Patent US5707898A successfully refreshed from Google Patents.
US5707898A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming a programmable non-volatile memory cell by providing a shielding layer over the gate sidewalls
Assignee: Round Rock Research LLC
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Filing: 1996-04-01
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Granted: 1998-01-13
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Expires: 2016-04-01
Abstract
Abstract A method of reducing undesired electron depletion through sidewalls of a floating gate of a floating gate transistor comprising providing a non-oxide or oxynitride layer over said sidewalls. Integrated circuitry including a non-volatile field effect transistor includes, a) a floating gate transistor having a gate construction and a pair of opposing source/drain regions, the gate construction having at least one sidewall; b) a shielding layer over the gate sidewall; and c) a dielectric layer on the shielding layer, the dielectric layer being of a different material than the shielding layer. The shielding layer might be provided over an oxide layer previously provided on sidewalls of the gate construction. The shielding layer might be provided over sidewall spacers previously provided relative to sidewalls of the gate construction. Example and preferred shielding layer materials include Si 3 N 4 , oxynitride compounds, and aluminum.
Inventors
- 👤 J. Dennis Keller
- 👤 Roger R. Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:31
CPC Classifications
H; H10; H10W; H10W42/00; H10W42/20; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0411; H10D30/60; H10D30/68; H10D30/6891
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
79 words
A method of forming a floating gate transistor, comprising: forming a floating gate construction having opposing lateral sidewalls; providing opposing source and drain regions operably adjacent the floating gate construction; forming an oxide layer over the gate sidewalls; forming a shielding layer over the oxide layer; forming sidewall spacers over the shielding layer and outwardly of the sidewalls; and forming a dielectric layer over the sidewall spacers, the dielectric layer being of a material different than the shielding layer.
Claim 2
Independent Claim
79 words
A method of forming a floating gate transistor, comprising: forming a floating gate construction having opposing lateral sidewalls; providing opposing source and drain regions operably adjacent the floating gate construction; forming an oxide layer over the gate sidewalls; forming a shielding layer over the oxide layer; forming sidewall spacers over the shielding layer and outwardly of the sidewalls; and forming a dielectric layer over the sidewall spacers, the dielectric layer being of a material different than the shielding layer.
Claim 3
Dependent Claim
15 words
A method as claimed in claim 1, wherein the shielding layer comprises a non-oxide material.
Claim 4
Dependent Claim
28 words
A method as claimed in claim 1, wherein the shielding layer comprises Si 3 N 4 having a thickness of from about 50 Angstroms to about 200 Angstroms.
Claim 5
Dependent Claim
13 words
A method as claimed in claim 1, wherein the shielding layer comprises aluminum.
Claim 6
Dependent Claim
24 words
A method as claimed in claim 1, wherein the dielectric layer is selected from the group which comprises BPSG and undoped SiO 2 .
Claim 7
Independent Claim
80 words
A method of forming a floating gate transistor, comprising: forming a floating gate construction having opposing lateral sidewalls; providing opposing source and drain regions operably adjacent the floating gate construction; forming an oxide layer over the gate sidewalls; forming sidewall spacers over the oxide layer and outwardly of the gate sidewalls; forming a shielding layer over the sidewall spacers; and forming a dielectric layer over the shielding layer, the dielectric layer being of a different material than the shielding layer.
Claim 8
Independent Claim
80 words
A method of forming a floating gate transistor, comprising: forming a floating gate construction having opposing lateral sidewalls; providing opposing source and drain regions operably adjacent the floating gate construction; forming an oxide layer over the gate sidewalls; forming sidewall spacers over the oxide layer and outwardly of the gate sidewalls; forming a shielding layer over the sidewall spacers; and forming a dielectric layer over the shielding layer, the dielectric layer being of a different material than the shielding layer.
Claim 9
Dependent Claim
15 words
A method as claimed in claim 6, wherein the shielding layer comprises a non-oxide material.
Claim 10
Dependent Claim
28 words
A method as claimed in claim 6, wherein the shielding layer comprises Si 3 N 4 having a thickness of from about 50 Angstroms to about 200 Angstroms.
Claim 11
Dependent Claim
13 words
A method as claimed in claim 6, wherein the shielding layer comprises aluminum.
Claim 12
Dependent Claim
24 words
A method as claimed in claim 6, wherein the dielectric layer is selected from the group which comprises BPSG and undoped SiO 2 .
Claim 13
Independent Claim
111 words
A method of forming a floating gate transistor, comprising: forming a floating gate construction having opposing lateral sidewalls; providing opposing source and drain regions operably adjacent the floating gate construction; forming an oxide layer over the gate sidewalls; forming a shielding layer over the oxide layer, the shielding layer comprising Si 3 N 4 having a thickness of about 50 Angstroms to about 200 Angstroms; forming sidewall spacers over the shielding layer and outwardly of the sidewalls; and forming a dielectric layer over the sidewall spacers, the dielectric layer being of a material different than the shielding layer, the dielectric layer selected from the group comprising BPSG and SiO 2 .
