US5677226A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making integrated circuits
Assignee: NEC Electronics Corp
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Filing: 1995-07-17
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Granted: 1997-10-14
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Expires: 2015-07-17
Abstract
Abstract The invention provides an integrated circuit including a capacitor provided with a silicon nitride film formed on a lower electrode of a polycrystalline silicon film by a rapid thermal nitridation method, a BaTiO 3 film formed on the silicon nitride film and an upper electrode. The above capacitor structure can prevent the formation of a silicon oxide layer at the interface between the polycrystalline silicon film and the BaTiO 3 , and thus has high capacitance.
Inventors
- 👤 Akihiko Ishitani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:32
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/682
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
98 words
A method of forming an integrated circuit, comprising the steps of: forming a lower electrode including a polycrystalline silicon film on a semiconductor substrate; forming a multilayered insulating film including a silicon nitride film at an interface between a natural oxide film on said polycrystalline silicon film and said polycrystalline silicon film; wet etching to remove said natural oxide film; forming ABO 3 type composite oxide films on said silicon nitride film, wherein A is Sr, Ba or Li; B is Ti or Nb; and O is oxygen; and forming an upper electrode on said multilayered insulating film.
Claim 2
Independent Claim
98 words
A method of forming an integrated circuit, comprising the steps of: forming a lower electrode including a polycrystalline silicon film on a semiconductor substrate; forming a multilayered insulating film including a silicon nitride film at an interface between a natural oxide film on said polycrystalline silicon film and said polycrystalline silicon film; wet etching to remove said natural oxide film; forming ABO 3 type composite oxide films on said silicon nitride film, wherein A is Sr, Ba or Li; B is Ti or Nb; and O is oxygen; and forming an upper electrode on said multilayered insulating film.
Claim 3
Dependent Claim
23 words
A method of forming an integrated circuit according to claim 1, wherein said multilayered insulating film is formed by nitriding said lower electrode.
Claim 4
Dependent Claim
28 words
A method of forming an integrated circuit according to claim 1, wherein said multilayered insulating film is formed by nitriding said lower electrode in an atmosphere of ammonia.
Claim 5
Dependent Claim
26 words
A method of forming an integrated circuit according to claim 1, wherein said multilayered insulating film is formed from said lower electrode by lamp annealing process.
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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) | 2000-10-13 | 2001-04-14 | 2001-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-13 | 2005-04-14 | 2005-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-13 | 2009-04-14 | 2009-10-14 | $7700.00 | Window Closed / Lapsed |