← Back to Patent Explorer
US5780893A Expired / Lapsed US ⏱️ 0.0 years remaining

Non-volatile semiconductor memory device including memory transistor with a composite gate structure

Assignee: Intellectual Ventures I LLC
•
Filing: 1996-12-19
•
Granted: 1998-07-14
•
Expires: 2016-12-19
📄 Original PDF 🌐 Google Patents

Abstract

Abstract A non-volatile semiconductor memory device including a memory cell having a memory transistor and a selection transistor, comprising: a composite gate structure of the memory transistor formed on a surface of a semiconductor substrate at its first region with a first insulating film interposed therebetween and including a laminate of a floating gate electrode, a second insulating film and a control gate electrode; a gate electrode of the selection transistor formed on the surface of the semiconductor substrate at its second region close to the first region with a third insulating film interposed therebetween; and an impurity diffusion layer formed in the semiconductor substrate at its region between the first and second regions and functioning as a drain of the memory transistor, common to a source of the selection transistor, the impurity diffusion layer having at least an extension region extending to a part of the semiconductor substrate disposed under the composite gate structure, the extension region having first, second and third layers wherein the first and second layers include first and second impurities at first and second different concentrations, respectively, and the third layer includes a third impurity at a third concentration higher than any one of the first and second concentrations and a method of manufacturing the non-volatile semiconductor memory device as above-mentioned.

Inventors

  • 👤 Fumitaka Sugaya

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 14:17
CPC Classifications
H; H10; H10B; H10B41/00; H10B41/30; H10B41/35; H10B69/00; H10D; H10D30/00; H10D30/60; H10D30/68; H10D30/6891; H10D64/00; H10D64/60; H10D64/66; H10D64/68; H10D64/681; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/01342