Claim 14
Independent Claim
111 words
A method of forming a floating gate transistor, comprising: forming a floating gate construction having opposing lateral sidewalls; providing opposing source and drain regions operably adjacent the floating gate construction; forming an oxide layer over the gate sidewalls; forming a shielding layer over the oxide layer, the shielding layer comprising Si 3 N 4 having a thickness of about 50 Angstroms to about 200 Angstroms; forming sidewall spacers over the shielding layer and outwardly of the sidewalls; and forming a dielectric layer over the sidewall spacers, the dielectric layer being of a material different than the shielding layer, the dielectric layer selected from the group comprising BPSG and SiO 2 .
Claim 15
Independent Claim
112 words
A method of forming a floating gate transistor, comprising: forming a floating gate construction having opposing lateral sidewalls; providing opposing source and drain regions operably adjacent the floating gate construction; forming an oxide layer over the gate sidewalls; forming sidewall spacers over the oxide layer and outwardly of the gate sidewalls; forming a shielding layer over the sidewall spacers, the shielding layer comprising Si 3 N 4 having a thickness of about 50 Angstroms to about 200 Angstroms; and forming a dielectric layer over the shielding layer, the dielectric layer being of a different material than the shielding layer, the dielectric layer selected from the group comprising BPSG and SiO 2 .
Claim 16
Independent Claim
112 words
A method of forming a floating gate transistor, comprising: forming a floating gate construction having opposing lateral sidewalls; providing opposing source and drain regions operably adjacent the floating gate construction; forming an oxide layer over the gate sidewalls; forming sidewall spacers over the oxide layer and outwardly of the gate sidewalls; forming a shielding layer over the sidewall spacers, the shielding layer comprising Si 3 N 4 having a thickness of about 50 Angstroms to about 200 Angstroms; and forming a dielectric layer over the shielding layer, the dielectric layer being of a different material than the shielding layer, the dielectric layer selected from the group comprising BPSG and SiO 2 .
Claim 17
Independent Claim
108 words
A method of forming a floating gate transistor, comprising: forming a floating gate construction having opposing lateral sidewalls; providing opposing source and drain regions operably adjacent the floating gate construction; forming an oxide layer over the gate sidewalls; forming a shielding layer over the oxide layer, the shielding layer comprising aluminum having a thickness of about 50 Angstroms to about 200 Angstroms; forming sidewall spacers over the shielding layer and outwardly of the sidewalls; and forming a dielectric layer over the sidewall spacers, the dielectric layer being of a material different than the shielding layer, the dielectric layer selected from the group comprising BPSG and SiO 2 .
Claim 18
Independent Claim
108 words
A method of forming a floating gate transistor, comprising: forming a floating gate construction having opposing lateral sidewalls; providing opposing source and drain regions operably adjacent the floating gate construction; forming an oxide layer over the gate sidewalls; forming a shielding layer over the oxide layer, the shielding layer comprising aluminum having a thickness of about 50 Angstroms to about 200 Angstroms; forming sidewall spacers over the shielding layer and outwardly of the sidewalls; and forming a dielectric layer over the sidewall spacers, the dielectric layer being of a material different than the shielding layer, the dielectric layer selected from the group comprising BPSG and SiO 2 .
Claim 19
Independent Claim
109 words
A method of forming a floating gate transistor, comprising: forming a floating gate construction having opposing lateral sidewalls; providing opposing source and drain regions operably adjacent the floating gate construction; forming an oxide layer over the gate sidewalls; forming sidewall spacers over the oxide layer and outwardly of the gate sidewalls; forming a shielding layer over the sidewall spacers, the shielding layer comprising aluminum having a thickness of about 50 Angstroms to about 200 Angstroms; and forming a dielectric layer over the shielding layer, the dielectric layer being of a different material than the shielding layer, the dielectric layer selected from the group comprising BPSG and SiO 2 .
Claim 20
Independent Claim
109 words
A method of forming a floating gate transistor, comprising: forming a floating gate construction having opposing lateral sidewalls; providing opposing source and drain regions operably adjacent the floating gate construction; forming an oxide layer over the gate sidewalls; forming sidewall spacers over the oxide layer and outwardly of the gate sidewalls; forming a shielding layer over the sidewall spacers, the shielding layer comprising aluminum having a thickness of about 50 Angstroms to about 200 Angstroms; and forming a dielectric layer over the shielding layer, the dielectric layer being of a different material than the shielding layer, the dielectric layer selected from the group comprising BPSG and SiO 2 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-01-12 | 2001-07-14 | 2002-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-01-12 | 2005-07-14 | 2006-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-01-12 | 2009-07-14 | 2010-01-13 | $7700.00 | Window Closed / Lapsed |