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US4432072A Expired / Lapsed US ⏱️ 0.0 years remaining

Non-volatile dynamic RAM cell

Assignee: International Business Machines Corp
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Filing: 1981-12-31
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Granted: 1984-02-14
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Expires: 2001-12-31
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Abstract

Abstract This invention provides improved non-volatile semiconductor memories which include a one device dynamic volatile memory circuit having a switching device, a storage capacitor and a non-volatile floating gate device disposed between the storage node and the switching device. The non-volatile floating gate device has a floating gate, a floating gate FET, a control gate and a voltage divider having first and second serially-connected capacitors, with the floating gate being disposed at the common point between the first and second capacitors. One of the capacitors includes a dual charge or electron injector structure and the capacitance of this capacitor has a value substantially less than that of the other capacitor.

Inventors

  • 👤 Hu H. Chao
  • 👤 Donelli J. DiMaria

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 11:36
CPC Classifications
G; G11; G11C; G11C14/00

Claims Analysis

Total Claims: 36
Claim 1
Independent Claim 109 words
A memory cell comprising: a storage capacitor having a storage node and a plate, means for applying a constant voltage to said plate, a control electrode, a voltage divider circuit having serially-connected first and second capacitors and a floating gate connected to a common point between said first and second capacitors, said voltage divider circuit being disposed between said control electrode and said storage node, a bit line, a switching device disposed between said storage node and said bit line, and a floating gate field effect transistor disposed between said storage node and said switching device and said floating gate field effect transistor being controlled by said floating gate.
Claim 2
Dependent Claim 109 words
A memory cell comprising: a storage capacitor having a storage node and a plate, means for applying a constant voltage to said plate, a control electrode, a voltage divider circuit having serially-connected first and second capacitors and a floating gate connected to a common point between said first and second capacitors, said voltage divider circuit being disposed between said control electrode and said storage node, a bit line, a switching device disposed between said storage node and said bit line, and a floating gate field effect transistor disposed between said storage node and said switching device and said floating gate field effect transistor being controlled by said floating gate.
Claim 3
Dependent Claim 19 words
A memory cell as set forth in claim 1 wherein said first capacitor includes a first enhanced conduction insulator.
Claim 4
Dependent Claim 32 words
A memory cell as set forth in claim 2 wherein said first capacitor further includes a second enhanced conduction insulator and a given insulating layer disposed between said first and second insulators.
Claim 5
Dependent Claim 16 words
A memory cell as set forth in claim 3 wherein said switching device is a transistor.
Claim 6
Dependent Claim 17 words
A memory cell as set forth in claim 4 wherein said transistor is a field effect transistor.
Claim 7
Dependent Claim 35 words
A memory cell as set forth in claim 5 wherein said first capacitor is disposed between said floating gate and said control electrode and has a capacitance value substantially less than that of second capacitor.
Claim 8
Dependent Claim 20 words
A memory cell as set forth in claim 6 further including means for applying a voltage to said control electrode.
Claim 9
Dependent Claim 53 words
A memory cell as set forth in claim 7 wherein said means for applying a voltage to said control electrode applies a first voltage having a given magnitude during one period of time and a second voltage having a magnitude substantially lower than that of said given magnitude during another period of time.
Claim 10
Dependent Claim 35 words
A memory cell as set forth in claim 8 wherein said given insulating layer includes a silicon dioxide layer and each of said first and second enhanced conduction insulators includes a silicon-rich silicon dioxide layer.
Claim 11
Dependent Claim 172 words
A non-volatile dynamic random access memory cell comprising: a semiconductor substrate, a storage capacitor having a plate and a storage node disposed in said substrate, a control electrode, means for applying a voltage to said control electrode, said voltage having a first magnitude during one period of time and a second magnitude substantially smaller than said first magnitude during another period of time, a voltage divider circuit having serially-connected first and second capacitors and a floating gate connected to a common point between said first and second capacitors, said voltage divider being disposed between said control electrode and said storage node, wherein said first capacitor is disposed between said floating gate and said control electrode and has a capacitive value substantially less than that of said second capacitor, a bit line disposed in said substrate, a field effect transistor disposed between said storage node and said bit line, and a floating gate FET disposed between said storage node and said field effect transistor, said floating gate FET controlled by said floating gate.
Claim 12
Dependent Claim 172 words
