US4476152A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for production of magnetic bubble memory device
Assignee: Hitachi Ltd
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Filing: 1983-02-09
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Granted: 1984-10-09
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Expires: 2003-02-09
Abstract
Abstract Hydrogen ion is implanted twice or more at different acceleration voltages into desired portions of a magnetic film holding magnetic bubbles to form a magnetic bubble propagation path. This ensures production of an ion-implanted device having a sufficiently large anisotropic magnetic field parallel to the magnetic film and a high Curie temperature.
Inventors
- 👤 Ryo Imura
- 👤 Tadashi Ikeda
- 👤 Norio Ohta
- 👤 Teruaki Takeuchi
- 👤 Yutaka Sugita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:38
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/32; H01F41/34; H01F41/14; H01F41/18; H01F41/186
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
39 words
A method for production of a magnetic bubble memory device comprising: implanting hydrogen ion twice or more at different acceleration voltages into predetermined portions of a magnetic film, and heat treating the magnetic film having hydrogen ion implanted therein.
Claim 2
Independent Claim
39 words
A method for production of a magnetic bubble memory device comprising: implanting hydrogen ion twice or more at different acceleration voltages into predetermined portions of a magnetic film, and heat treating the magnetic film having hydrogen ion implanted therein.
Claim 3
Dependent Claim
35 words
A production method according to claim 1 wherein at least one of the two or more hydrogen ion implantations is carried out at a hydrogen ion dose of about 2.5×10 16 ion/cm 2 or more.
Claim 4
Dependent Claim
27 words
A production method according to claim 1 wherein the hydrogen ion is implanted into a region at a depth of about 1/3 of the magnetic film thickness.
Claim 5
Dependent Claim
27 words
A production method according to claim 2 wherein the hydrogen ion is implanted into a region at a depth of about 1/3 of the magnetic film thickness.
Claim 6
Dependent Claim
39 words
A production method according to claim 3 wherein a maximum acceleration voltage for the ion implantation is selected such that a peak depth of a concentration distribution of the implanted ion reaches about 1/3 of the magnetic film thickness.
Claim 7
Dependent Claim
39 words
A production method according to claim 4 wherein a maximum acceleration voltage for the ion implantation is selected such that a peak depth of a concentration distribution of the implanted ion reaches about 1/3 of the magnetic film thickness.
Claim 8
Dependent Claim
56 words
A production method according to claim 1, wherein said hydrogen ion is H 2 + and H + ions, with said H 2 + ions being implanted at an ion dose of 2.5×10 16 ion/cm 2 or more, and said H + ions being implanted at an ion dose of 5×10 16 ion/cm 2 or more.
Claim 9
Dependent Claim
21 words
A production method according to claim 7, wherein the heat-treating is carried out at a temperature of at least 350° C.
Claim 10
Dependent Claim
22 words
A production method according to claim 1, wherein said hydrogen ion only is ion-implanted into said predetermined portions of a magnetic film.
Claim 11
Independent Claim
63 words
A method for production of a magnetic bubble memory device comprising implanting only hydrogen ion twice or more at different acceleration voltages into predetermined portions of a magnetic film, whereby the Curie temperature Tc of the ion-implanted layer is high as compared with the Curie temperature Tc when implanting at least one of Ne + or He + in combination with hydrogen ion.
Claim 12
Independent Claim
63 words
A method for production of a magnetic bubble memory device comprising implanting only hydrogen ion twice or more at different acceleration voltages into predetermined portions of a magnetic film, whereby the Curie temperature Tc of the ion-implanted layer is high as compared with the Curie temperature Tc when implanting at least one of Ne + or He + in combination with hydrogen ion.
Claim 13
Dependent Claim
13 words
A production method according to claim 10 further comprising heat-treating an ion-implanted device.
Claim 14
Dependent Claim
39 words
A production method according to claim 11 wherein a maximum acceleration voltage for the ion implantation is selected such that a peak depth of a cencentration distribution of the implanted ion reaches about 1/3 of the magnetic film thickness.
Claim 15
Dependent Claim
47 words
A production method according to claim 11, wherein at least one of the two or more hydrogen ion implantations is carried out at a hydrogen ion dose of about 2.5×10 16 ion/cm 2 or more, whereby an ion-implanted device having a very long life can be achieved.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-09 | 1988-04-09 | 1988-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-09 | 1992-04-09 | 1992-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-09 | 1996-04-09 | 1996-10-09 | $7700.00 | Window Closed / Lapsed |