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Patent US6063677A successfully refreshed from Google Patents.
US6063677A
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Method of forming a MOSFET using a disposable gate and raised source and drain
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 transistor (100) using a disposable gate (120). A disposable gate (120) having at least two materials (122,124) that may be etched selectively with respect to each other is formed on a semiconductor substrate (102). Source/drain regions (104) are then formed adjacent the disposable gate. The source/drain regions may, for example, include raised source/drain regions (106). An insulator layer (114) is then deposited over the structure and then a portion of the insulator layer (114) over the disposable gate (120) is removed (e.g., using CMP or an etch-back). The composition of the insulator layer (114) is chosen such that the top layer (124) of the disposable gate (120) may be removed selectively with respect to the insulator layer (114). The disposable gate (120) is then removed and a channel implant may be performed that is self-aligned and only in the channel region. The gate dielectric (110) and gate electrode (112) are then formed.
Inventors
- 👤 Mark S. Rodder
- 👤 Richard A. Chapman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:05
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/20; H10D64/23; H10D64/251; H10D64/258; H10D64/259; H10D64/01; H10D64/017; H10D30/00; H10D30/01; H10D30/021; H10D30/0217; H10D30/0223; H10D30/027; H10D30/0275; H10D84/00; H10D84/01; H10D84/0123; H10D84/0126; H10D84/0135; H10P; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/1414; H10P32/17; H10P32/171
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
176 words
A method of forming a transistor comprising the steps of: forming a disposable gate on a defined channel region of a substrate, said disposable gate comprising at least two distinct materials; forming a source/drain region adjacent said disposable gate; forming an insulator layer over said source/drain region; selectively removing one of said at least two distinct materials without substantially removing another of said at least two distinct materials; removing a remainder of said disposable gate; forming a gate dielectric over said defined channel region after removing said remainder of said disposable gate; forming a gate electrode over said gate dielectric and a portion of said insulator layer, wherein said forming the gate electrode step comprises the steps of: depositing at least one conductive material over said gate dielectric and said insulator layer; removing a portion of said at least one conductive material so that said at least one conductive material is planarized with said insulator layer; and forming a top conductive material over said at least one conductive material and a portion of the insulator layer.
Claim 2
Independent Claim
176 words
A method of forming a transistor comprising the steps of: forming a disposable gate on a defined channel region of a substrate, said disposable gate comprising at least two distinct materials; forming a source/drain region adjacent said disposable gate; forming an insulator layer over said source/drain region; selectively removing one of said at least two distinct materials without substantially removing another of said at least two distinct materials; removing a remainder of said disposable gate; forming a gate dielectric over said defined channel region after removing said remainder of said disposable gate; forming a gate electrode over said gate dielectric and a portion of said insulator layer, wherein said forming the gate electrode step comprises the steps of: depositing at least one conductive material over said gate dielectric and said insulator layer; removing a portion of said at least one conductive material so that said at least one conductive material is planarized with said insulator layer; and forming a top conductive material over said at least one conductive material and a portion of the insulator layer.
Claim 3
Dependent Claim
55 words
The method of claim 1, wherein the step of forming said gate electrode comprises the steps of: depositing at least one conductive material over said gate dielectric and said insulator layer; and patterning and etching said at least one conductive material to form said gate electrode that extends over a portion of said insulator layer.
Claim 4
Dependent Claim
44 words
The method of claim 1, wherein said step of forming the top conductive material comprises the step of: growing an epitaxial layer by selective epitaxy on said at least one conductive material, wherein said epitaxial layer extends over a portion of said insulator layer.
Claim 5
Dependent Claim
47 words
The method of claim 1, wherein said step of forming the top conductive material comprises the step of: depositing, patterning and etching the top conductive material so that the top conductive material extends over said at least one conductive material and a portion of said insulator layer.
Claim 6
Dependent Claim
14 words
The method of claim 1, further comprising the step of cladding said gate electrode.
Claim 7
Dependent Claim
22 words
The method of claim 1, wherein said step of forming a source/drain region comprises the step of forming a raised source/drain region.
Claim 8
Dependent Claim
28 words
The method of claim 6, wherein the step of forming a source/drain region further comprises the step of diffusing dopant from said raised source/drain region into said substrate.
Claim 9
Dependent Claim
32 words
The method of claim 6, wherein the step of forming a source/drain region further comprises the step of cladding said raised source/drain regions prior to said step of forming said gate dielectric.
Claim 10
Dependent Claim
35 words
The method of claim 1, further comprising the step of performing a self-aligned introduction of channel dopants after said step of forming said source/drain region and prior to said step of forming a gate dielectric.
Claim 11
Dependent Claim
29 words
The method of claim 1, wherein said one of said at least two distinct materials comprises a nitride, another of said at least two distinct materials comprises an oxide.
Claim 12
Dependent Claim
37 words
The method of claim 1, wherein said one of said at least two distinct materials comprises a oxide, another of said at least two distinct materials comprises silicon-germanium or silicon, and said insulator layer comprises an oxide.
