US5278787A
Expired / Lapsed
US
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Semiconductor device and method of manufacturing the same
Assignee: Intellectual Ventures I LLC
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Filing: 1992-12-11
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Granted: 1994-01-11
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Expires: 2012-12-11
Abstract
Abstract An improved structure of and a method of manufacturing a semiconductor device which comprises a semiconductor substrate of a first conductivity type, a gate region formed on one surface of the substrate and including a first gate insulating film, a first gate electrode, a second gate insulating film and a second gate electrode laminated in that order, source and drain diffusion layers formed on the one surface of the substrate with the gate region disposed between the source and drain diffusion layers, the source and drain diffusion layers having a second conductivity type different from the first conductivity type, and a diffusion layer of the first conductivity type formed in a selected region of the substrate including at least a part of an intermediate region disposed between the source and drain diffusion layers, the diffusion layer of the first conductivity type having an inclined impurity concentration higher than that of the substrate such that the concentration gradually decreases in the direction from the drain diffusion layer toward the source diffusion layer.
Inventors
- 👤 Shoichi Iwasa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:22
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0411; H10D30/60; H10D30/68; H10D30/681; H10D30/684; H10D30/685; H10B; H10B69/00
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
160 words
A semiconductor device comprising: a semiconductor substrate of a first conductivity type; a gate region formed on one surface of said substrate and including a first gate insulating film, a first gate electrode, a second gate insulating film and a second gate electrode laminated in that order; spaced source and drain diffusion layers formed on said one surface of said substrate with said gate region disposed between them, each of said source and drain diffusion layers having a second conductivity type different from the first conductivity type; and a diffusion layer also of the first conductivity type formed in a selected region of the substrate including at least a part of said one surface of said substrate under said first gate region, said diffusion layer of the first conductivity type having an inclined impurity concentration higher than that of said substrate said inclined impurity concentration gradually decreasing in a direction from said drain diffusion layer toward said source diffusion layer.
Claim 2
Dependent Claim
160 words
A semiconductor device comprising: a semiconductor substrate of a first conductivity type; a gate region formed on one surface of said substrate and including a first gate insulating film, a first gate electrode, a second gate insulating film and a second gate electrode laminated in that order; spaced source and drain diffusion layers formed on said one surface of said substrate with said gate region disposed between them, each of said source and drain diffusion layers having a second conductivity type different from the first conductivity type; and a diffusion layer also of the first conductivity type formed in a selected region of the substrate including at least a part of said one surface of said substrate under said first gate region, said diffusion layer of the first conductivity type having an inclined impurity concentration higher than that of said substrate said inclined impurity concentration gradually decreasing in a direction from said drain diffusion layer toward said source diffusion layer.
Claim 3
Dependent Claim
15 words
A semiconductor device according to claim 1, wherein said first conductivity type is a P-type.
Claim 4
Dependent Claim
27 words
A semiconductor device according to claim 1, further comprising a second diffusion layer of the second conductivity type formed in said substrate under said source diffusion layer.
Claim 5
Dependent Claim
25 words
A semiconductor device according to claim 1, wherein said diffusion layer of the first conductivity type includes boron as impurities for defining its conductivity type.
Claim 6
Dependent Claim
50 words
A semiconductor device according to claim 4, wherein the impurity concentration at an area of said diffusion layer of the first conductivity type in a vicinity of said drain region is more than ten times of the impurity concentration at another area thereof in a vicinity of said source region.
Claim 7
Independent Claim
197 words
A method of manufacturing a semiconductor device having a source region, a drain region, and a gate region disposed between said source and drain regions, comprising the steps of: forming a gate region by laminating a first gate insulating film, a first gate electrode, a second gate insulating film, and a second gate electrode in that order on one surface of a semiconductor substrate of a first conductivity type; forming a diffusion layer also of the first conductivity type but having a concentration higher than that of said semiconductor substrate, in a selected region of said semiconductor substrate including at least a part of an intermediate region disposed between first and second regions where said drain and source regions are to be formed, said diffusion layer being formed to have an inclined impurity concentration such that the impurity concentration of said diffusion layer gradually decreases in a direction from said first region toward said second region; and forming, at the first and second regions, source and drain diffusion layers of a second conductivity type different from the first conductivity type with said gate region being disposed at said intermediate region between said source and drain diffusion layers.
