Patent EP0799805A1 successfully refreshed from Google Patents.
Patent US6225151B1 successfully refreshed from Google Patents.
US6225151B1
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Nitrogen liner beneath transistor source/drain regions to retard dopant diffusion
Assignee: GlobalFoundries Inc
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Filing: 1997-06-09
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Granted: 2001-05-01
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Expires: 2017-06-09
Abstract
Abstract A nitrogen implanted region formed substantially below and substantially adjacent to a source/drain region of an IGFET forms a liner to retard the diffusion of the source/drain dopant atoms during a subsequent heat treatment operation such as an annealing step. The nitrogen liner may be formed by implantation of nitrogen to a given depth before the implantation of source/drain dopant to a lesser depth. Nitrogen may also be introduced into regions of the IGFET channel region beneath the gate electrode for retarding subsequent lateral diffusion of the source/drain dopant. Such nitrogen introduction may be accomplished using one or more angled implantation steps, or may be accomplished by annealing an implanted nitrogen layer formed using a perpendicular implant aligned to the gate electrode. The liner may be formed on the drain side of the IGFET or on both source and drain side, and may be formed under a lightly-doped region or under a heavily-doped region of the drain and/or source. Such a liner is particularly advantageous for boron-doped source/drain regions, and may be combined with N-channel IGFETs formed without such liners.
Inventors
- 👤 Mark I. Gardner
- 👤 Robert Dawson
- 👤 H. Jim Fulford, Jr.
- 👤 Frederick N. Hause
- 👤 Daniel Kadosh
- 👤 Mark W. Michael
- 👤 Bradley T. Moore
- 👤 Derick J. Wristers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:18
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/13; H10D62/149; H10D62/151; H10D30/00; H10D30/01; H10D30/021; H10D30/0221; H10D30/0223; H10D30/0227; H10D30/60; H10D30/601; H10D62/17; H10D62/213; H10D62/221; H10D62/235; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/01338; H10D64/01344; H10D64/60; H10D64/66; H10D64/68; H10D64/693; H10D84/00; H10D84/01; H10D84/0123; H10D84/0126; H10D84/0165; H10D84/017; H10D84/02; H10D84/03; H10D84/038; H10P; H10P30/00; H10P30/20; H10P30/22; H10P30/221; H10P30/222; H10P30/202; H10P30/204; H10P30/208; H10P30/21; H10P30/225; H10P30/28
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
129 words
In a semiconductor process, a method of forming an insulated-gate field effect transistor (IGFET), the method comprising the steps of: providing a semiconductor body having a top surface; forming a gate structure on the top surface; introducing a first dopant implant into the semiconductor body to form a first and a second source/drain region aligned with the gate structure for the IGFET; forming a liner substantially beneath the first source/drain region, the liner providing a thermal diffusion barrier for the dopant of the first source/drain region forming spacers beside the gate structure, and introducing a second dopant implant dopant into the first and the second source/drain regions aligned with the spacers and the gate structure, the second dopant extending the first and the second source/drain region beneath the liner.
Claim 2
Dependent Claim
129 words
In a semiconductor process, a method of forming an insulated-gate field effect transistor (IGFET), the method comprising the steps of: providing a semiconductor body having a top surface; forming a gate structure on the top surface; introducing a first dopant implant into the semiconductor body to form a first and a second source/drain region aligned with the gate structure for the IGFET; forming a liner substantially beneath the first source/drain region, the liner providing a thermal diffusion barrier for the dopant of the first source/drain region forming spacers beside the gate structure, and introducing a second dopant implant dopant into the first and the second source/drain regions aligned with the spacers and the gate structure, the second dopant extending the first and the second source/drain region beneath the liner.
Claim 3
Dependent Claim
18 words
The method as in claim 1 wherein the first dopant implant provides lightly-doped first and second source/drain regions.
Claim 4
Dependent Claim
18 words
The method as in claim 1 wherein the second dopant implant provides first and second heavily-doped source/drain regions.
Claim 5
Dependent Claim
20 words
The method as in claim 1 wherein the liner comprises a nitrogen liner formed by implantation of a nitrogen-containing material.
Claim 6
Dependent Claim
18 words
The method as in claim 1 wherein the liner forming step comprises an implantation of a carbon-containing material.
Claim 7
Dependent Claim
68 words
The method as in claim 1 further comprising the steps: introducing a third dopant implant into the semiconductor body prior to forming the spacers to form a shallow doped region in the first source/drain region; and forming a liner substantially beneath the first region of the second source/drain, to retard subsequent diffusion of dopant comprising the first source/drain region of the second source/drain aligned with the gate structure.
Claim 8
Dependent Claim
30 words
The method as in claim 1 comprising the step of: forming a second IGFET of opposite conductivity type as the particular conductivity type, said second IGFET formed without any liner.
