US5013692A
Expired / Lapsed
US
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Process for preparing a silicon nitride insulating film for semiconductor memory device
Assignee: Sharp Corp
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Filing: 1989-12-05
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Granted: 1991-05-07
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Expires: 2009-12-05
Abstract
Abstract A process for preparing an insulating film for semiconductor memory device which comprises forming a silicon nitride film over a substrate by a CVD technique, oxidizing the surface of the silicon nitride film to form a silicon oxide layer over the film, and removing the silicon oxide layer by etching to form an improved silicon nitride film, which is suitably used for the formation of a capacitor of highly integrated memory device.
Inventors
- 👤 Shigeaki Ide
- 👤 Ichiroh Oki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:35
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/65; H10P14/6516; H10P14/6518; H10P14/6519; H10P14/6522; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/01344; H10D64/01346; H10D64/60; H10D64/66; H10D64/68; H10D64/681; H10D64/685; H10D64/693; H10P14/66; H10P14/662; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; H10P14/6322; H10P14/6326; H10P14/6328; H10P14/6334; H10P14/668; H10P14/6681; H10P14/6682; H10P14/69; H10P14/692; H10P14/6921; H10P14/69215; H10P14/694; H10P14/6943; H10P14/69433; Y; Y10; Y10S; Y10S148/00; Y10S148/014; Y10S148/114
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
89 words
A process for preparing an insulating film for a semiconductor memory device which comprises formed a silicon nitride film over a substrate by a CVD technique, oxidizing the surface of the silicon nitride film to form a silicon oxide layer over the silicon nitride film, and removing the silicon oxide layer by etching to form an improved silicon nitride film having a capacitance and dielectric strength suitable for use as an insulating film in a semiconductor memory device, and then forming a conductive layer on the silicon nitride film.
Claim 2
Dependent Claim
89 words
A process for preparing an insulating film for a semiconductor memory device which comprises formed a silicon nitride film over a substrate by a CVD technique, oxidizing the surface of the silicon nitride film to form a silicon oxide layer over the silicon nitride film, and removing the silicon oxide layer by etching to form an improved silicon nitride film having a capacitance and dielectric strength suitable for use as an insulating film in a semiconductor memory device, and then forming a conductive layer on the silicon nitride film.
Claim 3
Dependent Claim
39 words
The process of claim 1 in which the silicon nitride film is formed at a temperature of 600° to 800° C. by using ammonia or nitrogen as a nitrogen source and silane or derivative thereof as a silicon source.
Claim 4
Dependent Claim
23 words
The process of claim 1 in which the silicon nitride film has a SiO 2 equivalent film thickness of 50 to 100 Å.
Claim 5
Dependent Claim
17 words
The process of claim 1 in which the silicon oxide layer is formed by a thermal oxidation.
Claim 6
Dependent Claim
19 words
The process of claim 1 in which the silicon oxide layer has a thickness of 10 to 20 Å.
Claim 7
Dependent Claim
17 words
The process of claim 1 in which the silicon oxide layer is removed by wet-etching or dry-etching.
Claim 8
Dependent Claim
18 words
The process of claim 6 in which the wet-etching is conducted by using an etchant containing hydrogen fluoride.
Claim 9
Dependent Claim
23 words
The process of claim 1 in which the substrate comprises a silicon wafer or a silicon wafer laminated with a polycrystalline silicon layer.
Claim 10
Dependent Claim
15 words
The process of claim 8 in which the substrate further includes an oxide layer thereover.
Claim 11
Dependent Claim
22 words
The process of claim 9 in which the oxide layer comprises a layer of SiO 2 or Ta 2 O 5 .
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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) | 1994-05-06 | 1994-11-05 | 1995-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-06 | 1998-11-05 | 1999-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-06 | 2002-11-05 | 2003-05-07 | $7700.00 | Window Closed / Lapsed |