Claim 8
Independent Claim
197 words
A method of manufacturing a semiconductor device having a source region, a drain region, and a gate region disposed between said source and drain regions, comprising the steps of: forming a gate region by laminating a first gate insulating film, a first gate electrode, a second gate insulating film, and a second gate electrode in that order on one surface of a semiconductor substrate of a first conductivity type; forming a diffusion layer also of the first conductivity type but having a concentration higher than that of said semiconductor substrate, in a selected region of said semiconductor substrate including at least a part of an intermediate region disposed between first and second regions where said drain and source regions are to be formed, said diffusion layer being formed to have an inclined impurity concentration such that the impurity concentration of said diffusion layer gradually decreases in a direction from said first region toward said second region; and forming, at the first and second regions, source and drain diffusion layers of a second conductivity type different from the first conductivity type with said gate region being disposed at said intermediate region between said source and drain diffusion layers.
Claim 9
Dependent Claim
33 words
A method for manufacturing a semiconductor device according to claim 6, further comprising the step of forming an impurity diffusion layer of the second conductivity type under said source region of said substrate.
Claim 10
Dependent Claim
220 words
A semiconductor device comprising: a semiconductor substrate of a first conductivity type; a gate region formed on one surface of said substrate and including a first gate insulating film, a first gate electrode, a second gate insulating film and a second gate electrode laminated in that order; spaced source and drain diffusion layers formed on said one surface of said substrate with said gate region disposed between them, each of said source and drain diffusion layers having a second conductivity type different from the first conductivity type; and a diffusion layer also of the first conductivity type, formed in a selected region of the substrate including at least a part of an intermediate region disposed between said source and drain diffusion layers, said diffusion layer of the first conductivity type having an impurity concentration which is higher than that of said substrate and inclined such that the impurity concentration of said diffusion layer gradually decreases in a direction from said drain diffusion layer toward said source diffusion layer; wherein said diffusion layer of the first conductivity type includes boron as impurities for defining its conductivity type and the impurity concentration at an area of said diffusion layer near to said drain region is more than ten times of the impurity concentration at another area thereof near to said source region.
Claim 11
Dependent Claim
220 words
A semiconductor device comprising: a semiconductor substrate of a first conductivity type; a gate region formed on one surface of said substrate and including a first gate insulating film, a first gate electrode, a second gate insulating film and a second gate electrode laminated in that order; spaced source and drain diffusion layers formed on said one surface of said substrate with said gate region disposed between them, each of said source and drain diffusion layers having a second conductivity type different from the first conductivity type; and a diffusion layer also of the first conductivity type, formed in a selected region of the substrate including at least a part of an intermediate region disposed between said source and drain diffusion layers, said diffusion layer of the first conductivity type having an impurity concentration which is higher than that of said substrate and inclined such that the impurity concentration of said diffusion layer gradually decreases in a direction from said drain diffusion layer toward said source diffusion layer; wherein said diffusion layer of the first conductivity type includes boron as impurities for defining its conductivity type and the impurity concentration at an area of said diffusion layer near to said drain region is more than ten times of the impurity concentration at another area thereof near to said source region.
Claim 12
Dependent Claim
28 words
A semiconductor device according to claim 8, further comprising a second diffusion layer of the second conductivity type formed in said semiconductor substrate under said source diffusion layer.
Claim 13
Dependent Claim
214 words
A semiconductor device comprising: a semiconductor substrate of a first conductivity type; a gate region formed on one surface of said substrate and including a first gate insulating film, a first gate electrode, a second gate insulating film and a second gate electrode laminated in that order; spaced source and drain diffusion layers formed on said one surface of said substrate with said gate region disposed between them, each of said source and drain diffusion layers having a second conductivity type different from the first conductivity type; and a diffusion layer also of the first conductivity type formed in a selected region of the substrate including at least a part of an intermediate region disposed between said source and drain diffusion layers at which said gate region is formed, said diffusion layer of the first conductivity type having an inclined impurity concentration higher than that of said substrate such that the impurity concentration of said diffusion layer gradually decreases in a direction from said drain diffusion layer toward said source diffusion layer; wherein said first conductivity type is a P-type and the impurity concentration at an area of said diffusion layer near to said drain region is more than ten times of the impurity concentration at another are thereof near to said source region.
