US5793090A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated circuit having multiple LDD and/or source/drain implant steps to enhance circuit performance
Assignee: GlobalFoundries Inc
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Filing: 1997-01-10
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Granted: 1998-08-11
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Expires: 2017-01-10
Abstract
Abstract An integrated circuit is formed whereby MOS transistor junctions are produced which enhance the overall speed of the integrated circuit. The transistor junctions include multiple implants into the lightly doped drain (LDD) areas of the junction, the source/drain areas of the junction or both the LDD and source/drain areas. The first implant of the multiple implants serves to condition the implant area so that the second and subsequent implants are accurately placed with relatively high concentrations closely below the substrate surface. The resulting junction is therefore one which has relatively high drive strength, low contact resitivity, low source-to-drain parasitic resistance, and relatively low junction capacitance.
Inventors
- 👤 Mark I. Gardner
- 👤 Fred N. Hause
- 👤 H. Jim Fulford, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:45
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H10D30/60; H10D30/601; H10D30/603
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
102 words
An integrated circuit, comprising: a gate conductor laterally defined between a pair of sidewall surfaces a dielectric spaced distance above a semiconductor substrate; a first implant aligned with the sidewall surfaces, said first implant comprising a plurality of first dopant species arranged within the semiconductor substrate at a first concentration and a first concentration peak density; and a second implant aligned with the sidewall surfaces, said second implant comprising a plurality of second dopant species arranged within the semiconductor substrate at a second concentration greater than the first concentration and a second concentration peak density shallower than the first concentration peak density.
Claim 2
Dependent Claim
102 words
An integrated circuit, comprising: a gate conductor laterally defined between a pair of sidewall surfaces a dielectric spaced distance above a semiconductor substrate; a first implant aligned with the sidewall surfaces, said first implant comprising a plurality of first dopant species arranged within the semiconductor substrate at a first concentration and a first concentration peak density; and a second implant aligned with the sidewall surfaces, said second implant comprising a plurality of second dopant species arranged within the semiconductor substrate at a second concentration greater than the first concentration and a second concentration peak density shallower than the first concentration peak density.
Claim 3
Dependent Claim
26 words
The integrated circuit as recited in claim 1, wherein said gate conductor serves as an implant mask for said plurality of first and second dopant species.
Claim 4
Dependent Claim
20 words
The integrated circuit as recited in claim 1, wherein said plurality of first and second dopant species comprises n-type species.
Claim 5
Dependent Claim
20 words
The integrated circuit as recited in claim 1, wherein said plurality of first and second dopant species comprises p-type species.
Claim 6
Dependent Claim
32 words
The integrated circuit as recited in claim 1, wherein said plurality of first dopant species comprises atomic material of dissimilar chemical composition and atomic weight than the plurality of second dopant species.
Claim 7
Dependent Claim
36 words
The integrated circuit as recited in claim 1, wherein said plurality of first and second dopant species are forwarded into said semiconductor substrate at an acute angle relative to an upper surface of the semiconductor substrate.
Claim 8
Dependent Claim
23 words
The integrated circuit as recited in claim 6, wherein said acute angle comprises a range between approximately 45 degrees to approximately 83 degrees.
Claim 9
Dependent Claim
55 words
The integrated circuit as recited in claim 1, further comprises a third implant aligned with the sidewall surfaces, said third implant comprising a plurality of third dopant species arranged within the semiconductor substrate at a third concentration greater than the first concentration and a third concentration peak density shallower than the first concentration peak density.
Claim 10
Dependent Claim
37 words
The integrated circuit as recited in claim 8, wherein said third concentration is substantially identical to said second concentration and said third concentration peak density is at substantially the same depth as said second concentration peak density.
Claim 11
Dependent Claim
109 words
The integrated circuit as recited in claim 1, further comprising: a spacer extending laterally from the pair of sidewall surfaces to form a pair of outer sidewall surfaces; a third implant aligned with the outer sidewall surfaces, said third implant comprising a plurality of third dopant species arranged within the semiconductor substrate at a third concentration and a third concentration peak density; and a fourth implant aligned with the outer sidewall surfaces, said fourth implant comprising a plurality of fourth dopant species arranged within the semiconductor substrate at a fourth concentration greater than the third concentration and a fourth concentration peak density shallower than the third concentration peak density.
Claim 12
Dependent Claim
20 words
The integrated circuit as recited in claim 10, wherein said first, second, third and fourth dopant species comprise n-type species.
Claim 13
Dependent Claim
20 words
The integrated circuit as recited in claim 10, wherein said first, second, third and fourth dopant species comprise p-type species.
Claim 14
Dependent Claim
32 words
The integrated circuit as recited in claim 10, wherein said plurality of third dopant species comprise atomic material of dissimilar chemical composition and atomic weight than the plurality of fourth dopant species.
Claim 15
Dependent Claim
36 words
The integrated circuit as recited in claim 10, wherein said plurality of third and fourth dopant species are forwarded into said semiconductor substrate at an acute angle relative to an upper surface of the semiconductor substrate.
Claim 16
Dependent Claim
23 words
The integrated circuit as recited in claim 14, wherein said acute angle comprises a range between approximately 45 degrees to approximately 83 degrees.
Claim 17
Dependent Claim
108 words
An integrated circuit, comprising: a semiconductor topography; a gate conductor extending across the semiconductor topography; a lightly doped drain (LDD) area defined within said semiconductor topography substantially adjacent said gate conductor, said LDD area having at least one region of heavy dopant concentration formed at a shallower depth than a region of light dopant concentration also defined within the LDD area; and a source/drain area defined within said semiconductor topography a spaced distance away from the gate conductor, said source/drain area having at least one region of heavy dopant concentration formed at a shallower depth than a region of light dopant concentration also defined within the source/drain area.
Claim 18
Dependent Claim
108 words
An integrated circuit, comprising: a semiconductor topography; a gate conductor extending across the semiconductor topography; a lightly doped drain (LDD) area defined within said semiconductor topography substantially adjacent said gate conductor, said LDD area having at least one region of heavy dopant concentration formed at a shallower depth than a region of light dopant concentration also defined within the LDD area; and a source/drain area defined within said semiconductor topography a spaced distance away from the gate conductor, said source/drain area having at least one region of heavy dopant concentration formed at a shallower depth than a region of light dopant concentration also defined within the source/drain area.
Claim 19
Dependent Claim
49 words
The integrated circuit as recited in claim 16, wherein said region of heavy dopant concentration within both the LDD area and the source/drain area comprises dopant species of similar type to dopant species within said region of light dopant concentration within respective said LDD area and said source/drain area.
Claim 20
Dependent Claim
73 words
The integrated circuit as recited in claim 16, wherein said region of heavy dopant concentration within the LDD area comprises dopant species of dissimilar atomic composition to dopant species within said region of light dopant concentration within the LDD area, and wherein said region of heavy dopant concentration within the source/drain area comprises dopant species of dissimilar atomic composition to dopant species within the region of light dopant concentration within the source/drain area.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-08-10 | 2002-02-09 | 2002-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-10 | 2006-02-09 | 2006-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-10 | 2010-02-09 | 2010-08-11 | $7700.00 | Window Closed / Lapsed |