US5578865A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reduction of parasitic effects in floating body mosfets
Assignee: Callahan Cellular LLC
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Filing: 1995-04-24
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Granted: 1996-11-26
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Expires: 2015-04-24
Abstract
Abstract A semiconductor fabrication method improves the voltage characteristic of floating-body MOSFETs by creating recombination centers near the source-body junction of the device. A MOSFET is fabricated through the passivation oxidation stage, and a photolithography step is used to expose the source region. Implantation is then performed using one of two types of material. A first type creates electron traps of predetermined energy in the vicinity of the source-body junction. A second type creates defects in the crystalline structure of the semiconductor material. Both implantation types create recombination centers in the material. This allows the discharge through the source-body junction of charges built up in the body region.
Inventors
- 👤 Duy-Phach Vu
- 👤 Ngwe K. Cheong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 00:51
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3141; G; G02; G02B; G02B27/00; G02B27/0093; G09; G09G; G09G3/00; G09G3/20; G09G3/22; G09G3/30; G09G3/34; G09G3/36; H04N5/00; H04N5/74; H04N5/7416; H04N5/7441; H10; H10D; H10D86/00; H10D86/01; G09G2300/00; G09G2300/02; G09G2300/023; G09G2300/08; G09G2300/0809; G09G2300/0842; G09G2320/00; G09G2320/02; G09G2320/0233; G09G2320/04; G09G2320/041; G09G2320/043; G09G2340/00; G09G2340/04; G09G2340/0464; G09G2370/00; G09G2370/04; G09G2370/042; G09G3/3607; G09G3/3611; G09G3/3614; G09G3/3648; H04N5/66; H04N5/70; H04N5/7475; H04N5/7491
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
88 words
A floating-body MOSFET device comprising: a channel region of a first conductivity type formed in a silicon thin film over an insulating layer; a source region of a second conductivity type adjacent the channel region in the silicon thin film such that a p-n junction exists between the source region and the channel region; and a high concentration of recombination centers in the silicon and underlying the p-n junction relative to a concentration of recombination centers at a second junction between a drain region and the channel region.
Claim 2
Dependent Claim
88 words
A floating-body MOSFET device comprising: a channel region of a first conductivity type formed in a silicon thin film over an insulating layer; a source region of a second conductivity type adjacent the channel region in the silicon thin film such that a p-n junction exists between the source region and the channel region; and a high concentration of recombination centers in the silicon and underlying the p-n junction relative to a concentration of recombination centers at a second junction between a drain region and the channel region.
Claim 3
Dependent Claim
16 words
The floating-body MOSFET device of claim 1 further comprising sulfur implanted to create the recombination centers.
Claim 4
Dependent Claim
21 words
The floating-body MOSFET device of claim 1 wherein the recombination centers comprise electron traps of predetermined energy in the silicon bandgap.
Claim 5
Dependent Claim
16 words
The floating-body MOSFET device of claim 1 further comprising silicon implanted to create the recombination centers.
Claim 6
Dependent Claim
20 words
The floating-body MOSFET device of claim 1 wherein the recombination centers comprise structural or crystalline defects in the semiconductor material.
Claim 7
Dependent Claim
112 words
A floating-body n-channel MOSFET fabricated in a semiconductor material for a display panel comprising: a matrix of transistors each having n-type drain and source regions separated by a p-type channel region, the source region and the channel region forming a p-n junction such that there is a high concentration of recombination centers located in the vicinity of the p-n junction relative to a concentration of recombination centers at a second junction between the drain region and the channel region which facilitate the recombination of electrons and holes to prevent the build-up of charge in the channel region; and an optically transmissive substrate secured to the matrix of transistors with an adhesive layer.
Claim 8
Dependent Claim
112 words
A floating-body n-channel MOSFET fabricated in a semiconductor material for a display panel comprising: a matrix of transistors each having n-type drain and source regions separated by a p-type channel region, the source region and the channel region forming a p-n junction such that there is a high concentration of recombination centers located in the vicinity of the p-n junction relative to a concentration of recombination centers at a second junction between the drain region and the channel region which facilitate the recombination of electrons and holes to prevent the build-up of charge in the channel region; and an optically transmissive substrate secured to the matrix of transistors with an adhesive layer.
Claim 9
Dependent Claim
20 words
The floating-body n-channel MOSFET of claim 6 wherein the matrix of transistors comprises an active matrix for a display panel.
Claim 10
Dependent Claim
19 words
The floating-body n-channel MOSFET of claim 6 wherein the matrix of transistors is positioned over a silicon dioxide layer.
Claim 11
Dependent Claim
14 words
The floating-body n-channel MOSFET of claim 6 wherein the optically transmissive substrate comprises glass.
Claim 12
Dependent Claim
13 words
The floating-body n-channel MOSFET of claim 9 wherein the adhesive comprises an epoxy.
Claim 13
Dependent Claim
17 words
The floating-body n-channel MOSFET of claim 6 further comprising a light shield over the array of transistors.
Claim 14
Dependent Claim
19 words
The floating-body n-channel MOSFET of claim 11 wherein the light shield comprises a metal layer over the channel region.
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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) | 1999-11-26 | 2000-05-27 | 2000-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-11-26 | 2004-05-27 | 2004-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-11-26 | 2008-05-27 | 2008-11-26 | $7700.00 | Window Closed / Lapsed |