A non-volatile dynamic random access memory cell comprising: a semiconductor substrate, a storage capacitor having a plate and a storage node disposed in said substrate, a control electrode, means for applying a voltage to said control electrode, said voltage having a first magnitude during one period of time and a second magnitude substantially smaller than said first magnitude during another period of time, a voltage divider circuit having serially-connected first and second capacitors and a floating gate connected to a common point between said first and second capacitors, said voltage divider being disposed between said control electrode and said storage node, wherein said first capacitor is disposed between said floating gate and said control electrode and has a capacitive value substantially less than that of said second capacitor, a bit line disposed in said substrate, a field effect transistor disposed between said storage node and said bit line, and a floating gate FET disposed between said storage node and said field effect transistor, said floating gate FET controlled by said floating gate.
Claim 13
Dependent Claim 23 words
A non-volatile dynamic random access memory cell as set forth in claim 10 wherein said first capacitor includes a first enhanced conduction insulator.
Claim 14
Dependent Claim 36 words
A non-volatile dynamic random access memory cell as set forth in claim 11 wherein said first capacitor further includes a second enhanced conduction insulator and a given insulating layer disposed between said first and second insulators.
Claim 15
Dependent Claim 42 words
A non-volatile dynamic random access memory cell as set forth in claim 12 wherein said first capacitor includes a layer of silicon dioxide and first and second layers of silicon-rich silicon dioxide disposed on opposite sides of said layer of silicon dioxide.
Claim 16
Dependent Claim 149 words
A non-volatile dynamic random access memory cell comprising: a semiconductor substrate, a storage capacitor having a plate and a storage node disposed in said substrate, a control electrode, a switching node, a switching device, means for applying a voltage to said control electrode, said voltage having a first magnitude during one period of time and a second magnitude substantially smaller than said first magnitude during another period of time, a voltage divider circuit having serially-connected first and second capacitors and a floating gate connected to a common point between said first and second capacitors, said voltage divider being disposed between said control electrode and said switching node, a bit/sense line disposed in said substrate, a switching device between said storage node and said bit/sense line, and a floating gate FET disposed between said storage node and said switching device said floating gate FET being controlled by said floating gate.
Claim 17
Dependent Claim 149 words
A non-volatile dynamic random access memory cell comprising: a semiconductor substrate, a storage capacitor having a plate and a storage node disposed in said substrate, a control electrode, a switching node, a switching device, means for applying a voltage to said control electrode, said voltage having a first magnitude during one period of time and a second magnitude substantially smaller than said first magnitude during another period of time, a voltage divider circuit having serially-connected first and second capacitors and a floating gate connected to a common point between said first and second capacitors, said voltage divider being disposed between said control electrode and said switching node, a bit/sense line disposed in said substrate, a switching device between said storage node and said bit/sense line, and a floating gate FET disposed between said storage node and said switching device said floating gate FET being controlled by said floating gate.
Claim 18
Dependent Claim 40 words
A non-volatile dynamic random access memory cell as set forth in claim 14 wherein said first capacitor is disposed between said floating gate and said control electrode and has a capacitance value substantially less than that of said second capacitor.
Claim 19
Dependent Claim 23 words
A non-volatile dynamic random access memory cell as set forth in claim 15 wherein said first capacitor includes a first enhanced conduction insulator.
Claim 20
Dependent Claim 32 words
A memory cell as set forth in claim 16 wherein said first capacitor further includes a second enhanced conduction insulator and a given insulating layer disposed between said first and second insulators.
Claim 21
Dependent Claim 42 words
A non-volatile dynamic random access memory cell as set forth in claim 17 wherein said first capacitor includes a layer of silicon dioxide and first and second layer of silicon-rich silicon dioxide disposed on opposite sides of said layer of silicon dioxide.
Claim 22
Dependent Claim 112 words
A memory cell comprising: a storage capacitor having a storage node and a plate, means for applying a constant voltage to said plate, a control electrode, a switching node, a voltage divider circuit having serially-connected first and second capacitors and a floating gate connected to a common point between said first and second capacitors, said voltage divider circuit being disposed between said control electrode and said switching node, a bit line, a switching device disposed between said switching node and said bit line, and a floating gate field effect transistor disposed between said storage node and said switching node and said floating gate field effect transistor being controlled by said floating gate.
Claim 23
Dependent Claim 112 words
