US6255202B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Damascene T-gate using a spacer flow
Assignee: GlobalFoundries Inc
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Filing: 2000-07-20
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Granted: 2001-07-03
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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 polysilicon layer over the gate oxide layer and an insulating layer over the gate oxide layer. An opening is formed extending partially into the insulating layer. The opening in the insulating layer extends from a top surface of the insulating layer to a first depth. Spacers are then formed on the sides of the opening. The opening is then extended in the insulating layer from the first depth to a second depth. The opening is wider from the top surface of the insulating layer to the first depth than the opening is from the first depth to the second depth. The spacers are then removed from the opening. The opening is then filled with a conductive material to form a T-gate structure.
Inventors
- 👤 Christopher F. Lyons
- 👤 Ramkumar Subramanian
- 👤 Bhanwar Singh
- 👤 Marina Plat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:43
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0225; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01324; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/517; H10D64/519; H10D64/01326; H10D64/60; H10D64/66; H10D64/661; H10D64/662; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081; H10W20/084
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
144 words
A method for fabricating a T-gate structure comprising the steps of: providing a silicon layer having a gate oxide layer, a polysilicon layer over the gate oxide layer and an insulating layer over the gate oxide layer; forming a photoresist layer over the insulating layer; forming an opening in the insulating layer extending from a top surface of the insulating layer to a first depth; forming spacers in the opening to reduce the size of the opening in the insulating layer; extending the opening in the insulating layer from the first depth to a second depth wherein the opening is wider from the top surface of the insulating layer to the first depth than the opening is from the first depth to the second depth; removing the spacers from the opening; and filling the opening with a conductive material to form the T-gate structure.
Claim 2
Independent Claim
144 words
A method for fabricating a T-gate structure comprising the steps of: providing a silicon layer having a gate oxide layer, a polysilicon layer over the gate oxide layer and an insulating layer over the gate oxide layer; forming a photoresist layer over the insulating layer; forming an opening in the insulating layer extending from a top surface of the insulating layer to a first depth; forming spacers in the opening to reduce the size of the opening in the insulating layer; extending the opening in the insulating layer from the first depth to a second depth wherein the opening is wider from the top surface of the insulating layer to the first depth than the opening is from the first depth to the second depth; removing the spacers from the opening; and filling the opening with a conductive material to form the T-gate structure.
Claim 3
Dependent Claim
43 words
The method of claim 1 , the insulating layer including at least one of silicon oxide, silicon dioxide, silicon nitride (Si 3 N 4 ), (SiN), silicon oxynitride, (SiO x N y ), fluonated silicon oxide (SiO x F y ), and polyimide(s).
Claim 4
Dependent Claim
32 words
The method of claim 1 , the step of filling the opening with a conductive material comprising the step of filling the opening with one of polysilicon, germanium, amorphous polysilicon and metal.
Claim 5
Dependent Claim
52 words
The method of claim 1 , the step of forming an opening extending partially through the insulating layer comprising a first step of etching a first opening in a photoresist layer to expose the insulating layer and a second step of partially etching the exposed insulating layer to extend the first opening.
Claim 6
Dependent Claim
21 words
The method of claim 4 , the first etching step being highly selective to the photoresist layer over the insulating layer.
Claim 7
Dependent Claim
21 words
The method of claim 4 , the second etching step being highly selective to the insulating layer over the photoresist layer.
Claim 8
Dependent Claim
44 words
The method of claim 1 , the step of extending the opening in the insulating layer from the first depth to a second depth comprising performing an etch step being highly selective to the insulating layer over the spacers and the underlying polysilicon layer.
Claim 9
Dependent Claim
15 words
The method of claim 1 , the second depth extending to the underlying polysilicon layer.
Claim 10
Dependent Claim
31 words
The method of claim 1 , the step of forming spacers in the opening comprising depositing a spacer material in the opening and etching through a central region of the opening.
Claim 11
Dependent Claim
19 words
The method of claim 1 , the spacers being formed from one of tetraethoxysilane (TEOS) oxide and silicon dioxide.
Claim 12
Dependent Claim
27 words
The method of claim 1 , the spacers being formed from a nitride and the step of removing the spacers comprising dipping the structure in phosphoric acid.
Claim 13
Dependent Claim
26 words
The method of claim 1 , further comprising the step of removing the insulating layer after the step of filling the opening with a conductive material.
Claim 14
Dependent Claim
36 words
The method of claim 12 , further comprising the step of removing the gate oxide material and the polysilicon layer not underlying the conductive material after the step of filling the opening with a conductive material.
Claim 15
Dependent Claim
29 words
The method of claim 1 , further including the step of forming the photoresist layer to have a thickness within the range of about 1000 Å to 15000 Å.
