US5445982A
Expired / Lapsed
US
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Method of fabricating nonvolatile semiconductor memory device
Assignee: SK Hynix Inc
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Filing: 1994-03-17
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Granted: 1995-08-29
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Expires: 2014-03-17
Abstract
Abstract A method of fabricating a nonvolatile semiconductor memory device so as to improve interface properties between a tunneling oxide layer and a floating gate of the nonvolatile semiconductor memory device is disclosed, wherein the method comprises the steps of forming a tunneling oxide layer on a substrate, forming a floating gate consisting of a plurality of thin silicon layers which are formed through the repeated cyclical process under the low temperature of around 550 degrees C., forming an interposed insulating layer over a whole surface of the floating gate by a selective etching process of the silicon layers; and forming a control gate over a whole surface of the interposed insulating layer.
Inventors
- 👤 Hyun S. Hwang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:47
CPC Classifications
H; H10; H10B; H10B41/00; H10B41/30; H10B41/35; H10B69/00; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/60; H10D64/66; H10D64/661; H10P; H10P14/00; H10P14/20; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/40; H10P14/416; H10P95/00; H10P95/90
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
90 words
A method of fabricating a nonvolatile semiconductor memory device, comprising the steps of: forming a tunneling oxide layer on a substrate; and forming a floating gate comprising a plurality of silicon layers which are formed through a repeated cyclical process under temperatures of around 550 degrees C.; wherein the plurality of silicon layers are formed by repeating a process which includes the steps of depositing a silicon layer with a thickness of 100 to 500 Angstroms at temperatures of about 550 degrees C. and then purging using N 2 .
Claim 2
Independent Claim
90 words
A method of fabricating a nonvolatile semiconductor memory device, comprising the steps of: forming a tunneling oxide layer on a substrate; and forming a floating gate comprising a plurality of silicon layers which are formed through a repeated cyclical process under temperatures of around 550 degrees C.; wherein the plurality of silicon layers are formed by repeating a process which includes the steps of depositing a silicon layer with a thickness of 100 to 500 Angstroms at temperatures of about 550 degrees C. and then purging using N 2 .
Claim 3
Dependent Claim
18 words
The method of claim 1, wherein the silicon layers have an overall thickness of 1500 to 2000 Angstroms.
Claim 4
Independent Claim
116 words
A method of fabricating a nonvolatile semiconductor memory device, comprising the steps of: forming a tunneling oxide layer on a substrate; forming a floating gate comprising a plurality of silicon layers which are formed through a repeated cyclical process under temperatures of around 550 degrees C.; forming an interposed insulating layer over the entire surface of the floating gate; and forming a control gate over the entire surface of the interposed insulating layer; wherein the plurality of silicon layers are formed by repeating a process which includes the step of depositing a silicon layer with a thickness of 100 to 500 Angstroms at temperatures of about 550 degrees C. and then purging using N 2 .
Claim 5
Independent Claim
116 words
A method of fabricating a nonvolatile semiconductor memory device, comprising the steps of: forming a tunneling oxide layer on a substrate; forming a floating gate comprising a plurality of silicon layers which are formed through a repeated cyclical process under temperatures of around 550 degrees C.; forming an interposed insulating layer over the entire surface of the floating gate; and forming a control gate over the entire surface of the interposed insulating layer; wherein the plurality of silicon layers are formed by repeating a process which includes the step of depositing a silicon layer with a thickness of 100 to 500 Angstroms at temperatures of about 550 degrees C. and then purging using N 2 .
Claim 6
Dependent Claim
19 words
The method of claim 3, wherein the silicon layers have an overall thickness of about 1500 to 2000 Angstroms.
Claim 7
Dependent Claim
14 words
The method of claim 4, wherein the interposed insulating layer is made of oxide-nitride-oxide.
Claim 8
Dependent Claim
14 words
The method of claim 3, wherein the interposed insulating layer is made of oxide-nitride-oxide.
References Cited (Backward Citations)
US5147813A
Cited
US5350698A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-08-28 | 1999-02-27 | 1999-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-08-28 | 2003-02-27 | 2003-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-08-28 | 2007-02-27 | 2007-08-29 | $7700.00 | Window Closed / Lapsed |