US5146299A
Expired / Lapsed
US
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Ferroelectric thin film material, method of deposition, and devices using same
Assignee: Micron Technology Inc
•
Filing: 1990-03-02
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Granted: 1992-09-08
•
Expires: 2010-03-02
Abstract
Abstract A ferroelectric device that comprises a polarizing thin film of BaMF4 deposited on a substrate. Ba is barium, M is one of the metals of the group consisting of iron (FE), manganese (Mn), cobolt (Co), nickel (Ni), magnesium (Mg), and zinc (Zn). The substrate is silicon, sapphire, or gallium arsenide. A non-volatile NDRO and DRO memory cell and methods for depositing the thin film. A method of depositing bismuth titanate on a substrate are described.
Inventors
- 👤 Donald R. Lampe
- 👤 Samar Sinharoy
- 👤 Shu Y. Wu
- 👤 Harry Buhay
- 👤 Maurice H. Francombe
- 👤 S. Visvanathan Krishnaswamy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:12
CPC Classifications
H; H10; H10B; H10B53/00
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
72 words
A ferroelectric non-volatile storage device, comprising: a semiconductor substrate; a thin film of a ferroelectric solid solution of metal halides composed of a mixture of divalent salts deposited on the substrate, the thin film exhibiting ferroelectric hysteresis in the range of about -55 degrees C. to 150 degrees C.; and means electrically coupled to the thin film and the substrate for applying a predetermined voltage for reversing polarization of the thin film.
Claim 2
Dependent Claim
72 words
A ferroelectric non-volatile storage device, comprising: a semiconductor substrate; a thin film of a ferroelectric solid solution of metal halides composed of a mixture of divalent salts deposited on the substrate, the thin film exhibiting ferroelectric hysteresis in the range of about -55 degrees C. to 150 degrees C.; and means electrically coupled to the thin film and the substrate for applying a predetermined voltage for reversing polarization of the thin film.
Claim 3
Dependent Claim
18 words
The storage device of claim 1 further comprising a buffer layer between the thin film and the substrate.
Claim 4
Dependent Claim
22 words
The storage device of claim 1 wherein the thin film is composed of a mixture of divalent salts having no oxygen content.
Claim 5
Dependent Claim
48 words
The storage device of claim 1 wherein the divalent salts is a compound having the formula BaMF 4 where Ba is barium, F is fluoride, and M is selected from the group consisting of manganese (Mn), iron (Fe), nickel (Ni), cobalt (Co), magnesium (Mg), and zinc (Zn) .
Claim 6
Dependent Claim
72 words
A ferroelectric non-volatile storage device comprising: a substrate; a thin film including a compound having the formula Bi 4 Ti 3 O 12 exhibiting ferroelectric hysteresis in the temperature range of about -55 degrees C. to 150 degrees C.; a buffer layer between the thin film and the substrate, and means electrically coupled to the thin film and the substrate for applying a predetermined voltage for reversing polarization of the thin film.
Claim 7
Dependent Claim
72 words
A ferroelectric non-volatile storage device comprising: a substrate; a thin film including a compound having the formula Bi 4 Ti 3 O 12 exhibiting ferroelectric hysteresis in the temperature range of about -55 degrees C. to 150 degrees C.; a buffer layer between the thin film and the substrate, and means electrically coupled to the thin film and the substrate for applying a predetermined voltage for reversing polarization of the thin film.
Claim 8
Dependent Claim
42 words
The storage device of claim 4 wherein the thin film is composed of a seed layer portion in engagement with a surface of the substrate composed of a source material selected from the group consisting of Ba 2 and MF 2 .
Claim 9
Dependent Claim
27 words
The storage device of claim 1 wherein the substrate is composed of material selected from the group consisting of silicon, SOI (semiconductor On Insulator), and gallium arsenide.
Claim 10
Dependent Claim
28 words
The storage device of claim 4 wherein the thin film is composed of a seed layer portion of MF 2 in engagement with the surface of the substrate.
Claim 11
Dependent Claim
21 words
The storage device of claim 4 wherein the thin film is an interdiffused lattice of BaF 2 and MF 2 .
Claim 12
Dependent Claim
19 words
The storage device of claim 4 wherein the thin film is coincidentally deposited BaF 2 and MF 2 .
Claim 13
Dependent Claim
29 words
The storage device of claim 4 wherein the thin film is a reaction of a metal organic compound containing M and liquid hydrogen fluorine mixed with BaF 2 .
Claim 14
Dependent Claim
27 words
The storage device of claim 11 wherein the metal organic compound is selected from the group consisting of a metal alkoxide, a metal β-diketonate, and a metallocene.
Claim 15
Dependent Claim
18 words
The storage device of claim 2, wherein the buffer layer includes Bi 4 Ti 3 O 12 .
