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US6797556B2 Expired / Lapsed US ⏱️ 0.0 years remaining

MOS transistor structure and method of fabrication

Assignee: Intel Corp
•
Filing: 2003-01-07
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Granted: 2004-09-28
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Expires: 2023-01-07
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Abstract

Abstract An MOS device comprising a gate dielectric formed on a first conductivity type region. A gate electrode formed on the gate dielectric. A pair of sidewall spacers are formed along laterally opposite sidewalls of the gate electrode. A pair of deposited silicon or silicon alloy source/drain regions are formed in the first conductivity region and on opposite sides of a gate electrode wherein the silicon or silicon alloy source/drain regions extend beneath the gate electrode and to define a channel region beneath the gate electrode in the first conductivity type region wherein the channel region directly beneath the gate electrode is larger than the channel region deeper into said first conductivity type region.

Inventors

  • 👤 Anand Murthy
  • 👤 Robert S. Chau
  • 👤 Patrick Morrow

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 22:35
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/027; H10D30/0275; H10D30/0212; H10D62/00; H10D62/01; H10D62/021; H10D62/10; H10D62/17; H10D62/213; H10D62/221; H10D62/235; H10D62/299; H10D62/307; H10D62/351; H10D62/357; H10D62/364; H10D62/371; H10D62/80; H10D62/83; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01306; H10D64/01308; H10D64/0131; H10D64/60; H10D64/62; H10D64/66; H10D64/661; H10D64/662; H10D64/663; H10D62/82; H10D62/822; H10D64/021