Claim 14
Dependent Claim
214 words
A semiconductor device comprising: a semiconductor substrate of a first conductivity type; a gate region formed on one surface of said substrate and including a first gate insulating film, a first gate electrode, a second gate insulating film and a second gate electrode laminated in that order; spaced source and drain diffusion layers formed on said one surface of said substrate with said gate region disposed between them, each of said source and drain diffusion layers having a second conductivity type different from the first conductivity type; and a diffusion layer also of the first conductivity type formed in a selected region of the substrate including at least a part of an intermediate region disposed between said source and drain diffusion layers at which said gate region is formed, said diffusion layer of the first conductivity type having an inclined impurity concentration higher than that of said substrate such that the impurity concentration of said diffusion layer gradually decreases in a direction from said drain diffusion layer toward said source diffusion layer; wherein said first conductivity type is a P-type and the impurity concentration at an area of said diffusion layer near to said drain region is more than ten times of the impurity concentration at another are thereof near to said source region.
Claim 15
Dependent Claim
28 words
A semiconductor device according to claim 10, further comprising a second diffusion layer of the second conductivity type formed in said semiconductor substrate under said source diffusion layer.
Claim 16
Dependent Claim
214 words
A semiconductor device comprising: a semiconductor substrate of a first conductivity type; a gate region formed on one surface of said substrate and including a first gate insulating film, a first gate electrode, a second gate insulating film and a second gate electrode laminated in that order; spaced apart source and drain diffusion layers formed on said one surface of said substrate with said gate region being disposed between them, each of said source and drain diffusion layers having a second conductivity type different from the first conductivity type; and a diffusion layer also of the first conductivity type formed in a selected region of the substrate including at least a part of an intermediate region disposed between said source and drain diffusion layers and at which said gate region is formed, said diffusion layer of the first conductivity type having an inclined impurity concentration higher than that of said substrate such that the impurity concentration of said diffusion layer gradually decreases in a direction from said drain diffusion layer toward said source diffusion layer; wherein the impurity concentration at an area of said diffusion layer of the first conductivity type near to said drain region is more than ten times of the impurity concentration at another area thereof near to said source region.
Claim 17
Dependent Claim
214 words
A semiconductor device comprising: a semiconductor substrate of a first conductivity type; a gate region formed on one surface of said substrate and including a first gate insulating film, a first gate electrode, a second gate insulating film and a second gate electrode laminated in that order; spaced apart source and drain diffusion layers formed on said one surface of said substrate with said gate region being disposed between them, each of said source and drain diffusion layers having a second conductivity type different from the first conductivity type; and a diffusion layer also of the first conductivity type formed in a selected region of the substrate including at least a part of an intermediate region disposed between said source and drain diffusion layers and at which said gate region is formed, said diffusion layer of the first conductivity type having an inclined impurity concentration higher than that of said substrate such that the impurity concentration of said diffusion layer gradually decreases in a direction from said drain diffusion layer toward said source diffusion layer; wherein the impurity concentration at an area of said diffusion layer of the first conductivity type near to said drain region is more than ten times of the impurity concentration at another area thereof near to said source region.
Claim 18
Dependent Claim
28 words
A semiconductor device according to claim 12, further comprising a second diffusion layer of the second conductivity type formed in said semiconductor substrate under said source diffusion layer.
References Cited (Backward Citations)
JPS53142304A
Cited
US4868619A
Cited
US4939558A
Cited
US4979005A
Cited
US4949140A
Cited
JPS63197609A
Cited
JPS63243644A
Cited
JPH02170544A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-01-10 | 1997-07-12 | 1998-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-10 | 2001-07-12 | 2002-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-10 | 2005-07-12 | 2006-01-11 | $7700.00 | Window Closed / Lapsed |