US3850690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
METHOD OF MAKING MnGaGe FILMS
Assignee: International Business Machines Corp
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Filing: 1973-02-23
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Granted: 1974-11-26
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Expires: 1993-02-23
Abstract
Abstract A method of making ferromagnetic films of MnGaGe upon a substrate, the films crystallizing in the tetragonal structure and having a grain size of less than one-half micron, made by the method of depositing a first layer of either manganese, or gallium and germanium upon a heated substrate, followed by the deposition of the remaining material upon the first layer, and annealing the deposited layers at a desired temperature until a homogeneous composition is achieved, and then cooling of the film-substrate combination. In this manner, with appropriately chosen temperatures, films having a grain size of less than onehalf micron and being particularly usable for storage applications may be fabricated.
Inventors
- 👤 K Lee
- 👤 J Suits
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:04
CPC Classifications
C; C23; C23C; C23C26/00; H; H01; H01F; H01F10/00; H01F10/08; H01F10/10; H01F10/12; H01F10/26; H01F10/265; H01F41/00; H01F41/14
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
124 words
A METHOD OF MAKING A FINE GRAIN FERROMAGNETIC FILM OF MNGAGE CRYSTALLIZING IN THE TETRAGONAL STRUCTURE UPON A SUBSTRATE COMPRISING THE STEP OF: DEPOSITION A LAYER OF MN AND A LAYER OF (GA + GE) IN THE DESIRED COMPOSITIONAL AMOUNT BASED ON THE FINAL DESIRED COMPOSITION IN AN DESIRED ORDER UPON A SUBSTRATE MAINTAINED AT A TEMPERATURE BETWEEN SUBSTANTIALLY 150*C TO 250*C AS A FIRST LAYER AND A SECOND LAYER UPON SAID FIRST LAYER; ANNEALING THE SUPERIMPOSED DEPOSITED LAYERS AT A TENPERATURE BETWEEN SUBSTANTIALLY 200*C AND 475*C UNTIL A HOMOGENEOUS COMPOSITION IS ACHIEVED; AND COOLING THE FILM-SUBSTRATE COMBINATION, WHEREBY A FERROMAGNETIC FILM OF MAGAGE CRYSTALLIZING IN THE TETRAGONAL STRUCTURE AND HAVING A GRAIN SIZE OF LESS THAN 0.5 MICRON IS FORMED UPON THE SUBSTRATE.
Claim 2
Independent Claim
124 words
A METHOD OF MAKING A FINE GRAIN FERROMAGNETIC FILM OF MNGAGE CRYSTALLIZING IN THE TETRAGONAL STRUCTURE UPON A SUBSTRATE COMPRISING THE STEP OF: DEPOSITION A LAYER OF MN AND A LAYER OF (GA + GE) IN THE DESIRED COMPOSITIONAL AMOUNT BASED ON THE FINAL DESIRED COMPOSITION IN AN DESIRED ORDER UPON A SUBSTRATE MAINTAINED AT A TEMPERATURE BETWEEN SUBSTANTIALLY 150*C TO 250*C AS A FIRST LAYER AND A SECOND LAYER UPON SAID FIRST LAYER; ANNEALING THE SUPERIMPOSED DEPOSITED LAYERS AT A TENPERATURE BETWEEN SUBSTANTIALLY 200*C AND 475*C UNTIL A HOMOGENEOUS COMPOSITION IS ACHIEVED; AND COOLING THE FILM-SUBSTRATE COMBINATION, WHEREBY A FERROMAGNETIC FILM OF MAGAGE CRYSTALLIZING IN THE TETRAGONAL STRUCTURE AND HAVING A GRAIN SIZE OF LESS THAN 0.5 MICRON IS FORMED UPON THE SUBSTRATE.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein the substrate temperature and MnGaGe compositional amounts are so chosen that the annealing step occurs simultaneously with the deposition of the second layer.
Claim 4
Dependent Claim
17 words
The method of claim 2 wherein the substrate temperature is chosen to be at least substantially 300*C.
Claim 5
Dependent Claim
30 words
The method of claim 1 including depositing additional sets of layers of Mn and (Ga and Ge) as desired while maintaining the desired compositional amount, prior to the annealing step.
Claim 6
Dependent Claim
16 words
The method of claim 1 wherein the layers are deposited by the method of vapor deposition.
Claim 7
Dependent Claim
18 words
The method of claim 1 wherein the Mn, Ga and Ge are each deposited from a separate source.
Claim 8
Dependent Claim
10 words
The method of claim 1 wherein the substrate is non-magnetic.
Claim 9
Dependent Claim
16 words
The method of claim 1 wherein the deposition rate of each layer is at least 1A/second.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |