US6352885B1
Expired / Lapsed
US
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Transistor having a peripherally increased gate insulation thickness and a method of fabricating the same
Assignee: GlobalFoundries Inc
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Filing: 2000-05-25
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Granted: 2002-03-05
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Expires: 2020-05-25
Abstract
Abstract A transistor having a gate insulation layer whose peripheral portion has an increased thickness and a method of fabricating these transistor devices is disclosed. The peripheral portions with increased thickness of the gate insulation layer significantly reduce the injection of charge carriers into the gate insulation layer. Accordingly, the transistors described in the present application exhibit an improved long-time reliability. In addition, the lateral penetration of ions beneath the gate insulation layer for forming the lightly-doped drain and/or the lightly doped source is increased since the implantation may be performed at a tilt angle with respect to the perpendicular direction which is the conventionally used direction of the implantation step.
Inventors
- 👤 Karsten Wieczorek
- 👤 Frederick N. Hause
- 👤 Manfred Horstmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:35
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/514; H10D64/516; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H10P; H10P30/00; H10P30/20; H10P30/222; Y; Y10; Y10S; Y10S438/00; Y10S438/981
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
150 words
A method of manufacturing a field effect transistor, comprising the steps: providing a semiconductor substrate having a surface comprising an active region; forming a gate insulation layer above the active region; forming a gate electrode material above the gate insulation layer; patterning the gate electrode material to form a gate electrode therefrom, said gate electrode having a top surface; removing an edge portion of the originally-formed gate insulation layer covered by the gate electrode to form a gap adjacent each side of said gate insulation layer between said gate electrode and said active region; performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate, the top surface of said gate electrode and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide; and performing at least one ion implant process through said screen oxide layer.
Claim 2
Independent Claim
150 words
A method of manufacturing a field effect transistor, comprising the steps: providing a semiconductor substrate having a surface comprising an active region; forming a gate insulation layer above the active region; forming a gate electrode material above the gate insulation layer; patterning the gate electrode material to form a gate electrode therefrom, said gate electrode having a top surface; removing an edge portion of the originally-formed gate insulation layer covered by the gate electrode to form a gap adjacent each side of said gate insulation layer between said gate electrode and said active region; performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate, the top surface of said gate electrode and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide; and performing at least one ion implant process through said screen oxide layer.
Claim 3
Dependent Claim
26 words
The method of claim 1 , wherein forming a gate insulation layer above the active region comprises depositing a gate insulation layer above the active region.
Claim 4
Dependent Claim
27 words
The method of claim 1 , wherein forming a gate insulation layer above the active region comprises thermally growing a gate insulation layer above the active region.
Claim 5
Dependent Claim
41 words
The method of claim 1 , wherein forming a gate insulation layer above the active region comprises forming a gate insulation layer comprised of at least one of an oxide, an oxynitride, silicon dioxide, and silicon nitride above the active region.
Claim 6
Dependent Claim
28 words
The method of claim 1 , wherein forming a gate electrode material above the gate insulation layer comprises depositing a gate electrode material above the gate insulation layer.
Claim 7
Dependent Claim
32 words
The method of claim 1 , wherein forming a gate electrode material above the gate insulation layer comprises forming a gate electrode material comprised of polycrystalline silicon above the gate insulation layer.
Claim 8
Dependent Claim
30 words
The method of claim 1 , wherein patterning the gate electrode material to form a gate electrode therefrom comprises etching the gate electrode material to form a gate electrode therefrom.
Claim 9
Dependent Claim
99 words
The method of claim 1 , wherein performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate, the top surface of said gate electrode and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide, comprises performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate, the top surface of said gate electrode and a portion of a bottom surface of the gate electrode in an ambient comprising nitrogen, thereby filling the gaps with the screen oxide.
Claim 10
Dependent Claim
112 words
The method of claim 1 , wherein performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate, the top surface of said gate electrode and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide, comprises performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate, the top surface of said gate electrode and a portion of a bottom surface of the gate electrode in an ambient comprising at least one of N 2 O 2 , N 2 O, and NO, thereby filling the gaps with the screen oxide.
Claim 11
Dependent Claim
112 words
The method of claim 1 , wherein performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate, the top surface of said gate electrode and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide, comprises performing an oxidation process to grow a screen oxide layer having a thickness equal to or larger than a thickness of the gate insulation layer as initially formed by oxidizing the surface of the substrate, the top surface of said gate electrode and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide.
