EP0703628A2
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EP
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Enhanced mobility MOSFET device and method
Assignee: Motorola Solutions Inc
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Filing: 1995-09-11
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Granted: —
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Expires: 2015-09-11
Abstract
Abstract An enhanced mobility MOSFET device (10) comprises a channel layer (12) formed on a monocrystalline silicon layer (11). The channel layer (12) comprises an alloy of silicon and a second material with the second material substitutionally present in silicon lattice sites at an atomic percentage that places the channel layer (12) under a tensile stress.
Inventors
- 👤 Jon J. Canelaria
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 05:55
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/60; H10D12/00; H10D12/01; H10D12/031; H10D30/0223; H10D30/751; H10D62/00; H10D62/80; H10D62/83; H10D62/832; H10D62/8325; H10D84/00; H10D84/01; H10D84/0123; H10D84/0126; H10D84/0128; H10D84/013; H10D84/0135; H10D84/0142; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6326; H10P14/6349; Y; Y10; Y10S; Y10S438/00; Y10S438/931
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
156 words
An enhanced mobility MOSFET device comprising: a monocrystalline silicon layer (11) of a first conductivity type; a carrier transport region (12) formed on the monocrystalline silicon layer (11), wherein the carrier transport region (12) comprises an alloy of silicon and a second semiconductor material, and wherein the second semiconductor material is substitutionally present in carrier transport region (12) lattice sites at an atomic percentage such that the carrier transport region is under tensile stress; a source region (14) of a second conductivity type extending into the carrier transport region (12); a drain region (16) of the second conductivity type extending into the carrier transport region (12), wherein a portion of the carrier transport region (12) is between the source region (14) and the drain region (16); and a control electrode (18) electrically insulated from the carrier transport region (12), wherein the control electrode (18) is disposed between the source region (14) and the drain region (16).
Claim 2
Dependent Claim
52 words
The device of claim 1 further comprising: an epitaxial layer (13) of the first semiconductor material disposed between the carrier transport region (12) and the control electrode (18), wherein the source region (14) and the drain region (16) extend through the epitaxial layer (13) into at least the carrier transport region (12).
Claim 3
Dependent Claim
18 words
The device of claim 1 wherein the carrier transport region (12) comprises a Si 1-X C X alloy.
Claim 4
Dependent Claim
14 words
The device of claim 3 wherein X is less than or equal to 0.02.
Claim 5
Dependent Claim
168 words
A MOSFET structure having a buried carbon-doped silicon channel region comprising: a channel layer (12) comprises a Si 1-X C X alloy formed on a monocrystalline silicon layer (11) of a first conductivity type, wherein carbon is present in the channel layer (12) in substitutional lattice sites so that the channel layer (12) is under tensile stress; an epitaxial silicon layer (13) formed on the channel layer; a source region (14) of a second conductivity type extending through the epitaxial silicon layer (13) and at least into the channel layer (12); a drain region (16) of the second conductivity type extending through the epitaxial silicon layer (13) and at least into the channel layer (12), wherein part of the channel layer (12) separates the source region (14) from the drain region (16); a gate dielectric layer (17) formed on the epitaxial silicon layer (13) at least between the source region (14) and the drain region (16); and a gate electrode (18) formed on the gate dielectric layer (17).
Claim 6
Dependent Claim
58 words
The structure of claim 5 wherein X is less than or equal to 0.02, and wherein the monocrystalline silicon layer (11) has a thickness on an order of 1000 angstroms, the channel layer (12) has a thickness on an order of 100 angstroms, and the epitaxial silicon layer (13) has a thickness on an order of 50 angstroms.
Claim 7
Dependent Claim
18 words
The structure of claim 5 further comprising an insulating region (51) disposed below the monocrystalline silicon layer (11).
Claim 8
Dependent Claim
76 words
The structure of claim 5 wherein the monocrystalline silicon layer (11) includes a modulation layer (41) disposed within the monocrystalline silicon layer (11), wherein a portion of the monocrystalline silicon layer (11) separates the modulation layer (41) from the channel layer (21), and wherein the modulation layer (41) is of the second conductivity type, and wherein the modulation layer (41) has a dopant concentration that is higher than dopant concentration in the monocrystalline silicon layer (11).
Claim 9
Independent Claim
200 words
A method for making an enhanced mobility MOSFET device comprising the steps of: forming a carrier transport region (12) on a first conductivity type monocrystalline silicon layer (11), wherein the carrier transport region (12) comprises an alloy of the silicon and a second semiconductor material, and wherein the second semiconductor material is substitutionally present in carrier transport region (12) lattice sites at an atomic percentage that places the carrier transport region (12) under tensile stress compared to the first conductivity type monocrystalline silicon layer (11); forming an epitaxial semiconductor layer (13) over the carrier transport region (12); forming a gate dielectric layer (17) on the epitaxial semiconductor layer (13) above a portion of the carrier transport layer (12); forming a control electrode (18) on the gate dielectric layer (17); forming a source region (14) of a second conductivity type extending through the epitaxial semiconductor layer (13) at least into the carrier transport region (12); and forming a drain region (16) of the second conductivity type extending through the epitaxial semiconductor layer (13) at least into the carrier transport region (12), wherein the portion of the carrier transport region (12) is between the source region (14) and the drain region (16).
Claim 10
Dependent Claim
38 words
The method of claim 9 wherein the step of forming the carrier transport region (12) includes forming a carrier transport region (12) comprising a Si 1-X C X alloy, wherein X is less than or equal to 0.02.
References Cited (Backward Citations)
US5241197A
Cited
US5360986A
Cited
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