US6319802B1
Expired / Lapsed
US
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T-gate formation using modified damascene processing with two masks
Assignee: GlobalFoundries Inc
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Filing: 2000-07-20
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Granted: 2001-11-20
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Expires: 2020-07-20
Abstract
Abstract A method for fabricating a T-gate structure is provided. A structure is provided that has a silicon layer having a gate oxide layer, a protection layer over the gate oxide layer and a sacrificial layer over the protection layer. An opening is then formed in the sacrificial layer. A contact material is deposited over the sacrificial layer filling the opening with the contact material and forming a contact layer. Portions of the contact material outside a gate region are then removed. Finally, the sacrificial layer and portions of the protection layer and the gate oxide layer not forming a part of the T-gate structure are removed.
Inventors
- 👤 Ramkumar Subramanian
- 👤 Christopher F. Lyons
- 👤 Bhanwar Singh
- 👤 Marina Plat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:34
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01324
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
97 words
A method for fabricating a T-gate structure comprising the steps of: providing a silicon layer having a gate oxide layer, a protection layer over the gate oxide layer and a sacrificial layer over the protection layer; forming an opening in the sacrificial layer; depositing a contact material over the sacrificial layer filling the opening with the contact material and forming a contact layer; removing portions of the contact material outside a gate region; and removing the sacrificial layer and portions of the protection layer and the gate oxide layer not forming a part of the T-gate structure.
Claim 2
Independent Claim
97 words
A method for fabricating a T-gate structure comprising the steps of: providing a silicon layer having a gate oxide layer, a protection layer over the gate oxide layer and a sacrificial layer over the protection layer; forming an opening in the sacrificial layer; depositing a contact material over the sacrificial layer filling the opening with the contact material and forming a contact layer; removing portions of the contact material outside a gate region; and removing the sacrificial layer and portions of the protection layer and the gate oxide layer not forming a part of the T-gate structure.
Claim 3
Dependent Claim
43 words
The method of claim 1 , the sacrificial layer including at least one of silicon oxide, silicon dioxide, silicon nitride (Si 3 N 4 ), (SiN), silicon oxynitride, (SiO x N y ), fluorinated silicon oxide (SiO x N y ), and polyimide(s).
Claim 4
Dependent Claim
27 words
The method of claim 1 , the step of depositing a contact material comprising the step of depositing with one of polysilicon, germanium, amorphous polysilicon and metal.
Claim 5
Dependent Claim
49 words
The method of claim 1 , the step of forming an opening in the sacrificial layer comprising etching the sacrificial layer to form a first opening in a photoresist layer to expose the sacrificial layer and a second step of etching the exposed sacrificial layer to form the opening.
Claim 6
Dependent Claim
21 words
The method of claim 4 , the first etching step being employed utilizing a dark field mask with a positive resist.
Claim 7
Dependent Claim
29 words
The method of claim 5 , the step of removing portions of the contact material outside a gate region comprising performing an etch step employing a clear field mask.
Claim 8
Dependent Claim
21 words
The method of claim 4 , the first etching step being employed utilizing a clear field mask with a negative resist.
Claim 9
Dependent Claim
29 words
The method of claim 7 , the step of removing portions of the contact material outside a gate region comprising performing an etch step employing a dark field mask.
Claim 10
Dependent Claim
22 words
The method of claim 4 , the first etch step being highly selective to the photoresist layer over the underlying sacrificial layer.
Claim 11
Dependent Claim
26 words
The method of claim 4 , the second etch step being highly selective to the sacrificial layer over the photoresist layer and the underlying protection layer.
Claim 12
Dependent Claim
36 words
The method of claim 1 , the step of removing portions of the sacrificial layer, the protection layer and the gate oxide layer not forming a part of the T-gate structure comprising performing a wet etch.
Claim 13
Dependent Claim
37 words
The method of claim 1 , the step of removing portions of the sacrificial layer, the protection layer and the gate oxide layer not forming a part of the T-gate structure comprising performing a vertical plasma etch.
