US5587604A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Contacted body silicon-on-insulator field effect transistor
Assignee: GlobalFoundries Inc
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Filing: 1994-09-22
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Granted: 1996-12-24
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Expires: 2014-09-22
Abstract
Abstract Structures and methods are presented for forming a body-substrate connector for an SOI FET. The connector is formed substantially co-aligned with the gate conductor on a side of the device that does not interfere with source and drain. The body is thus held close to the substrate potential and the connector provides a path for majority carriers to quickly leave the body. By contacting the body of the SOI MOSFET device in a manner that does not perturb the charge imaged by the gate, parasitic bipolar effects are eliminated while maintaining the desirable attributes of SOI MOSFET devices, such as low substrate bias sensitivity and steep sub-threshold slope. By forming the connector substantially co-aligned with the gate conductor the connection uses little or no surface area.
Inventors
- 👤 Brian J. Machesney
- 👤 Jack A. Mandelman
- 👤 Edward J. Nowak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:28
CPC Classifications
H; H10; H10D; H10D86/00; H10D86/201; Y; Y10; Y10S; Y10S148/00; Y10S148/15; Y10S438/00; Y10S438/98
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
130 words
A semiconductor structure comprising: a semiconductor substrate having a buried dielectric defining lower and upper regions of said substrate, said upper region being monocrystalline; an FET comprising a gate dielectric located on a portion of said upper region of said substrate; a gate located above said gate dielectric, said gate having a first side, a second side, and a third side; and a source diffusion and a drain diffusion within said upper region, said source diffusion along said first side, said drain diffusion along said second side; and an electrical connection between said upper region and said lower region, said connection having an edge substantially co-aligned with said third side of said gate, there being no mask alignment tolerance spacing between said connection and said third side of said gate.
Claim 2
Dependent Claim
130 words
A semiconductor structure comprising: a semiconductor substrate having a buried dielectric defining lower and upper regions of said substrate, said upper region being monocrystalline; an FET comprising a gate dielectric located on a portion of said upper region of said substrate; a gate located above said gate dielectric, said gate having a first side, a second side, and a third side; and a source diffusion and a drain diffusion within said upper region, said source diffusion along said first side, said drain diffusion along said second side; and an electrical connection between said upper region and said lower region, said connection having an edge substantially co-aligned with said third side of said gate, there being no mask alignment tolerance spacing between said connection and said third side of said gate.
Claim 3
Dependent Claim
24 words
An FET as recited in claim 1, wherein said connection is spaced from said third side by a distance of 10 to 200 nm.
Claim 4
Dependent Claim
28 words
An FET as recited in claim 2, wherein at least a portion of said distance is provided by one of a spacer and an straggle of an implant.
Claim 5
Dependent Claim
54 words
An FET as recited in claim 1, wherein said gate has an electric field that varies with position when said FET is in operation and wherein said connection to a portion of said upper region is in a position in which the electric field is substantially smaller than the electric field under said gate.
Claim 6
Dependent Claim
21 words
An FET as recited in claim 1, wherein said FET has a fully depleted body when in a normal operation state.
Claim 7
Dependent Claim
22 words
An FET as recited in claim 1, wherein said upper region has a thickness in the range 5 nm to 500 nm.
Claim 8
Dependent Claim
24 words
An FET as recited in claim 1, further comprising an insulation above said electrical connection, said insulation being substantially thicker than said gate dielectric.
Claim 9
Dependent Claim
13 words
An FET as recited in claim 7, wherein said insulation is a oxide.
Claim 10
Dependent Claim
14 words
An FET as recited in claim 1, wherein said buried dielectric is silicon dioxide.
Claim 11
Dependent Claim
19 words
An FET as recited in claim 1, wherein said buried dielectric is a horizontal trench lined with an insulator.
Claim 12
Dependent Claim
24 words
An FET as recited in claim 10, wherein a vertical trench intersects said horizontal trench and said vertical trench is lined with said insulator.
Claim 13
Dependent Claim
16 words
An FET as recited in claim 1, wherein said buried dielectric has two approximately vertical sidewalls.
Claim 14
Dependent Claim
18 words
An FET as recited in claim 1, wherein said connection is one of monocrystalline silicon and polycrystalline silicon.
Claim 15
Dependent Claim
18 words
An FET as recited in claim 13, wherein said silicon extends over an insulating spacer along a sidewall.
Claim 16
Dependent Claim
23 words
An FET as recited in claim 1, wherein said buried dielectric, said connection, and said third side of said FET are substantially co-aligned.
Claim 17
Dependent Claim
21 words
An FET as recited in claim 10, wherein said connection is monocrystalline semiconductor extending around an edge of said horizontal trench.
Claim 18
Dependent Claim
14 words
An FET as recited in claim 16, wherein said connection is single crystal silicon.
Claim 19
Dependent Claim
15 words
An FET as recited in claim 1, wherein said buried dielectric has a rounded sidewall.
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) | 1999-12-24 | 2000-06-24 | 2000-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-24 | 2004-06-24 | 2004-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-24 | 2008-06-24 | 2008-12-24 | $7700.00 | Window Closed / Lapsed |