US6087208A
Expired / Lapsed
US
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Method for increasing gate capacitance by using both high and low dielectric gate material
Assignee: Advanced Micro Devices Inc
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Filing: 1998-03-31
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Granted: 2000-07-11
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Expires: 2018-03-31
Abstract
Abstract A method for fabricating a MOSFET device is provided. The method includes a step of fining a gate oxide including first and second gate oxide materials. The first gate oxide material has a higher dielectric constant than the second gate oxide material. The first gate oxide material is formed to be over source/drain extension regions of the device; and the second gate oxide material is formed over a channel region of the device. The first gate oxide material has a low dielectric constant and provides for mitigating gate fringing field effects. The second gate oxide material has a high dielectric constant and provides for forming a thick gate oxide over a channel region of the device. Controlled uniform growth of the second gate oxide material is facilitated because of the thickness thereof.
Inventors
- 👤 Zoran Krivokapic
- 👤 Srinath Krishnan
- 👤 Geoffrey Choh-Fei Yeap
- 👤 Matthew Buynoski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:38
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/202; H10P30/204; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/01342; H10D64/017; H10D64/018; H10D64/60; H10D64/66; H10D64/671; H10D64/675; H10D64/68; H10D64/681; H10D64/683; H10D64/691; H10P30/208; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/517; H10D64/518
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
117 words
A method for fabricating a MOSFET device including the step of: forming a gate oxide including first and second gate oxide materials, the first gate oxide material having a dielectric constant of about ε<100 and the second gate oxide material having a dielectric constant of about ε>100 and a higher dielectric constant than the first gate oxide, the step of forming the gate oxide including the steps of: forming the first gate oxide material over source/drain extension regions of the device; etching a portion of the first gate oxide material between the source/drain extension regions of the device; and replacing said etched portion by forming the second gate oxide material over a channel region of the device.
Claim 2
Independent Claim
117 words
A method for fabricating a MOSFET device including the step of: forming a gate oxide including first and second gate oxide materials, the first gate oxide material having a dielectric constant of about ε<100 and the second gate oxide material having a dielectric constant of about ε>100 and a higher dielectric constant than the first gate oxide, the step of forming the gate oxide including the steps of: forming the first gate oxide material over source/drain extension regions of the device; etching a portion of the first gate oxide material between the source/drain extension regions of the device; and replacing said etched portion by forming the second gate oxide material over a channel region of the device.
Claim 3
Dependent Claim
18 words
The method of claim 1, wherein the first gate oxide material has a thickness of about <40 Å.
Claim 4
Dependent Claim
17 words
The method of claim 1, wherein the second gate oxide material has about a thickness >300 Å.
Claim 5
Dependent Claim
28 words
The method of claim 1, wherein the first gate oxide material is selected from a group comprising: SiO 2 and Si 3 N 4 , and combinations thereof.
Claim 6
Dependent Claim
38 words
The method of claim 1, wherein the second gate oxide material is selected from a group comprising: Al 2 O 3 ; Ta 2 O 5 ; TiO 2 ; SrTiO 3 ; ZnO; PZT, and combinations thereof.
Claim 7
Dependent Claim
14 words
The method of claim 1 further including the step of forming a dummy gate.
Claim 8
Dependent Claim
11 words
The method of claim 6, wherein the dummy gate comprises nitride.
Claim 9
Independent Claim
99 words
A method of fabricating a MOS transistor, comprising the steps of: providing a substrate having isolating regions thereon; forming a dummy gate structure over a portion of a first gate oxide material; implanting indium into a n-well region; implanting the well region to form lightly doped active regions; forming spacers along sidewalls of the dummy gate; implanting the well region to form source and drain regions; etching the dummy gate; etching a portion of the first gate oxide material that was under the dummy gate; and forming a second gate oxide material over a channel region of the transistor.
Claim 10
Independent Claim
99 words
A method of fabricating a MOS transistor, comprising the steps of: providing a substrate having isolating regions thereon; forming a dummy gate structure over a portion of a first gate oxide material; implanting indium into a n-well region; implanting the well region to form lightly doped active regions; forming spacers along sidewalls of the dummy gate; implanting the well region to form source and drain regions; etching the dummy gate; etching a portion of the first gate oxide material that was under the dummy gate; and forming a second gate oxide material over a channel region of the transistor.
Claim 11
Dependent Claim
90 words
The method of claim 8, wherein the first gate oxide material has a dielectric constant of about ε<100, has about a thickness <40 Å, and is selected from a group comprising: SiO 2 and Si 3 N 4 , and combinations thereof; and wherein the second gate oxide material has a dielectric constant of about ε>100, has about a thickness >300 Å, and is selected from a group comprising: Al 2 O 3 ; Ta 2 O 5 ; TiO 2 ; SrTiO 3 ; ZnO; PZT, and combinations thereof.
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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) | 2003-07-11 | 2004-01-10 | 2004-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-07-11 | 2008-01-10 | 2008-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-07-11 | 2012-01-10 | 2012-07-11 | $7700.00 | Window Closed / Lapsed |