Claim 16
Dependent Claim
29 words
The method of claim 1 , further including the step of forming the photoresist layer to have a thickness within the range of about 1000 Å to 12000 Å.
Claim 17
Dependent Claim
29 words
The method of claim 1 , further including the step of forming the photoresist layer to have a thickness within the range of about 200 Å to 8000 Å.
Claim 18
Independent Claim
188 words
A method for fabricating a T-gate structure comprising the steps of: providing a silicon layer having a gate oxide layer, a polysilicon layer over the gate oxide layer and an insulating layer over the gate oxide layer; forming a photoresist layer over the insulating layer; etching an opening in the photoresist layer exposing a portion of the insulating layer; etching partially the exposed portion of the insulating layer to extend the opening partially into the insulating layer, the opening in the insulating layer extending from a top surface of the insulating layer to a first depth; forming spacers in the opening to reduce the size of the opening in the insulating layer; etching the opening in the insulating layer from the first depth to a second depth wherein the opening is wider from the top surface of the insulating layer to the first depth than the opening is from the first depth to the second depth; removing the spacers; filling the opening with a conductive material to form the T-gate structure; and removing the insulating layer and the gate oxide and polysilicon layer not underlying the conductive material.
Claim 19
Independent Claim
188 words
A method for fabricating a T-gate structure comprising the steps of: providing a silicon layer having a gate oxide layer, a polysilicon layer over the gate oxide layer and an insulating layer over the gate oxide layer; forming a photoresist layer over the insulating layer; etching an opening in the photoresist layer exposing a portion of the insulating layer; etching partially the exposed portion of the insulating layer to extend the opening partially into the insulating layer, the opening in the insulating layer extending from a top surface of the insulating layer to a first depth; forming spacers in the opening to reduce the size of the opening in the insulating layer; etching the opening in the insulating layer from the first depth to a second depth wherein the opening is wider from the top surface of the insulating layer to the first depth than the opening is from the first depth to the second depth; removing the spacers; filling the opening with a conductive material to form the T-gate structure; and removing the insulating layer and the gate oxide and polysilicon layer not underlying the conductive material.
Claim 20
Dependent Claim
15 words
The method of claim 17 , the second depth extending to the underlying polysilicon layer.
Claim 21
Dependent Claim
31 words
The method of claim 17 , the step of forming spacers in the opening comprising depositing a spacer material in the opening and etching through a central region of the opening.
Claim 22
Independent Claim
230 words
A method for fabricating a T-gate structure comprising the steps of: providing a silicon layer having a gate oxide layer, a polysilicon layer over the gate oxide layer and an insulating layer over the gate oxide layer; forming a photoresist layer over the insulating layer, the photoresist layer having a thickness within the range of about 1000 Å to 15000 Å; etching an opening in the photoresist layer exposing a portion of the insulating layer, the etching being highly selective to the photoresist layer over the underlying insulating layer; etching the exposed portion of the insulating layer to extend the opening partially into the insulating layer, the opening in the insulating layer extending from a top surface of the insulating layer to a first depth, the etching being highly selective to the insulating layer over the photoresist layer; forming spacers in the opening to reduce the size of the opening in the insulating layer; etching the opening in the insulating layer from the first depth to the polysilicon layer wherein the opening is wider from the top surface of the insulating layer to the first depth than the opening is from the first depth to the polysilicon layer; removing the spacers; filling the opening with a conductive material to from the T-gate structure; and removing the insulating layer and the gate oxide and polysilicon layer not underlying the conductive material.
Claim 23
Independent Claim
230 words
A method for fabricating a T-gate structure comprising the steps of: providing a silicon layer having a gate oxide layer, a polysilicon layer over the gate oxide layer and an insulating layer over the gate oxide layer; forming a photoresist layer over the insulating layer, the photoresist layer having a thickness within the range of about 1000 Å to 15000 Å; etching an opening in the photoresist layer exposing a portion of the insulating layer, the etching being highly selective to the photoresist layer over the underlying insulating layer; etching the exposed portion of the insulating layer to extend the opening partially into the insulating layer, the opening in the insulating layer extending from a top surface of the insulating layer to a first depth, the etching being highly selective to the insulating layer over the photoresist layer; forming spacers in the opening to reduce the size of the opening in the insulating layer; etching the opening in the insulating layer from the first depth to the polysilicon layer wherein the opening is wider from the top surface of the insulating layer to the first depth than the opening is from the first depth to the polysilicon layer; removing the spacers; filling the opening with a conductive material to from the T-gate structure; and removing the insulating layer and the gate oxide and polysilicon layer not underlying the conductive material.
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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) | 2004-07-02 | 2005-01-01 | 2005-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-07-02 | 2009-01-01 | 2009-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-07-02 | 2013-01-01 | 2013-07-03 | $7700.00 | Window Closed / Lapsed |