Claim 14
Dependent Claim
17 words
The method of claim 1 , the protection layer being formed from one of polysilicon and germanium.
Claim 15
Dependent Claim
29 words
The method of claim 1 , further including the step of forming the protection layer to have a thickness within the range of about 50 Å to 150 Å.
Claim 16
Dependent Claim
29 words
The method of claim 1 , further including the step of forming the sacrificial layer to have a thickness within the range of about 400 Å to 600 Å.
Claim 17
Independent Claim
122 words
A method for fabricating a T-gate structure comprising the steps of: providing a silicon layer having a gate oxide layer, a protection layer over the gate oxide layer and a sacrificial layer over the protection layer, the protection layer being one of a polysilicon and a germanium material; forming an opening in the sacrificial layer; depositing a contact material over the sacrificial layer filling the opening with the contact material and forming a contact layer, the contact material being one of a polysilicon material and a germanium material; removing portions of the contact material outside a gate region; and removing the sacrificial layer and portions of the protection layer and the gate oxide layer not forming a part of the T-gate structure.
Claim 18
Independent Claim
122 words
A method for fabricating a T-gate structure comprising the steps of: providing a silicon layer having a gate oxide layer, a protection layer over the gate oxide layer and a sacrificial layer over the protection layer, the protection layer being one of a polysilicon and a germanium material; forming an opening in the sacrificial layer; depositing a contact material over the sacrificial layer filling the opening with the contact material and forming a contact layer, the contact material being one of a polysilicon material and a germanium material; removing portions of the contact material outside a gate region; and removing the sacrificial layer and portions of the protection layer and the gate oxide layer not forming a part of the T-gate structure.
Claim 19
Dependent Claim
43 words
The method of claim 16 , the sacrificial layer including at least one of silicon oxide, silicon dioxide, silicon nitride (Si 3 N 4 ), (SiN), silicon oxynitride, (SiO x N y ), fluorinated silicon oxide (SiO x F y ), and polyimide(s).
Claim 20
Dependent Claim
29 words
The method of claim 16 , further including the step of forming the protection layer to have a thickness within the range of about 50 Å to 150 Å.
Claim 21
Dependent Claim
29 words
The method of claim 16 , further including the step of forming the sacrificial layer to have a thickness within the range of about 400 Å to 600 Å.
Claim 22
Independent Claim
147 words
A method for fabricating a T-gate structure comprising the steps of: providing a silicon layer having a gate oxide layer, a protection layer having a thickness within the range of about 50 Å to 150 Å over the gate oxide layer and a sacrificial layer having a thickness within the range of about 400 Å to 600 Å over the protection layer, the protection layer being formed from one of a polysilicon and germanium material; etching an opening in the sacrificial layer; depositing a polysilicon material over the sacrificial layer filling the opening with the polysilicon material and forming a polysilicon layer; removing portions of the polysilicon material outside a gate region; removing the sacrificial layer; and etching portions of the protection layer and the gate oxide layer not forming a part of the T-gate structure using one of a wet etch and a vertical plasma etch.
Claim 23
Independent Claim
147 words
A method for fabricating a T-gate structure comprising the steps of: providing a silicon layer having a gate oxide layer, a protection layer having a thickness within the range of about 50 Å to 150 Å over the gate oxide layer and a sacrificial layer having a thickness within the range of about 400 Å to 600 Å over the protection layer, the protection layer being formed from one of a polysilicon and germanium material; etching an opening in the sacrificial layer; depositing a polysilicon material over the sacrificial layer filling the opening with the polysilicon material and forming a polysilicon layer; removing portions of the polysilicon material outside a gate region; removing the sacrificial layer; and etching portions of the protection layer and the gate oxide layer not forming a part of the T-gate structure using one of a wet etch and a vertical plasma etch.
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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) | 2004-11-19 | 2005-05-21 | 2005-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-11-19 | 2009-05-21 | 2009-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-11-19 | 2013-05-21 | 2013-11-20 | $7700.00 | Window Closed / Lapsed |