Patent US5316982A successfully refreshed from Google Patents.
US5316982A
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Semiconductor device and method for preparing the same
Assignee: Sharp Corp
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Filing: 1992-05-28
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Granted: 1994-05-31
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Expires: 2012-05-28
Abstract
Abstract A semiconductor device comprising a capacitor having a lower electrode of a Si-containing material, an aluminum oxide film formed on the surface of the lower electrode, a dielectric film of Ta 2 O 5 formed on the aluminum oxide film and an upper electrode provided on the dielectric film.
Inventors
- 👤 Kouji Taniguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:05
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
87 words
A method for preparing a semiconductor device comprising: (i) (a) forming an aluminum or aluminum oxide film on a lower electrode of a Si-containing material, (b) performing a first annealing in a non-oxidative atmosphere whereby oxide film occurring on a surface of the lower electrode is reduced with aluminum or aluminum oxide, (ii) forming a dielectric film of Ta 2 O 5 on the resulting aluminum oxide film, followed by second annealing in an oxidative atmosphere, and then (iii) forming an upper electrode on the dielectric film.
Claim 2
Independent Claim
87 words
A method for preparing a semiconductor device comprising: (i) (a) forming an aluminum or aluminum oxide film on a lower electrode of a Si-containing material, (b) performing a first annealing in a non-oxidative atmosphere whereby oxide film occurring on a surface of the lower electrode is reduced with aluminum or aluminum oxide, (ii) forming a dielectric film of Ta 2 O 5 on the resulting aluminum oxide film, followed by second annealing in an oxidative atmosphere, and then (iii) forming an upper electrode on the dielectric film.
Claim 3
Dependent Claim
51 words
A method for preparing a semiconductor device as set forth in claim 1, wherein the first annealing is carried out at about 300° to 450° C. for about 10 to 100 mins in a non-oxidative atmosphere of N 2 or N 2 /N 2 gas at about 300° to 450° C.
Claim 4
Dependent Claim
55 words
A method for preparing a semiconductor device as set forth in claim 1, wherein the second annealing is carried at about 500° to 800° C. for about 10 to 100 mins in oxygen atmosphere, or at about 300° to 600° C. for about 10 to 100 mins in oxygen or ozone atmosphere applying UV beam.
Claim 5
Dependent Claim
35 words
A method for preparing a semiconductor device as set forth in claim 1, wherein the step of forming the aluminum or aluminum oxide film on a lower electrode is conducted while conducting the first annealing.
Claim 6
Dependent Claim
36 words
A method for preparing a semiconductor device as set froth in claim 1, wherein the step of forming the aluminum or aluminum oxide film on a lower electrode is conducted prior to conducting the first annealing.
Claim 7
Dependent Claim
38 words
A method for preparing a semiconductor device as set forth in claim 1, wherein the aluminum oxide film is formed 10 to 50 Å in thickness and the dielectric film is formed 50 to 250 Å in thickness.
References Cited (Backward Citations)
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JPS5745968A
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US4437139A
Cited
JPS6235562A
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US5079191A
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US4891684A
Cited
US5138432A
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US5142432A
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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) | 1997-05-30 | 1997-11-29 | 1998-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-30 | 2001-11-29 | 2002-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-30 | 2005-11-29 | 2006-05-31 | $7700.00 | Window Closed / Lapsed |