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US6580118B2
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Non-volatile semiconductor memory cell having a metal oxide dielectric, and method for fabricating the memory cell
Assignee: Infineon Technologies AG
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Filing: 2001-12-10
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Granted: 2003-06-17
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Expires: 2021-12-10
Abstract
Abstract A non-volatile semiconductor memory cell and an associated method are disclosed, in which a conventional dielectric ONO layer ( 10 ) is replaced by a very thin metal oxide layer ( 6 ) of WO x and/or TiO 2 . The high relative dielectric constant of these materials further improves the integration density and the control voltages required for the semiconductor memory cell.
Inventors
- 👤 Christoph Ludwig
- 👤 Martin Schrems
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:25
CPC Classifications
H; H10; H10B; H10B41/00; H10B41/30; H10D; H10D64/00; H10D64/01; H10D64/031; H10D64/035
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
74 words
A non-volatile semiconductor memory cell, comprising: a semiconductor substrate; an insulating tunnel oxide layer; a conductive floating-gate layer; an insulating dielectric layer including at least one metal oxide layer and at least one Si 3 N 4 layer enclosing said metal oxide layer; and a conductive control-gate layer; said metal oxide layer being made of a material selected from the group consisting of WO x , where x=2 to 3, and TiO 2 .
Claim 2
Dependent Claim
74 words
A non-volatile semiconductor memory cell, comprising: a semiconductor substrate; an insulating tunnel oxide layer; a conductive floating-gate layer; an insulating dielectric layer including at least one metal oxide layer and at least one Si 3 N 4 layer enclosing said metal oxide layer; and a conductive control-gate layer; said metal oxide layer being made of a material selected from the group consisting of WO x , where x=2 to 3, and TiO 2 .
Claim 3
Dependent Claim
18 words
The non-volatile semiconductor memory cell according to claim 1 , wherein said floating-gate layer includes a poly-Si layer.
Claim 4
Dependent Claim
30 words
The non-volatile semiconductor memory cell according to claim 2 , wherein said floating-gate layer includes a layer selected from the group consisting of a TiN layer and a WN layer.
Claim 5
Dependent Claim
30 words
The non-volatile semiconductor memory cell according to claim 1 , wherein said floating-gate layer includes a layer selected from the group consisting of a TiN layer and a WN layer.
Claim 6
Dependent Claim
23 words
The non-volatile semiconductor memory cell according to claim 1 , wherein said dielectric layer has a thickness that is greater than 15 nm.
Claim 7
Dependent Claim
26 words
The non-volatile semiconductor memory cell according to claim 1 , wherein said floating-gate layer has a thickness in a range from 5 nm to 50 nm.
Claim 8
Independent Claim
96 words
A method for fabricating a non-volatile semiconductor memory cell, which comprises: a) forming active regions in a semiconductor substrate; b) forming a tunnel oxide layer; c) depositing a floating-gate layer; d) depositing a metal-containing layer that includes a material selected from the group consisting of a metal and a metal compound; e) etching the metal-containing layer and the floating-gate layer; f) oxidizing the metal-containing layer and exposed side regions of the floating-gate layer to form a dielectric layer; g) depositing a control-gate layer; and h) etching the control-gate layer, the dielectric layer, and the floating-gate layer.
Claim 9
Independent Claim
96 words
A method for fabricating a non-volatile semiconductor memory cell, which comprises: a) forming active regions in a semiconductor substrate; b) forming a tunnel oxide layer; c) depositing a floating-gate layer; d) depositing a metal-containing layer that includes a material selected from the group consisting of a metal and a metal compound; e) etching the metal-containing layer and the floating-gate layer; f) oxidizing the metal-containing layer and exposed side regions of the floating-gate layer to form a dielectric layer; g) depositing a control-gate layer; and h) etching the control-gate layer, the dielectric layer, and the floating-gate layer.
Claim 10
Dependent Claim
24 words
The method according to claim 7 , which comprises: in step c) depositing a TiN layer; and in step d) depositing a Ti layer.
Claim 11
Dependent Claim
29 words
The method according to claim 7 , which comprises: in step c) depositing a poly-Si layer; and in step d) depositing a WO x layer, where x=2 to 3.
Claim 12
Dependent Claim
53 words
The method according to claim 7 , which comprises: in steps c) and d) depositing a common tungsten-containing layer; and in step f) performing the oxidizing out until an oxidized partial layer of the tungsten-containing layer forms the dielectric layer and an unoxidized partial layer of the tungsten-containing layer forms the floating-gate layer.
Claim 13
Dependent Claim
22 words
The method according to claim 7 , which comprises: i) forming an insulating intermediate layer on the surface of the control-gate layer.
Claim 14
Dependent Claim
24 words
The method according to claim 11 , which comprises: in step c) depositing a TiN layer; and in step d) depositing a Ti layer.
Claim 15
Dependent Claim
29 words
The method according to claim 11 , which comprises: in step c) depositing a poly-Si layer; and in step d) depositing a WO x layer, where x=2 to 3.
Claim 16
Dependent Claim
53 words
The method according to claim 11 , which comprises: in steps c) and d) depositing a common tungsten-containing layer; and in step f) performing the oxidizing out until an oxidized partial layer of the tungsten-containing layer forms the dielectric layer and an unoxidized partial layer of the tungsten-containing layer forms the floating-gate layer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2006-06-16 | 2006-12-16 | 2007-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-06-16 | 2010-12-16 | 2011-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-06-16 | 2014-12-16 | 2015-06-17 | $7700.00 | Window Closed / Lapsed |