US6063675A
Expired / Lapsed
US
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Method of forming a MOSFET using a disposable gate with a sidewall dielectric
Assignee: Texas Instruments Inc
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Filing: 1997-10-24
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Granted: 2000-05-16
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Expires: 2017-10-24
Abstract
Abstract A method for forming a MOSFET (200) using a disposable gate. A disposable gate (220) having at least two materials that may be etched selectively with respect to each other is formed on a substrate (202). A sidewall dielectric (215) is formed on the sidewalls of the disposable gate (220). The composition of the disposable gate materials (222,223, and 224) and the sidewall dielectric (215) are chosen such that the disposable gate (220) may be removed selectively with respect to the sidewall dielectric (215). A dielectric layer (214) is then deposited over the structure and a portion of the dielectric layer (214) is removed to expose the disposable gate (220) (e.g., using CMP or an etch-back). The composition of the dielectric layer (214) is chosen such that (1) the dielectric layer (214) may be removed selectively with respect to the sidewall dielectric (215) and (2) a layer of the disposable gate (220) may be removed selectively with respect to the dielectric layer (214). The disposable gate (220) is then removed and the gate dielectric (210) and gate electrode (212) are formed.
Inventors
- 👤 Mark S. Rodder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:28
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/13; H10D62/149; H10D62/151; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/027; H10D30/0273; H10D30/0275; H10D64/00; H10D64/01; H10D64/017; H10D64/20; H10D64/23; H10D64/251; H10D64/258; H10D64/259; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/517; H10D64/518; Y; Y10; Y10S; Y10S438/00; Y10S438/926
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
105 words
A method of forming a transistor comprising the steps of: forming a disposable gate over a defined channel region of a substrate; forming a sidewall dielectric adjacent said disposable gate; forming a source/drain region adjacent said sidewall dielectric; forming a dielectric layer over said source/drain region, said dielectric layer comprising a material that may be removed selectively with respect to said sidewall dielectric; selectively removing said disposable gate without substantially removing said sidewall dielectric; selectively removing said sidewall dielectric; forming a gate dielectric over said defined channel region, after said step of selectively removing said sidewall dielectric; forming a gate electrode over said gate dielectric.
Claim 2
Independent Claim
105 words
A method of forming a transistor comprising the steps of: forming a disposable gate over a defined channel region of a substrate; forming a sidewall dielectric adjacent said disposable gate; forming a source/drain region adjacent said sidewall dielectric; forming a dielectric layer over said source/drain region, said dielectric layer comprising a material that may be removed selectively with respect to said sidewall dielectric; selectively removing said disposable gate without substantially removing said sidewall dielectric; selectively removing said sidewall dielectric; forming a gate dielectric over said defined channel region, after said step of selectively removing said sidewall dielectric; forming a gate electrode over said gate dielectric.
Claim 3
Dependent Claim
33 words
The method of claim 1, wherein said step of forming a source/drain region comprises the steps of: forming a raised source/drain region; and diffusing dopant from said raised source/drain region into said substrate.
Claim 4
Dependent Claim
20 words
The method of claim 1, wherein said disposable gate comprises a first material layer and a distinct second material layer.
Claim 5
Dependent Claim
20 words
The method of claim 3, wherein said first material layer comprises oxide and said second material layer comprises silicon germanium.
Claim 6
Dependent Claim
19 words
The method of claim 3, wherein said first material layer comprises oxide and said second material layer comprises silicon.
Claim 7
Dependent Claim
20 words
The method of claim 3, wherein said disposable gate further comprises a third material layer above said second material layer.
Claim 8
Dependent Claim
40 words
The method of claim 6, wherein said first material layer comprises a dielectric, said second material layer comprises a semiconductor, said third material layer comprises a dielectric, said sidewall dielectric comprises a nitride, and said dielectric layer comprises an oxide.
Claim 9
Dependent Claim
10 words
The method of claim 7, wherein said semiconductor is silicon.
Claim 10
Dependent Claim
11 words
The method of claim 7, wherein said semiconductor is silicon germanium.
Claim 11
Dependent Claim
12 words
The method of claim 7, wherein said first material layer comprises oxide.
Claim 12
Dependent Claim
12 words
The method of claim 7, wherein said third material layer comprises nitride.
Claim 13
Dependent Claim
12 words
The method of claim 7, wherein said third material layer comprises oxide.
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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) | 2003-05-16 | 2003-11-15 | 2004-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-05-16 | 2007-11-15 | 2008-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-05-16 | 2011-11-15 | 2012-05-16 | $7700.00 | Window Closed / Lapsed |