Claim 9
Dependent Claim
54 words
The method as in claim 1 further comprising the step of: forming a second IGFET of opposite conductivity type as the particular conductivity type, said second IGFET including a liner formed substantially beneath a first region of a first source/drain, to retard subsequent diffusion of dopants comprising the first region of the first source/drain.
Claim 10
Dependent Claim
130 words
In a semiconductor process, a method of forming an insulated-gate field effect transistor (IGFET) the method comprising the steps of: providing a semiconductor body having a top surface; forming at least a portion of a gate structure on the top surface: introducing a first dopant implant into the semiconductor body to form lightly doped source/drain regions aligned with the gate structure for the IGFET; forming spacers on walls of the gate structure; introducing a second dopant implant to form source/drain regions extending beneath the lightly doped source drain regions and aligned with the gate structure and with the spacers; and forming a nitrogen liner substantially beneath the source/drain regions and generally aligned with the gate structure and the spacers, the nitrogen liner providing a thermal diffusion barrier for the dopant.
Claim 11
Dependent Claim
130 words
In a semiconductor process, a method of forming an insulated-gate field effect transistor (IGFET) the method comprising the steps of: providing a semiconductor body having a top surface; forming at least a portion of a gate structure on the top surface: introducing a first dopant implant into the semiconductor body to form lightly doped source/drain regions aligned with the gate structure for the IGFET; forming spacers on walls of the gate structure; introducing a second dopant implant to form source/drain regions extending beneath the lightly doped source drain regions and aligned with the gate structure and with the spacers; and forming a nitrogen liner substantially beneath the source/drain regions and generally aligned with the gate structure and the spacers, the nitrogen liner providing a thermal diffusion barrier for the dopant.
Claim 12
Dependent Claim
19 words
The method as in claim 9 wherein the source/drain region of the second dopant implant comprises a heavily-doped region.
Claim 13
Dependent Claim
27 words
The method as in claim 9 wherein the nitrogen liner is formed substantially adjacent to the source/drain region of the second dopant implant in a vertical direction.
Claim 14
Dependent Claim
27 words
The method as in claim 9 wherein the nitrogen liner is formed substantially spaced from the source/drain region of the second dopant implant in a vertical direction.
Claim 15
Dependent Claim
31 words
The method as in claim 9 wherein the nitrogen liner retards vertical diffusion of a dopant from the first and second dopant implants in a direction away from the top surface.
Claim 16
Dependent Claim
24 words
The method as in claim 9 wherein the nitrogen liner is formed by implanting nitrogen at an angle substantially perpendicular to the top surface.
Claim 17
Dependent Claim
81 words
In a semiconductor process, a method of forming an insulated-gate field effect transistor (IGFET), the method comprising the steps of: providing a semiconductor body having a top surface; introducing a dopant into the semiconductor body to form a source/drain region for the IGFET; and forming a nitrogen liner substantially beneath the source/drain region, the nitrogen liner providing a thermal diffusion barrier for the dopant wherein the nitrogen liner includes a portion which extends laterally beneath a gate electrode of the IGFET.
Claim 18
Dependent Claim
81 words
In a semiconductor process, a method of forming an insulated-gate field effect transistor (IGFET), the method comprising the steps of: providing a semiconductor body having a top surface; introducing a dopant into the semiconductor body to form a source/drain region for the IGFET; and forming a nitrogen liner substantially beneath the source/drain region, the nitrogen liner providing a thermal diffusion barrier for the dopant wherein the nitrogen liner includes a portion which extends laterally beneath a gate electrode of the IGFET.
Claim 19
Dependent Claim
44 words
The method as in claim 15 wherein the nitrogen liner retards vertical diffusion of the dopant in a direction away from the top surface of the semiconductor body, and further retards lateral diffusion of the dopant in a direction parallel to the top surface.
Claim 20
Dependent Claim
32 words
The method as in claim 15 wherein the portion of the nitrogen liner extending laterally beneath the gate electrode is formed by implanting nitrogen at an angle relative to the top surface.
Claim 21
Dependent Claim
25 words
The method as in claim 15 wherein the portion of the nitrogen liner extending laterally beneath the gate electrode extends up to the top surface.
Claim 22
Dependent Claim
44 words
The method as in claim 15 wherein the portion of the nitrogen liner extending laterally beneath the gate electrode is formed by a plurality of angled nitrogen implantation steps relative to the top surface, each performed in a different direction into the semiconductor body.
Claim 23
Dependent Claim
32 words
The method as in claim 19 wherein a portion of the nitrogen liner disposed beneath the source/drain region is formed by implanting nitrogen at an angle substantially perpendicular to the top surface.
Claim 24
Dependent Claim
20 words
The method as in claim 15 further comprising the step of forming a gate electrode disposed upon the semiconductor body.
Claim 25
Dependent Claim
18 words
The method as in claim 21 wherein the nitrogen liner is formed before the gate electrode is formed.
