
A method according to claim 12 or 13, wherein the thickness of said insulating film substantially lies in a range from 500 to 6,000 Å.
Claim 17
Dependent Claim
42 words
A method according to claim 12, wherein said semiconductor film and conductor film are selected from a group consisting of a polycrystalline silicon film, an amorphous silicon film, an Au film, an Mo film, a Cr film and an Au-Cr alloy film.
Claim 18
Dependent Claim
28 words
A method according to claim 12 or 15, wherein the thickness of said semiconductor film and conductor film substantially lies in a range from 500 to 3,000 Å.
Claim 19
Dependent Claim
23 words
A method according to claim 8, wherein said implanting of hydrogen ions is performed with acceleration energy between 25 KeV and 400 KeV.
Claim 20
Dependent Claim
21 words
A method according to claim 1, wherein said ion-implanted layer is heated to an annealing temperature of 320° to 350° C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1987-07-17 | 1988-01-16 | 1988-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-17 | 1992-01-16 | 1992-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-17 | 1996-01-16 | 1996-07-17 | $7700.00 | Window Closed / Lapsed |