Claims Analysis

Total Claims: 24
Claim 1
Independent Claim 135 words
A method of forming an device comprising: forming a gate dielectric on a first conductivity type region; forming a gate electrode on said gate dielectric; forming a pair of sidewall spacers along laterally opposite sidewalls of said gate electrode; and forming a pair of recesses on opposite sides of said gate electrode; depositing a silicon or silicon alloy into said pair of recesses to form a pair of source/drain regions of a second conductivity type in said substrate on opposite sides of said gate electrode, wherein said silicon or silicon alloy source/drain regions extend beneath the gate electrode and define a channel region beneath said gate electrode in said first conductivity type region wherein said channel region directly beneath the gate electrode is large than said channel region deeper into said first conductivity type region.
Claim 2
Independent Claim 135 words
A method of forming an device comprising: forming a gate dielectric on a first conductivity type region; forming a gate electrode on said gate dielectric; forming a pair of sidewall spacers along laterally opposite sidewalls of said gate electrode; and forming a pair of recesses on opposite sides of said gate electrode; depositing a silicon or silicon alloy into said pair of recesses to form a pair of source/drain regions of a second conductivity type in said substrate on opposite sides of said gate electrode, wherein said silicon or silicon alloy source/drain regions extend beneath the gate electrode and define a channel region beneath said gate electrode in said first conductivity type region wherein said channel region directly beneath the gate electrode is large than said channel region deeper into said first conductivity type region.
Claim 3
Dependent Claim 46 words
The method of claim 1 further comprising: depositing said silicon or silicon alloy above said gate dielectric such that the top surface of said silicon or silicon alloy is spaced further from said gate electrode then the silicon or silicon alloy adjacent to said gate dielectric.
Claim 4
Dependent Claim 36 words
The method of forming an MOS device at claim 1 further comprising: making the outside edge of said gate dielectric beneath said gate electrode thicker than the gate dielectric beneath the center of said gate electrode.
Claim 5
Independent Claim 98 words
A method of forming a transistor comprising: forming a gate dielectric layer on a first surface of a first conductivity type region of a substrate; forming a gate electrode having laterally opposite sidewalls on said gate dielectric; forming a pair of sidewall spacers along laterally opposite sidewalls of said gate electrode; etching a pair of recesses in said substrate on opposite sides of said gate electrode wherein said etching of said substrate forms a pair of recesses having an inflection point beneath said gate electrode; and depositing a silicon or silicon alloy film into said pair of recesses.
Claim 6
Independent Claim 98 words
A method of forming a transistor comprising: forming a gate dielectric layer on a first surface of a first conductivity type region of a substrate; forming a gate electrode having laterally opposite sidewalls on said gate dielectric; forming a pair of sidewall spacers along laterally opposite sidewalls of said gate electrode; etching a pair of recesses in said substrate on opposite sides of said gate electrode wherein said etching of said substrate forms a pair of recesses having an inflection point beneath said gate electrode; and depositing a silicon or silicon alloy film into said pair of recesses.
Claim 7
Dependent Claim 28 words
The method of claim 4 , wherein said etching of said recesses exposes a portion of said gate dielectric layer beneath the outside edges of said gate electrode.
Claim 8
Dependent Claim 29 words
The method of claim 4 further comprising oxidizing said exposed portion of said gate dielectric layer to increase the thickness of said exposed portions of said gate dielectric layer.
Claim 9
Dependent Claim 53 words
The method of claim 4 further comprising etching said recess to expose a portion of said gate dielectric layer beneath the outside edges of said gate electrode and wherein said etching oxidizes said exposed portion of said gate dielectric layer to increase the thickness of said exposed portion of said gate dielectric layer.
Claim 10
Dependent Claim 14 words
The method of claim 4 wherein said etching utilizes an isotropic dry etching process.
Claim 11
Dependent Claim 12 words
The method of claim 8 wherein said etching comprises SF6 and He.
Claim 12
Dependent Claim 22 words
The method of claim 4 further comprising depositing said silicon or silicon alloy film above said first surface of said semiconductor substrate.
Claim 13
Dependent Claim 52 words
The method of claim 10 wherein said silicon or silicon alloy film is deposited above said first surface of said semiconductor substrate such that the top surface of said deposited silicon or silicon alloy is spaced further from said gate electrode than the silicon or silicon alloy adjacent to said gate dielectric.
Claim 14
Dependent Claim 36 words
The method of claim 10 wherein said silicon or silicon alloy film is deposited above said first surface in such a manner to create a through (311) facet in said deposited silicon or silicon alloy film.
Claim 15
Dependent Claim 19 words
The method of claim 4 wherein said deposited silicon or silicon alloy film is doped during said deposition process.
Claim 16
Dependent Claim 29 words
The method of claim 13 wherein said deposited silicon or silicon alloy film is doped to a second conductivity type opposite said first conductivity type during said deposition process.
Claim 17
Dependent Claim 59 words
The method of claim 4 wherein said silicon or silicon alloy deposition process comprises a first deposition process which forms a silicon or silicon alloy film doped to said first conductivity type and a second silicon or silicon alloy deposition process which dopes said silicon or silicon alloy film to a second conductivity type opposite said first conductivity type.
Claim 18
Independent Claim 106 words
A method of forming a transistor comprising: forming a gate dielectric layer on a first surface of a first conductivity type region of a substrate; forming a gate electrode having laterally opposite sidewalls on said gate dielectric layer; forming a pair of sidewall spacers along laterally opposite sidewalls of said gate electrode; etching a pair of recesses in said substrate on opposite sides of said gate electrode, wherein said etching exposes said gate dielectric beneath the laterally opposite sidewalls of said gate electrode; increasing the thickness of said exposed portion of said gate dielectric layer; and depositing a silicon or silicon alloy film in said recesses.
Claim 19
Independent Claim 106 words
A method of forming a transistor comprising: forming a gate dielectric layer on a first surface of a first conductivity type region of a substrate; forming a gate electrode having laterally opposite sidewalls on said gate dielectric layer; forming a pair of sidewall spacers along laterally opposite sidewalls of said gate electrode; etching a pair of recesses in said substrate on opposite sides of said gate electrode, wherein said etching exposes said gate dielectric beneath the laterally opposite sidewalls of said gate electrode; increasing the thickness of said exposed portion of said gate dielectric layer; and depositing a silicon or silicon alloy film in said recesses.
Claim 20
Dependent Claim 35 words
The method of claim 16 wherein said pair of recesses are etched with an oxidizing etchant which oxidizes said gate electrode to further increase the thickness of said exposed portion of said gate dielectric layer.
Claim 21
Dependent Claim 20 words
The method of claim 16 wherein said etching of said pair of recesses forms inflection points beneath said gate electrode.
Claim 22
Dependent Claim 18 words
The method of claim 16 wherein said pair of recesses are etched utilizing an isotropic dry etching process.
Claim 23
Dependent Claim 12 words
The method of claim 19 wherein said etching comprises SF6 and He.
Claim 24
Dependent Claim 50 words
The method claim 18 further comprising depositing said silicon or silicon alloy above said first surface of said semiconductor substrate such that the top surface of said deposited silicon or silicon alloy is spaced further from said gate electrode than the silicon or silicon alloy adjacent to said gate dielectric.

References Cited (Backward Citations)

US5970351A Cited
US5824587A Cited
US6057582A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2007-09-28 2008-03-29 2008-09-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2011-09-28 2012-03-29 2012-09-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2015-09-28 2016-03-29 2016-09-28 $7700.00 Window Closed / Lapsed

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