Claims Analysis

Total Claims: 41
Claim 1
Independent Claim 178 words
A non-volatile semiconductor memory device comprising: a composite gate structure formed on a surface of a semiconductor substrate with a first insulating film interposed therebetween and including a laminate of a floating gate electrode, a second insulating film and a control gate electrode; and a pair of impurity diffusion layers formed in the semiconductor substrate at its regions on both sides of the composite gate structure, at least one of said impurity diffusion layers having an extension region extending to a part of the semiconductor substrate disposed under the composite gate structure, so that said one impurity diffusion layer and said composite gate structure overlap with each other at said extension region of said one impurity diffusion layer, the extension region having first, second and third layers, wherein the first and second layers include first and second impurities at first and second different concentrations, respectively, and the third layer includes a third impurity at a third concentration higher than any of the first and second concentrations, said first, second and third impurities being of the same conductivity type.
Claim 2
Dependent Claim 178 words
A non-volatile semiconductor memory device comprising: a composite gate structure formed on a surface of a semiconductor substrate with a first insulating film interposed therebetween and including a laminate of a floating gate electrode, a second insulating film and a control gate electrode; and a pair of impurity diffusion layers formed in the semiconductor substrate at its regions on both sides of the composite gate structure, at least one of said impurity diffusion layers having an extension region extending to a part of the semiconductor substrate disposed under the composite gate structure, so that said one impurity diffusion layer and said composite gate structure overlap with each other at said extension region of said one impurity diffusion layer, the extension region having first, second and third layers, wherein the first and second layers include first and second impurities at first and second different concentrations, respectively, and the third layer includes a third impurity at a third concentration higher than any of the first and second concentrations, said first, second and third impurities being of the same conductivity type.
Claim 3
Dependent Claim 19 words
A non-volatile semiconductor memory device according to claim 1, wherein said first concentration is lower than said second concentration.
Claim 4
Dependent Claim 24 words
A non-volatile semiconductor memory device according to claim 1, wherein said first and second layers surround at least a part of said third layer.
Claim 5
Dependent Claim 22 words
A non-volatile semiconductor memory device according to claim 3, wherein said first layer surrounds at least a part of said second layer.
Claim 6
Dependent Claim 19 words
A non-volatile semiconductor memory device according to claim 4, wherein said first concentration is lower than said second concentration.
Claim 7
Dependent Claim 24 words
A non-volatile semiconductor memory device according to claim 1, wherein said first impurity has a diffusion coefficient larger than that of said second impurity.
Claim 8
Dependent Claim 23 words
A non-volatile semiconductor memory device according to claim 6, wherein said first impurity includes mainly phosphorus, and said second impurity includes mainly arsenic.
Claim 9
Dependent Claim 23 words
A non-volatile semiconductor memory device according to claim 6, wherein said first impurity includes mainly phosphorus, and said second impurity includes mainly antimony.
Claim 10
Dependent Claim 23 words
A non-volatile semiconductor memory device according to claim 6, wherein said first impurity includes mainly phosphorus, and said second impurity includes mainly bismuth.
Claim 11
Dependent Claim 47 words
A non-volatile semiconductor memory device according to claim 1, wherein said first concentration is in a range of 1×10 18 atoms/cm 3 to 1×10 19 atoms/cm 3 , and said second concentration is in a range of 5×10 20 atoms/cm 3 to 2×10 21 atoms/cm 3 .
Claim 12
Dependent Claim 38 words
A non-volatile semiconductor memory device according to claim 1, wherein said semiconductor substrate is of a first conductivity type, and said first, second and third impurities are of a second conductivity type opposite to said first conductivity type.
Claim 13
Dependent Claim 40 words
A non-volatile semiconductor memory device according to claim 1, wherein said composite gate structure and said pair of impurity diffused layers constitute a memory transistor, and one of said impurity diffused layers is a drain region of said memory transistor.
Claim 14
Dependent Claim 42 words
A non-volatile semiconductor memory device according to claim 12, wherein said memory transistor has such a structure as to write data by injecting electrons from said drain region into said floating gate electrode by FN tunnelling phenomenon through said first insulating film.
Claim 15
Dependent Claim 152 words
A semiconductor device comprising: a gate structure formed on a surface of a semiconductor substrate with an insulating film interposed therebetween; and a pair of impurity diffusion layers formed in said semiconductor substrate at its regions at both sides of said gate structure; at least one of said impurity diffusion layers having an extension region extending to a part of the semiconductor substrate disposed under said gate structure, so that said one impurity diffusion layer and said gate structure overlap each other at said extension region of said one impurity diffusion layer, said extension region having first, second and third layers, wherein said first and second layers include first and second impurities at first and second different concentrations, respectively, and said third layer includes a third impurity at a third concentration higher than any of said first and second concentrations, said first, second and third impurities being of the same conductivity type.
Claim 16
Dependent Claim 152 words
A semiconductor device comprising: a gate structure formed on a surface of a semiconductor substrate with an insulating film interposed therebetween; and a pair of impurity diffusion layers formed in said semiconductor substrate at its regions at both sides of said gate structure; at least one of said impurity diffusion layers having an extension region extending to a part of the semiconductor substrate disposed under said gate structure, so that said one impurity diffusion layer and said gate structure overlap each other at said extension region of said one impurity diffusion layer, said extension region having first, second and third layers, wherein said first and second layers include first and second impurities at first and second different concentrations, respectively, and said third layer includes a third impurity at a third concentration higher than any of said first and second concentrations, said first, second and third impurities being of the same conductivity type.
Claim 17
Dependent Claim 17 words
A semiconductor device according to claim 14, wherein said first concentration is lower than said second concentration.
Claim 18
Dependent Claim 22 words
A semiconductor device according to claim 14, wherein said first and second layers surround at least a part of said third layer.
Claim 19
Dependent Claim 20 words
A semiconductor device according to claim 16, wherein said first layer surrounds at least a part of said second layer.
Claim 20
Dependent Claim 17 words