A memory cell comprising: a storage capacitor having a storage node and a plate, means for applying a constant voltage to said plate, a control electrode, a switching node, a voltage divider circuit having serially-connected first and second capacitors and a floating gate connected to a common point between said first and second capacitors, said voltage divider circuit being disposed between said control electrode and said switching node, a bit line, a switching device disposed between said switching node and said bit line, and a floating gate field effect transistor disposed between said storage node and said switching node and said floating gate field effect transistor being controlled by said floating gate.
Claim 24
Dependent Claim 19 words
A memory cell as set forth in claim 19 wherein said second capacitor includes a first enhanced conduction insulator.
Claim 25
Dependent Claim 32 words
A memory cell as set forth in claim 20 wherein said second capacitor further includes a second enhanced conduction insulator and a given insulating layer disposed between said first and second insulators.
Claim 26
Dependent Claim 16 words
A memory cell as set forth in claim 21 wherein said switching device is a transistor.
Claim 27
Dependent Claim 17 words
A memory cell as set forth in claim 22 wherein said transistor is a field effect transistor.
Claim 28
Dependent Claim 36 words
A memory cell as set forth in claim 23 wherein said second capacitor is disposed between said floating gate and said switching node and has a capacitance value substantially less than that of said first capacitor.
Claim 29
Dependent Claim 20 words
A memory cell as set forth in claim 24 further including means for applying a voltage to said control electrode.
Claim 30
Dependent Claim 53 words
A memory cell as set forth in claim 25 wherein said means for applying a voltage to said control electrode, applies a first voltage having a given magnitude during one period of time and a second voltage having a magnitude substantially lower than that of the given magnitude during another period of time.
Claim 31
Dependent Claim 35 words
A memory cell as set forth in claim 26 wherein said given insulating layer includes a silicon dioxide layer and each of said first and second enhanced conduction insulators includes a silicon-rich silicon dioxide layer.
Claim 32
Dependent Claim 174 words
A non-volatile dynamic random access memory cell comprising: a semiconductor substrate, a storage capacitor having a plate and a storage node disposed in said substrate, a control electrode, a switching node, means for applying a voltage to said control electrode, said voltage having a first magnitude during one period of time and a second magnitude substantially smaller than said first magnitude during another period of time, a voltage divider circuit having serially-connected first and second capacitors and a floating gate connected to a common point between said first and second capacitors, said voltage divider being disposed between said control electrode and said switching node, wherein said second capacitor is disposed between said floating gate and said switching node and has a capacitive value substantially less than that of said first capacitor, a bit line disposed in said substrate, a field effect transistor disposed between said switching node and said bit line, and a floating gate FET disposed between said storage node and said switching node, said floating gate FET controlled by said floating gate.
Claim 33
Dependent Claim 174 words
A non-volatile dynamic random access memory cell comprising: a semiconductor substrate, a storage capacitor having a plate and a storage node disposed in said substrate, a control electrode, a switching node, means for applying a voltage to said control electrode, said voltage having a first magnitude during one period of time and a second magnitude substantially smaller than said first magnitude during another period of time, a voltage divider circuit having serially-connected first and second capacitors and a floating gate connected to a common point between said first and second capacitors, said voltage divider being disposed between said control electrode and said switching node, wherein said second capacitor is disposed between said floating gate and said switching node and has a capacitive value substantially less than that of said first capacitor, a bit line disposed in said substrate, a field effect transistor disposed between said switching node and said bit line, and a floating gate FET disposed between said storage node and said switching node, said floating gate FET controlled by said floating gate.
Claim 34
Dependent Claim 23 words
A non-volatile dynamic random access memory cell as set forth in claim 28 wherein said second capacitor includes a first enhanced conduction insulator.
Claim 35
Dependent Claim 36 words
A non-volatile dynamic random access memory cell as set forth in claim 29 wherein said second capacitor further includes a second enhanced conduction insulator and a given insulating layer disposed between said first and second insulators.
Claim 36
Dependent Claim 42 words
A non-volatile dynamic random access memory cell as set forth in claim 30 wherein said second capacitor includes a layer of silicon dioxide and first and second layers of silicon-rich silicon dioxide disposed on opposite sides of said layer of silicon dioxide.

References Cited (Backward Citations)

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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) 1987-02-13 1987-08-15 1988-02-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-02-13 1991-08-15 1992-02-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-02-13 1995-08-15 1996-02-14 $7700.00 Window Closed / Lapsed

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