Claim 16
Dependent Claim
18 words
The storage device of claim 2 wherein the buffer layer is either CaF 2 or BaF 2 .
Claim 17
Dependent Claim
26 words
The storage device of claim 2 wherein the buffer layer is an alkaline-fluoride in the range of about 5-100 Angstroms thick incorporated into the thin film.
Claim 18
Dependent Claim
20 words
The storage device of claim 2 wherein the buffer layer is an epitaxial intermetallic compound of either titanium or bismuth-titanium.
Claim 19
Dependent Claim
118 words
A ferroelectric non-volatile field effect transistor, comprising: a semiconductor substrate of one type of conductivity; spaced regions of the opposite type conductivity formed in a surface of the substrate; a thin film of a ferroelectric solid solution of metal halides composed of a mixture of divalent salts spanning the space between said regions, the thin film exhibiting ferroelectric hysteresis in the range of about -55 degrees C. to 150 degrees C., and being processable at temperatures non injurious to the substrate and spaced regions, and being disposed without cross contamination between the film and the substrate; and means for establishing a potential across the thin film and the substrate for effecting the spontaneous polarization of the thin film.
Claim 20
Dependent Claim
118 words
A ferroelectric non-volatile field effect transistor, comprising: a semiconductor substrate of one type of conductivity; spaced regions of the opposite type conductivity formed in a surface of the substrate; a thin film of a ferroelectric solid solution of metal halides composed of a mixture of divalent salts spanning the space between said regions, the thin film exhibiting ferroelectric hysteresis in the range of about -55 degrees C. to 150 degrees C., and being processable at temperatures non injurious to the substrate and spaced regions, and being disposed without cross contamination between the film and the substrate; and means for establishing a potential across the thin film and the substrate for effecting the spontaneous polarization of the thin film.
Claim 21
Dependent Claim
40 words
The device of claim 17 further comprising a first buffer layer between the thin film and the substrate; a second buffer layer overlaying the thin film; and wherein the potential establishing means includes a conductor overlying the second buffer layer.
Claim 22
Dependent Claim
21 words
The device of claim 17 wherein the thin film is composed of a mixture of divalent salts having no oxygen content.
Claim 23
Dependent Claim
48 words
The device of claim 17 wherein the mixture of divalent salts is a compound having the formula BaMF 4 where Ba is barium, F is fluorine, and M is selected from the group consisting of manganese (Mn), iron (Fe), nickel (Ni], cobalt (Co), magnesium (Mg), and zinc (Zn).
Claim 24
Dependent Claim
115 words
A ferroelectric non-volatile field effect transistor, comprising: a semiconductor substrate of one type of conductivity; spaced regions of the opposite type conductivity formed in a surface of the substrate; a thin film of a compound having the formula Bi 4 Ti 3 O 12 spanning the space between said regions, the thin film exhibiting ferroelectric hysteresis in the range of about -55 degrees C. to 150 degrees C., and being processable at temperatures non injurious to the substrate and spaced regions, and being disposed without cross contamination between the film and the substrate; and means for establishing a potential across the thin film and the substrate for effecting the spontaneous polarization of the thin film.
Claim 25
Dependent Claim
115 words
A ferroelectric non-volatile field effect transistor, comprising: a semiconductor substrate of one type of conductivity; spaced regions of the opposite type conductivity formed in a surface of the substrate; a thin film of a compound having the formula Bi 4 Ti 3 O 12 spanning the space between said regions, the thin film exhibiting ferroelectric hysteresis in the range of about -55 degrees C. to 150 degrees C., and being processable at temperatures non injurious to the substrate and spaced regions, and being disposed without cross contamination between the film and the substrate; and means for establishing a potential across the thin film and the substrate for effecting the spontaneous polarization of the thin film.
Claim 26
Dependent Claim
41 words
The device of claim 20 wherein the thin film is composed of a seed layer portion in engagement with a surface of the substrate composed of a source material selected from the group consisting of Ba 2 and MF 2 .
Claim 27
Dependent Claim
26 words
The device of claim 17 wherein the substrate is composed of material selected from the group consisting of silicon, semiconductor on insulator (SOI), and gallium arsenide.
Claim 28
Dependent Claim
27 words
The device of claim 20 wherein the thin film is composed of a seed layer portion of MF 2 in engagement with the surface of the substrate.
Claim 29
Dependent Claim
19 words
The device of claim 20 wherein the thin film is an interdiffused lattice of Ba and MF 2 .
Claim 30
Dependent Claim
17 words
The device of claim 20 wherein the thin film is coincidentally deposited Ba and MF 2 .