Claim 13
Independent Claim
93 words
A method of forming a MOSFET comprising the steps of: forming a disposable gate structure over a defined channel region of a substrate; forming a raised source/drain region by selective epitaxy adjacent said disposable gate structure, using said disposable gate structure as a mask; forming a dielectric layer over said raised source/drain region and said disposable gate structure; removing a portion of said dielectric layer to expose said disposable gate structure; removing said disposable gate structure; forming a gate dielectric over said defined channel region; forming a gate electrode over said gate dielectric.
Claim 14
Independent Claim
93 words
A method of forming a MOSFET comprising the steps of: forming a disposable gate structure over a defined channel region of a substrate; forming a raised source/drain region by selective epitaxy adjacent said disposable gate structure, using said disposable gate structure as a mask; forming a dielectric layer over said raised source/drain region and said disposable gate structure; removing a portion of said dielectric layer to expose said disposable gate structure; removing said disposable gate structure; forming a gate dielectric over said defined channel region; forming a gate electrode over said gate dielectric.
Claim 15
Dependent Claim
12 words
The method of claim 12, wherein said raised source/drain region is insitu-doped.
Claim 16
Dependent Claim
21 words
The method of claim 12, further comprising the step of diffusing a dopant from said raised source/drain region into said substrate.
Claim 17
Dependent Claim
24 words
The method of claim 12, further comprising the step of cladding said raised source/drain region prior to said step of forming said gate dielectric.
Claim 18
Dependent Claim
41 words
The method of claim 12, further comprising the step of performing a self-aligned introduction of channel dopants into said defined channel region after said step of forming said raised source/drain regions and prior to said step of forming a gate dielectric.
Claim 19
Dependent Claim
17 words
The method of claim 12, wherein said gate electrode extends over a portion of said dielectric layer.
Claim 20
Dependent Claim
18 words
The method of claim 12, wherein said gate electrode comprises a doped non-crystalline material comprised substantially of silicon.
Claim 21
Dependent Claim
11 words
The method of claim 12, wherein said gate electrode is cladded.
Claim 22
Dependent Claim
18 words
The method of claim 12, wherein said gate electrode comprises a metal layer and a doped polysilicon layer.
Claim 23
Dependent Claim
18 words
The method of claim 12, wherein said gate electrode comprises a metal layer and a titanium nitride layer.
Claim 24
Dependent Claim
35 words
The method of claim 12, wherein said gate electrode extends over a portion of said raised source/drain region, said gate electrode separated from said portion of the raised source/drain region only by said gate dielectric.
Claim 25
Dependent Claim
26 words
The method of claim 12, wherein said raised source/drain region comprises a material selected from the group consisting of a semiconductor, a metal, and a silicide.
Claim 26
Independent Claim
109 words
A method of forming a MOSFET comprising the steps of: forming a disposable gate over a defined channel region in a substrate; forming a source/drain region adjacent said disposable gate, wherein said source/drain region is a raised source/drain region formed by selective epitaxy; forming a dielectric layer over said source/drain region; removing a portion of said dielectric layer to expose said disposable gate; removing said disposable gate; forming a thin gate dielectric having a thickness less than 30 Å over at least a portion of said defined channel region; forming a gate electrode over said thin gate dielectric, wherein said gate electrode comprises a doped non-crystalline material comprising silicon.
Claim 27
Independent Claim
109 words
A method of forming a MOSFET comprising the steps of: forming a disposable gate over a defined channel region in a substrate; forming a source/drain region adjacent said disposable gate, wherein said source/drain region is a raised source/drain region formed by selective epitaxy; forming a dielectric layer over said source/drain region; removing a portion of said dielectric layer to expose said disposable gate; removing said disposable gate; forming a thin gate dielectric having a thickness less than 30 Å over at least a portion of said defined channel region; forming a gate electrode over said thin gate dielectric, wherein said gate electrode comprises a doped non-crystalline material comprising silicon.
Claim 28
Dependent Claim
15 words
The method of claim 24, wherein said disposable gate comprises at least two distinct materials.
Claim 29
Dependent Claim
23 words
The method of claim 24, wherein at least one of said at least two materials is removed without substantially removing said dielectric layer.
Claim 30
Dependent Claim
13 words
The method of claim 24, wherein said raised source/drain region is insitu doped.
Claim 31
Dependent Claim
28 words
The method of claim 24, wherein said step of forming said source/drain region further comprises the step of diffusing dopant from said raised source/drain region into said substrate.
Claim 32
Dependent Claim
24 words
The method of claim 24, further comprising the step of siliciding said source/drain region prior to said step of forming said thin gate dielectric.
Claim 33
Dependent Claim
14 words
The method of claim 24, further comprising the step of siliciding said gate electrode.
Claim 34
Dependent Claim
30 words
The method of claim 24, further comprising the step of performing a self-aligned introduction of channel dopants into said defined channel region after said step of forming said source/drain region.
Claim 35
Dependent Claim
35 words
The method of claim 24, wherein said gate electrode extends over a portion of said raised source/drain region, said gate electrode separated from said portion of the raised source/drain region only by said gate dielectric.
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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 |