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US6270929B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Damascene T-gate using a relacs flow

Assignee: GlobalFoundries Inc
•
Filing: 2000-07-20
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Granted: 2001-08-07
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Expires: 2020-07-20
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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. A photoresist layer is formed over the insulating layer. An opening is the formed extending through the photoresist layer and partially into the insulating layer. The opening in the insulating layer extends from a top surface of the insulating layer to a first depth. The photoresist layer is swelled to reduce the size of the opening in the photoresist layer. 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 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 2026-10-30 08:03
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01324; H10P; H10P50/00; H10P50/73; H10P76/00; H10P76/20; H10P76/204; H10P76/40; H10P76/408; H10P76/4088; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/517; H10D64/518; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081

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 polysilicon layer; forming a photoresist layer over the insulating layer; forming an opening extending through the photoresist layer and partially into the insulating layer, the opening in the insulating layer extending from a top surface of the insulating layer to a first depth; swelling the photoresist layer to reduce the size of the opening in the photoresist 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; and filling the opening with a conductive material.
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 polysilicon layer; forming a photoresist layer over the insulating layer; forming an opening extending through the photoresist layer and partially into the insulating layer, the opening in the insulating layer extending from a top surface of the insulating layer to a first depth; swelling the photoresist layer to reduce the size of the opening in the photoresist 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; and filling the opening with a conductive material.
Claim 3
Dependent Claim 27 words
The method of claim 1 , the insulating layer including at least one of silicon oxide, silicon dioxide, silicon nitride, silicon oxynitride, fluonated silicon oxide 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 58 words
The method of claim 1 , the step of forming a first opening extending through the photoresist layer and partially into the insulating layer comprising a first step of etching a first opening in the 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 45 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 photoresist layer 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 swelling the photoresist layer to reduce the size of the opening in the photoresist layer comprising wetting the resist with a solvent.
Claim 11
Dependent Claim 32 words
The method of claim 1 , the step of swelling the photoresist layer to reduce the size of the opening in the photoresist layer comprising treating the resist with an organic material.
Claim 12
Dependent Claim 32 words
The method of claim 1 , the step of swelling the photoresist layer to reduce the size of the opening in the photoresist layer comprising using a hydrophilic resin with swelling properties.
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 178 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 polysilicon 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; swelling the photoresist layer to reduce the size of the opening in the photoresist 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; filling the opening with a conductive material; and removing the insulating layer and the gate oxide and polysilicon layer not underlying the conductive material.
Claim 19
Independent Claim 178 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 polysilicon 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; swelling the photoresist layer to reduce the size of the opening in the photoresist 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; filling the opening with a conductive material; 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 swelling the photoresist layer to reduce to size of the opening in the photoresist layer comprising wetting the resist with a solvent.
Claim 22
Independent Claim 227 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 to 15000; 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; swelling the photoresist layer to reduce the size of the opening in the photoresist layer by wetting the photoresist layer with a solvent; 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; filling the opening with a conductive material; and removing the insulating layer and the gate oxide and polysilicon layer not underlying the conductive material.
Claim 23
Independent Claim 227 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 to 15000; 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; swelling the photoresist layer to reduce the size of the opening in the photoresist layer by wetting the photoresist layer with a solvent; 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; filling the opening with a conductive material; and removing the insulating layer and the gate oxide and polysilicon layer not underlying the conductive material.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2004-08-06 2005-02-05 2005-08-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2008-08-06 2009-02-05 2009-08-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2012-08-06 2013-02-05 2013-08-07 $7700.00 Window Closed / Lapsed

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