Claim 26
Dependent Claim
18 words
The method as in claim 21 wherein the nitrogen liner is formed after the gate electrode is formed.
Claim 27
Dependent Claim
108 words
In a semiconductor process, a method of forming a nitrogen liner for an insulated-gate field effect transistor (IGFET) comprising the steps of: providing a semiconductor body having a top surface; implanting nitrogen into the semiconductor body beneath a source region and a drain region of the IGFET, said nitrogen implanted to a first death below the top surface of the semiconductor body; and introducing a dopant within said source and drain regions of the IGFET, said having a depth less than the first depth; and introducing nitrogen into the semiconductor body within a portion of a channel region of the IGFET beneath a gate electrode of the IGFET.
Claim 28
Dependent Claim
108 words
In a semiconductor process, a method of forming a nitrogen liner for an insulated-gate field effect transistor (IGFET) comprising the steps of: providing a semiconductor body having a top surface; implanting nitrogen into the semiconductor body beneath a source region and a drain region of the IGFET, said nitrogen implanted to a first death below the top surface of the semiconductor body; and introducing a dopant within said source and drain regions of the IGFET, said having a depth less than the first depth; and introducing nitrogen into the semiconductor body within a portion of a channel region of the IGFET beneath a gate electrode of the IGFET.
Claim 29
Dependent Claim
26 words
The method as in claim 24 wherein the nitrogen introducing step includes: implanting nitrogen at an angle relative to the top surface of the semiconductor body.
Claim 30
Dependent Claim
50 words
The method as in claim 24 wherein the nitrogen introducing step includes the step of: annealing the nitrogen previously implanted into the semiconductor body beneath the source and drain regions, said annealing causing diffusion of the nitrogen, thereby extending a region containing the nitrogen to extend beneath the gate electrode.
Claim 31
Dependent Claim
29 words
The method as in claim 24 wherein the nitrogen introducing step includes the step of: implanting nitrogen through the gate electrode and into the channel region of the IGFET.
Claim 32
Dependent Claim
43 words
The method as in claim 24 further comprising the step of: introducing nitrogen into the semiconductor body with portions of a channel region of the IGFET beneath a gate electrode of the IGFET, said portions being adjacent to said source and drain regions.
Claim 33
Dependent Claim
32 words
The method as in claim 28 wherein the nitrogen introducing step includes the step of: implanting nitrogen using a plurality of angled implants relative to the top surface of the semiconductor body.
Claim 34
Dependent Claim
27 words
The method as in claim 29 wherein the plurality of angled implants comprises four separate angled implants, each performed in a different direction into the semiconductor body.
Claim 35
Dependent Claim
49 words
The method as in claim 28 wherein the nitrogen introducing step includes the step of: annealing the nitrogen previously implanted into the semiconductor body beneath the source and drain regions, said annealing causing diffusion of the nitrogen, thereby extending regions containing the nitrogen to extend beneath the gate electrode.
Claim 36
Dependent Claim
29 words
The method as in claim 28 wherein the nitrogen introducing step includes the step of: implanting nitrogen through the gate electrode and into the channel region of the IGFET.
Claim 37
Dependent Claim
33 words
The method as in claim 28 wherein the nitrogen introducing step includes the step of: implanting nitrogen into the channel region of the IGFET before formation of a gate electrode of the IGFET.
Claim 38
Dependent Claim
50 words
The method as in claim 32 wherein the step of implanting nitrogen into the semiconductor body beneath the source and drain regions of the IGFET, and the step of implanting nitrogen through the gate electrode and into the channel region of the IGFET, are performed in a single implantation step.
Claim 39
Dependent Claim
56 words
The method as in claim 32 wherein the step of implanting nitrogen into the semiconductor body beneath the source and drain regions of the IGFET, and the step of implanting nitrogen through the gate electrode and into the channel region of the IGFET, are performed using two different nitrogen implants each having a different implant energy.
Claim 40
Dependent Claim
56 words
The method as in claim 32 wherein the step of implanting nitrogen into the semiconductor body beneath the source and drain regions of the IGFET, and the step of implanting nitrogen through the gate electrode and into the channel region of the IGFET, are each performed using an atomic nitrogen implant or a molecular nitrogen implant.
Claim 41
Dependent Claim
26 words
The method as in claim 24 wherein the implanted nitrogen is chosen from the group consisting of molecular nitrogen (N 2 ) and atomic nitrogen (N).
References Cited (Backward Citations)
US3976511A
Cited
JPS61263274A
Cited
JPH0311731A
Cited
JPH0338839A
Cited
EP0419128A1
Cited
US5223445A
Cited
US5496751A
Cited
US5514902A
Cited
US5516707A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-04-30 | 2004-10-30 | 2005-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-04-30 | 2008-10-30 | 2009-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-04-30 | 2012-10-30 | 2013-05-01 | $7700.00 | Window Closed / Lapsed |