Claim 31
Dependent Claim
28 words
The device of claim 20 wherein the thin film is a reaction of a metal organic compound containing M and liquid hydrogen fluoride mixed with BaF 2 .
Claim 32
Dependent Claim
26 words
The device of claim 27 wherein the metal organic compound is selected from the group consisting of a metal alkoxide, a metal β-diketonate, and a metallocene.
Claim 33
Dependent Claim
18 words
The device of claim 18 wherein the first buffer layer includes Bi 4 Ti 3 O 12 .
Claim 34
Dependent Claim
18 words
The device of claim 18 wherein the first buffer layer is either CaF 2 or BaF 2 .
Claim 35
Dependent Claim
26 words
The device of claim 18 wherein the first buffer layer is an alkaline-fluoride in the range of about 5-100 Angstroms thick incorporated into the thin film.
Claim 36
Dependent Claim
20 words
The device of claim 18 wherein the first buffer layer is an epitaxial intermetallic compound of either titanium or bismuth-titanium.
Claim 37
Dependent Claim
26 words
The storage device of claim 1 wherein the electrical means include a gate, and further comprises a buffer layer between the thin film and the gate.
Claim 38
Dependent Claim
19 words
The storage device of claim 33 further comprising a second buffer layer between the thin film and the substrate.
Claim 39
Dependent Claim
74 words
A ferroelectric non-volatile storage device comprising: a substrate; a thin film of a ferroelectric solid solution exhibiting ferroelectric hysteresis in the temperature range of about -55 degrees C. to 150 degrees C.; a buffer layer in the range of approximately 5-100 Angstroms in thickness between the thin film and the substrate; and means electrically coupled to the thin film and the substrate for applying a predetermined voltage for reversing polarization of the thin film.
Claim 40
Dependent Claim
74 words
A ferroelectric non-volatile storage device comprising: a substrate; a thin film of a ferroelectric solid solution exhibiting ferroelectric hysteresis in the temperature range of about -55 degrees C. to 150 degrees C.; a buffer layer in the range of approximately 5-100 Angstroms in thickness between the thin film and the substrate; and means electrically coupled to the thin film and the substrate for applying a predetermined voltage for reversing polarization of the thin film.
Claim 41
Dependent Claim
11 words
The storage device of claim 35 wherein the substrate comprises sapphire.
Claim 42
Dependent Claim
127 words
A ferroelectric non-volatile field effect transistor, comprising: a semiconductor substrate of one type of conductivity; spaced regions of the opposite type conductivity formed in a surface of the substrate; a thin film of a ferroelectric solid solution spanning the space between said regions, the thin film exhibiting ferroelectric hysteresis in the range of about -55 degrees C. to 150 degrees C., and being processable at temperatures non injurious to the substrate and spaced regions, and being disposed without cross contamination between the film and the substrate; a buffer layer in the range of about 5-100 Angstroms in thickness between the thin film and the substrate; and means for establishing a potential across the thin film and the substrate for effecting the spontaneous polarization of the thin film.
Claim 43
Dependent Claim
127 words
A ferroelectric non-volatile field effect transistor, comprising: a semiconductor substrate of one type of conductivity; spaced regions of the opposite type conductivity formed in a surface of the substrate; a thin film of a ferroelectric solid solution spanning the space between said regions, the thin film exhibiting ferroelectric hysteresis in the range of about -55 degrees C. to 150 degrees C., and being processable at temperatures non injurious to the substrate and spaced regions, and being disposed without cross contamination between the film and the substrate; a buffer layer in the range of about 5-100 Angstroms in thickness between the thin film and the substrate; and means for establishing a potential across the thin film and the substrate for effecting the spontaneous polarization of the thin film.
Claim 44
Dependent Claim
11 words
The storage device of claim 37 wherein the substrate comprises sapphire.
Claim 45
Dependent Claim
26 words
The storage device of claim 5 wherein the buffer layer is an alkaline-fluoride in the range of about 5-100 Angstroms thick incorporated into the thin film.
Claim 46
Dependent Claim
18 words
The storage device of claim 35 wherein the buffer layer is an alkaline-fluoride incorporated into the thin film.
Claim 47
Dependent Claim
18 words
The storage device of claim 37 wherein the buffer layer is an alkaline-fluoride incorporated into the thin film.
References Cited (Backward Citations)
US3710352A
Cited
US3774174A
Cited
US3808674A
Cited
US3832700A
Cited
US4161038A
Cited
JPS62185376A
Cited
US4860254A
Cited
US4772985A
Cited
JPS6466899A
Cited
US4897374A
Cited
US4888630A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1995-09-08 | 1996-03-09 | 1996-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-08 | 2000-03-09 | 2000-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-08 | 2004-03-09 | 2004-09-08 | $7700.00 | Window Closed / Lapsed |