A semiconductor device according to claim 17, wherein said first concentration is lower than said second concentration.
Claim 21
Dependent Claim 22 words
A semiconductor device according to claim 14, wherein said first impurity has a diffusion coefficient larger than that of said second impurity.
Claim 22
Dependent Claim 21 words
A semiconductor device according to claim 19, wherein said first impurity includes mainly phosphorus, and said second impurity includes mainly arsenic.
Claim 23
Dependent Claim 21 words
A semiconductor device according to claim 19, wherein said first impurity includes mainly phosphorus, and said second impurity includes mainly antimony.
Claim 24
Dependent Claim 21 words
A semiconductor device according to claim 19, wherein said first impurity includes mainly phosphorus, and said second impurity includes mainly bismuth.
Claim 25
Dependent Claim 45 words
A semiconductor device according to claim 14, wherein said first concentration is in a range of 1×10 18 atoms/cm 3 to 1×10 19 atoms/cm 3 , and said second concentration is in a range of 5×10 20 atoms/cm 3 to 2×10 21 atoms/cm 3 .
Claim 26
Dependent Claim 36 words
A semiconductor device according to claim 14, wherein said semiconductor substrate is of a first conductivity type, and said first, second and third impurities are of a second conductivity type opposite to said first conductivity type.
Claim 27
Dependent Claim 35 words
A semiconductor device according to claim 14, wherein said gate structure and said pair of impurity diffusion layers constitute a transistor, and one of said impurity diffusion layers is a drain region of said transistor.
Claim 28
Dependent Claim 232 words
A semiconductor device including a memory transistor and a selection transistor, said semiconductor device comprising: a composite gate structure of the memory transistor formed on a surface of a semiconductor substrate at its first region with a first insulating film interposed therebetween and including a laminate of a floating gate electrode, a second insulating film and a control gate electrode; a gate structure of the selection transistor formed on the surface of the semiconductor substrate at its second region close to said first region with a third insulating film interposed therebetween; an impurity diffusion layer formed in the semiconductor substrate at a region between said first and second regions and functioning as a drain of said memory transistor common to a source of said selection transistor, said impurity diffusion layer having an extension region extending to a part of said semiconductor substrate disposed under said composite gate structure, so that said impurity diffusion layer and said composite gate structure overlap with each other at said extension region of said impurity diffusion layer, said extension region having first, second and third layers, wherein said first and second layers include first and second impurities at first and second different concentrations, respectively, and said third layer includes a third impurity at a third concentration higher than any of said first and second concentrations, said first, second and third impurities being of the same conductivity type.
Claim 29
Dependent Claim 232 words
A semiconductor device including a memory transistor and a selection transistor, said semiconductor device comprising: a composite gate structure of the memory transistor formed on a surface of a semiconductor substrate at its first region with a first insulating film interposed therebetween and including a laminate of a floating gate electrode, a second insulating film and a control gate electrode; a gate structure of the selection transistor formed on the surface of the semiconductor substrate at its second region close to said first region with a third insulating film interposed therebetween; an impurity diffusion layer formed in the semiconductor substrate at a region between said first and second regions and functioning as a drain of said memory transistor common to a source of said selection transistor, said impurity diffusion layer having an extension region extending to a part of said semiconductor substrate disposed under said composite gate structure, so that said impurity diffusion layer and said composite gate structure overlap with each other at said extension region of said impurity diffusion layer, said extension region having first, second and third layers, wherein said first and second layers include first and second impurities at first and second different concentrations, respectively, and said third layer includes a third impurity at a third concentration higher than any of said first and second concentrations, said first, second and third impurities being of the same conductivity type.
Claim 30
Dependent Claim 35 words
A semiconductor device according to claim 26, wherein said semiconductor device is a non-volatile semiconductor memory device and said memory transistor and said first transistor constitute a memory cell of said non-volatile semiconductor memory device.
Claim 31
Dependent Claim 17 words
A semiconductor device according to claim 27, wherein said first concentration is lower than said second concentration.
Claim 32
Dependent Claim 22 words
A semiconductor device according to claim 27, wherein said first and second layers surround at least a part of said third layer.
Claim 33
Dependent Claim 20 words
A semiconductor device according to claim 29, wherein said first layer surrounds at least a part of said second layer.
Claim 34
Dependent Claim 17 words
A semiconductor device according to claim 30, wherein said first concentration is lower than said second concentration.
Claim 35
Dependent Claim 22 words
A semiconductor device according to claim 27, wherein said first impurity has a diffusion coefficient larger than that of said second impurity.
Claim 36
Dependent Claim 21 words
A semiconductor device according to claim 32, wherein said first impurity includes mainly phosphorus, and said second impurity includes mainly arsenic.
Claim 37
Dependent Claim 21 words
A semiconductor device according to claim 32, wherein said first impurity includes mainly phosphorus, and said second impurity includes mainly antimony.
Claim 38
Dependent Claim 21 words
A semiconductor device according to claim 32, wherein said first impurity includes mainly phosphorus, and said second impurity includes mainly bismuth.
Claim 39
Dependent Claim 45 words
A semiconductor device according to claim 27, wherein said first concentration is in a range of 1×10 18 atoms/cm 3 to 1×10 19 atoms/cm 3 , and said second concentration is in a range of 5×10 20 atoms/cm 3 to 2×10 21 atoms/cm 3 .
Claim 40
Dependent Claim 36 words
A semiconductor device according to claim 27, wherein said semiconductor substrate is of a first conductivity type, and said first, second and third impurities are of a second conductivity type opposite to said first conductivity type.
Claim 41
Dependent Claim 40 words
A semiconductor device according to claim 27, wherein said memory transistor has such a structure as to write data by injecting electrons from said drain region into said floating gate electrode through said first insulating film by FN tunnelling phenomenon.

References Cited (Backward Citations)

JPS60110167A Cited
JPS63301566A Cited
US5345104A Cited
US5502321A Cited
US5585293A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-07-13 2002-01-12 2002-07-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-07-13 2006-01-12 2006-07-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-07-13 2010-01-12 2010-07-14 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag