US5977560A
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Thin film transistor constructions with polycrystalline silicon-germanium alloy doped with carbon in the channel region
Assignee: Micron Technology Inc
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Filing: 1997-05-09
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Granted: 1999-11-02
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Expires: 2017-05-09
Abstract
Abstract A thin film transistor includes, a) a thin film source region; b) a thin film drain region; c) a polycrystalline thin film channel region intermediate the thin film source region and the thin film drain region; d) a transistor gate and gate dielectric operatively positioned adjacent the thin film channel region; and e) the thin film channel region comprising at least an inner layer, an outer layer and a middle layer sandwiched between the inner layer and the outer layer, the inner layer and the outer layer comprising polycrystalline silicon and having respective energy bandgaps, the middle sandwich layer comprising a polycrystalline material and having a lower energy bandgap than either of the inner and outer layers. Alternately, the channel region is homogeneous, comprising germanium or an alloy of polycrystalline silicon and germanium. A method of increasing the size of individual crystal grains in a polycrystalline silicon alloy includes, a) providing germanium atoms within a layer of polycrystalline silicon to form a polycrystalline silicon-germanium alloy; and b) heating the polycrystalline silicon-germanium alloy to an effective temperature for an effective period of time to cause individual polycrystalline silicon grains within the alloy to increase their size from prior to the heating step.
Inventors
- 👤 Sanjay Banerjee
- 👤 Shubneesh Batra
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:08
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/38; H10P14/3802; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/60; H10D30/67; H10D30/6704; H10D30/6713; H10D30/6715; H10D30/6717; H10D30/674; H10D30/6741; H10D30/6748; H10P14/32; H10P14/3202; H10P14/3238; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
56 words
A thin film transistor comprising: a thin film channel region intermediate a thin film source region and a thin film drain region; and the thin film channel region comprising a first layer consisting essentially of germanium and a second layer proximate the first layer, wherein the second layer comprises a polycrystalline silicon-germanium alloy doped with carbon.
Claim 2
Dependent Claim
56 words
A thin film transistor comprising: a thin film channel region intermediate a thin film source region and a thin film drain region; and the thin film channel region comprising a first layer consisting essentially of germanium and a second layer proximate the first layer, wherein the second layer comprises a polycrystalline silicon-germanium alloy doped with carbon.
Claim 3
Dependent Claim
28 words
A transistor channel region comprising: at least two distinct layers, at least one of said at least two distinct layers comprising a polycrystalline silicon-germanium alloy doped with carbon.
Claim 4
Dependent Claim
28 words
A transistor channel region comprising: at least two distinct layers, at least one of said at least two distinct layers comprising a polycrystalline silicon-germanium alloy doped with carbon.
Claim 5
Dependent Claim
94 words
A thin film transistor comprising: a thin film source region; a thin film drain region; a thin film channel region intermediate the thin film source region and the thin film drain region; the thin film channel region comprising at least an inner layer, an outer layer and a middle layer sandwiched between the inner layer and the outer layer, the middle sandwich layer consisting essentially of germanium; and wherein the inner and outer layers are composed of the same material, wherein the inner and outer layers comprise a polycrystalline silicon-germanium alloy doped with carbon.
Claim 6
Dependent Claim
94 words
A thin film transistor comprising: a thin film source region; a thin film drain region; a thin film channel region intermediate the thin film source region and the thin film drain region; the thin film channel region comprising at least an inner layer, an outer layer and a middle layer sandwiched between the inner layer and the outer layer, the middle sandwich layer consisting essentially of germanium; and wherein the inner and outer layers are composed of the same material, wherein the inner and outer layers comprise a polycrystalline silicon-germanium alloy doped with carbon.
Claim 7
Dependent Claim
120 words
A thin film transistor comprising: a silicon semiconductor substrate; a thin film source region over the substrate; a thin film drain region over the substrate; a thin film channel region intermediate the thin film source region and the thin film drain region; the thin film channel region comprising at least an inner layer, an outer layer and a middle layer sandwiched between the inner layer and the outer layer, the middle sandwich layer consisting essentially of germanium, at least one of the inner and outer layers comprising a polycrystalline silicon-germanium alloy doped with carbon; and a drain-offset region intermediate the drain region and channel region, the drain-offset region comprising a same material extension of the sandwich thin film channel region.
Claim 8
Dependent Claim
120 words
A thin film transistor comprising: a silicon semiconductor substrate; a thin film source region over the substrate; a thin film drain region over the substrate; a thin film channel region intermediate the thin film source region and the thin film drain region; the thin film channel region comprising at least an inner layer, an outer layer and a middle layer sandwiched between the inner layer and the outer layer, the middle sandwich layer consisting essentially of germanium, at least one of the inner and outer layers comprising a polycrystalline silicon-germanium alloy doped with carbon; and a drain-offset region intermediate the drain region and channel region, the drain-offset region comprising a same material extension of the sandwich thin film channel region.
Claim 9
Dependent Claim
24 words
The thin film transistor of claim 4 wherein both the inner layer and the outer layer comprise a polycrystalline silicon-germanium alloy doped with carbon.
Claim 10
Dependent Claim
130 words
A bottom-gated thin film transistor comprising: a transistor gate; a dielectric layer over the transistor gate and extending laterally beyond the transistor gate; a thin film channel region over a portion of the dielectric layer that is over the transistor gate, the thin film channel region comprising a first layer consisting essentially of germanium and a second layer proximate the first layer, wherein the second layer comprises a polycrystalline silicon-germanium alloy doped with carbon; a thin film source region over a portion of the dielectric layer that extends laterally beyond the transistor gate; and a thin film drain region over another portion of the dielectric layer that extends laterally beyond the transistor gate, the thin film channel region separating the thin film source region from the thin film drain region.
Claim 11
Dependent Claim
130 words
A bottom-gated thin film transistor comprising: a transistor gate; a dielectric layer over the transistor gate and extending laterally beyond the transistor gate; a thin film channel region over a portion of the dielectric layer that is over the transistor gate, the thin film channel region comprising a first layer consisting essentially of germanium and a second layer proximate the first layer, wherein the second layer comprises a polycrystalline silicon-germanium alloy doped with carbon; a thin film source region over a portion of the dielectric layer that extends laterally beyond the transistor gate; and a thin film drain region over another portion of the dielectric layer that extends laterally beyond the transistor gate, the thin film channel region separating the thin film source region from the thin film drain region.
Claim 12
Dependent Claim
175 words
A bottom-gated thin film transistor comprising: a transistor gate; a dielectric layer over the transistor gate and extending laterally beyond the transistor gate; a thin film source region over a portion of the dielectric layer that extends laterally beyond the transistor gate; a thin film drain region over another portion of the dielectric layer that extends laterally beyond the transistor gate; a thin film channel region intermediate the thin film source region and the thin film drain region, the thin film channel region being over a portion of the dielectric layer that is over the transistor gate, the thin film channel region comprising at least an inner layer, an outer layer and a middle layer sandwiched between the inner layer and the outer layer, the middle sandwich layer consisting essentially of germanium, at least one of the inner and outer layers comprising a polycrystalline silicon-germanium alloy doped with carbon; and a drain-offset region intermediate the drain region and channel region, the drain-offset region comprising a same material extension of the sandwich thin film channel region.
Claim 13
Dependent Claim
175 words
A bottom-gated thin film transistor comprising: a transistor gate; a dielectric layer over the transistor gate and extending laterally beyond the transistor gate; a thin film source region over a portion of the dielectric layer that extends laterally beyond the transistor gate; a thin film drain region over another portion of the dielectric layer that extends laterally beyond the transistor gate; a thin film channel region intermediate the thin film source region and the thin film drain region, the thin film channel region being over a portion of the dielectric layer that is over the transistor gate, the thin film channel region comprising at least an inner layer, an outer layer and a middle layer sandwiched between the inner layer and the outer layer, the middle sandwich layer consisting essentially of germanium, at least one of the inner and outer layers comprising a polycrystalline silicon-germanium alloy doped with carbon; and a drain-offset region intermediate the drain region and channel region, the drain-offset region comprising a same material extension of the sandwich thin film channel region.
Claim 14
Dependent Claim
25 words
The bottom-gated thin film transistor of claim 7 wherein both the inner layer and the outer layer comprise a polycrystalline silicon-germanium alloy doped with carbon.
References Cited (Backward Citations)
US4885614A
Cited
JPH01120069A
Cited
US4891329A
Cited
US5241197A
Cited
US5324122A
Cited
JPH04168769A
Cited
JPH04271126A
Cited
US5218213A
Cited
US5240876A
Cited
US5296386A
Cited
US5323031A
Cited
JPH04313242A
Cited
JPH04320063A
Cited
US5442205A
Cited
US5246886A
Cited
US5166084A
Cited
JPH0594929A
Cited
JPH05129635A
Cited
JPH05175538A
Cited
US5591653A
Cited
US5241193A
Cited
US5268324A
Cited
US5461250A
Cited
US5323020A
Cited
US5527724A
Cited
US5354700A
Cited
US5479033A
Cited
US5665981A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2002-11-01 | 2003-05-03 | 2003-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-11-01 | 2007-05-03 | 2007-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-11-01 | 2011-05-03 | 2011-11-02 | $7700.00 | Window Closed / Lapsed |