US4400445A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid phase epitaxial growth of garnet films
Assignee: AT&T Inc
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Filing: 1981-11-18
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Granted: 1983-08-23
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Expires: 2001-11-18
Abstract
Abstract The manufacture of magnetic bubble devices typically involves a step of epitaxially depositing a layer of a garnet material on a substrate having suitable lattice parameters, e.g., layers of certain rare earth-iron garnets are conveniently deposited on a gallium-gadolinium garnet substrate. Deposition by liquid epitaxy has been preferred and, in particular, deposition from a melt comprising garnet materials in a PbO--B 2 O 3 flux. According to the invention, garnet layers are epitaxially grown from a melt comprising a PbO--V 2 O 5 flux. Growth from such melt has desirably slow kinetics, resulting in slow deposition as is beneficial especially for the growth of layers on an assembly of substrates. Additional benefits are ease of removal of liquid droplets remaining on a grown film upon removal from the melt, both by spinning and by rinsing.
Inventors
- 👤 George W. Berkstresser
- 👤 Stuart L. Blank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:39
CPC Classifications
C; C30; C30B; C30B19/00; C30B19/02; C30B29/00; C30B29/10; C30B29/16; C30B29/22; C30B29/28
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
143 words
Method for making a magnetic bubble device comprising a layer of a garnet material which is epitaxially deposited on a surface of a supporting substrate, said method comprising (1) heating a preferred melt consisting essentially of said garnet material and a flux material at a temperature corresponding to supercooling of said garnet material, said flux material comprising PbO and V 2 O 5 , PbO being comprised in said flux material in an amount in the range of 67-99 molecular percent, and V 2 O 5 being comprised in said flux material in an amount of at least 50 molecular percent of the molecular percent complementary to the molecular percent PbO, (2) bringing at least said surface of said substrate in contact with said melt, and (3) removing said substrate from contact with said melt upon deposition of said layer on said surface,
Claim 2
Dependent Claim
143 words
Method for making a magnetic bubble device comprising a layer of a garnet material which is epitaxially deposited on a surface of a supporting substrate, said method comprising (1) heating a preferred melt consisting essentially of said garnet material and a flux material at a temperature corresponding to supercooling of said garnet material, said flux material comprising PbO and V 2 O 5 , PbO being comprised in said flux material in an amount in the range of 67-99 molecular percent, and V 2 O 5 being comprised in said flux material in an amount of at least 50 molecular percent of the molecular percent complementary to the molecular percent PbO, (2) bringing at least said surface of said substrate in contact with said melt, and (3) removing said substrate from contact with said melt upon deposition of said layer on said surface,
Claim 3
Dependent Claim
106 words
whereby said deposition is at a desired rate per degree C. of supercooling, said desired rate being less than or equal to 0.53 times a comparison rate, said comparison rate being the rate per degree C. of supercooling when said garnet material is deposited from a comparison melt, said comparison melt consisting essentially of a PbO-B 2 O 3 flux and garnet constituent oxides, the B 2 O 3 :PbO molecular ratio in said comparison melt being 1:15.6, and the molecular ratio of yttrium oxide or its substituents versus iron oxide or its substituents being such that said garnet material is deposited from said comparison melt.
Claim 4
Dependent Claim
106 words
whereby said deposition is at a desired rate per degree C. of supercooling, said desired rate being less than or equal to 0.53 times a comparison rate, said comparison rate being the rate per degree C. of supercooling when said garnet material is deposited from a comparison melt, said comparison melt consisting essentially of a PbO-B 2 O 3 flux and garnet constituent oxides, the B 2 O 3 :PbO molecular ratio in said comparison melt being 1:15.6, and the molecular ratio of yttrium oxide or its substituents versus iron oxide or its substituents being such that said garnet material is deposited from said comparison melt.
Claim 5
Dependent Claim
23 words
Method of claim 1 in which PbO is comprised in said flux material in an amount in the range of 85-95 molecular percent.
Claim 6
Dependent Claim
11 words
Method of claim 1 in which said garnet material is magnetic.
Claim 7
Dependent Claim
25 words
Method of claim 1 in which heating is at a temperature which corresponds to supercooling of said garnet material by at least 3 degrees C.
Claim 8
Dependent Claim
20 words
Method of claim 1 in which said layer has a thickness which is less than or equal to 2 micrometers.
Claim 9
Dependent Claim
16 words
Article of manufacture comprising a magnetic bubble device made according to the method of claim 1.
References Cited (Backward Citations)
US3790405A
Cited
US4165410A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-22 | 1987-02-21 | 1987-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-22 | 1991-02-21 | 1991-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-22 | 1995-02-21 | 1995-08-23 | $7700.00 | Window Closed / Lapsed |