Claim 12
Dependent Claim
66 words
The method of claim 1 , wherein removing an edge portion of the originally-formed gate insulation layer covered by the gate electrode to form a gap between said gate electrode and said active region adjacent each side of said gate insulation layer comprises under-etching the gate electrode to form a gap adjacent each side of said gate insulation layer between said electrode and said active region.
Claim 13
Dependent Claim
111 words
The method of claim 1 , wherein performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate, the top surface of said gate electrode and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide, comprises performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate, the top surface of said gate electrode and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide, each gap having a lateral dimension that is approximately 5-20% of a length of said gate electrode.
Claim 14
Dependent Claim
74 words
The method of claim 1 , further comprising: forming lightly doped drain regions and lightly doped source by implanting ions having a primary moving direction substantially perpendicular to the surface of the substrate, and implanting ions moving in a direction that forms a tilt-angle with respect to the surface of the substrate so as to achieve a deeper lateral penetration of the ions under the gate insulation layer, thereby forming a low resistance region.
Claim 15
Independent Claim
156 words
A method of manufacturing a field effect transistor, comprising the steps: providing a semiconductor substrate comprised of silicon having a surface comprising an active region; forming a gate insulation layer above the active region; depositing a gate electrode material comprised of polysilicon above the gate insulation layer; etching the gate electrode material to form a gate electrode therefrom, said gate electrode having a top surface; removing an edge portion of the originally-formed gate insulation layer covered by the gate electrode to form a gap adjacent each side of said gate insulation layer between said gate electrode and said active region; performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate, the top surface of said gate electrode and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide; and performing at least one ion implant process through said screen oxide layer.
Claim 16
Independent Claim
156 words
A method of manufacturing a field effect transistor, comprising the steps: providing a semiconductor substrate comprised of silicon having a surface comprising an active region; forming a gate insulation layer above the active region; depositing a gate electrode material comprised of polysilicon above the gate insulation layer; etching the gate electrode material to form a gate electrode therefrom, said gate electrode having a top surface; removing an edge portion of the originally-formed gate insulation layer covered by the gate electrode to form a gap adjacent each side of said gate insulation layer between said gate electrode and said active region; performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate, the top surface of said gate electrode and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide; and performing at least one ion implant process through said screen oxide layer.
Claim 17
Dependent Claim
26 words
The method of claim 14 , wherein forming a gate insulation layer above the active region comprises depositing a gate insulation layer above the active region.
Claim 18
Dependent Claim
27 words
The method of claim 14 , wherein forming a gate insulation layer above the active region comprises thermally growing a gate insulation layer above the active region.
Claim 19
Dependent Claim
41 words
The method of claim 14 , wherein forming a gate insulation layer above the active region comprises forming a gate insulation layer comprised of at least one of an oxide, an oxynitride, silicon dioxide, and silicon nitride above the active region.
Claim 20
Dependent Claim
98 words
The method of claim 14 , wherein performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide, comprises performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate and a portion of a bottom surface of the gate electrode in an ambient comprising at least one of N 2 O 2 , N 2 O, and NO, thereby filling the gaps with the screen oxide.
Claim 21
Dependent Claim
98 words
The method of claim 14 , wherein performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide, comprises performing an oxidation process to grow a screen oxide layer having a thickness equal to or larger than a thickness of the gate insulation layer as initially formed by oxidizing the surface of the substrate and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide.
Claim 22
Dependent Claim
63 words
The method of claim 14 , wherein removing an edge portion of the originally-formed gate insulation layer covered by the gate electrode to form a gap between said gate electrode and said active region adjacent said gate insulation layer comprises under-etching the gate electrode to form a gap adjacent each side of said gate insulation layer between said electrode and said active region.
Claim 23
Dependent Claim
101 words
The method of claim 14 , wherein performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide, comprises performing an oxidation process to grow a screen oxide layer by oxidizing the surface of the substrate and a portion of a bottom surface of the gate electrode, thereby filling the gaps with the screen oxide, each of said gaps having a lateral dimension that is approximately 5-20 percent of the gate length of said gate electrode.
Claim 24
Dependent Claim
74 words
The method of claim 14 , further comprising: forming lightly doped drain regions and lightly doped source by implanting ions having a primary moving direction substantially perpendicular to the surface of the substrate, and implanting ions moving in a direction that forms a tilt-angle with respect to the surface of the substrate so as to achieve a deeper lateral penetration of the ions under the gate insulation layer, thereby forming a low resistance region.
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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) | 2005-03-04 | 2005-09-03 | 2006-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-03-04 | 2009-09-03 | 2010-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-03-04 | 2013-09-03 | 2014-03-05 | $7700.00 | Window Closed / Lapsed |