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US3979734A Expired / Lapsed US ⏱️ 0.0 years remaining

Multiple element charge storage memory cell

Assignee: International Business Machines Corp
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Filing: 1975-06-16
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Granted: 1976-09-07
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Expires: 1995-06-16
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Abstract

Abstract An integrated circuit memory system includes capacitive storage memory cells capable of storing n bits of information on n capacitors associated with multiple emitters of a bilaterally conductive bipolar transistor. Each capacitor is coupled to a separate bit/sense line. Access of a storage cell is achieved by forward biasing the common base/collector junction of the bipolar transistor. Writing is achieved by driving the bit/sense lines to charge or discharge the storage capacitors during an access cycle. In reading, or sensing, the charged state of each storage capacitor is determined by sensing potential changes on the bit/sense lines during access. Fabrication of memory arrays is possible by any one of several different techniques, all of which are compatible with high speed bipolar logic circuits.

Inventors

  • 👤 Wilbur David Pricer
  • 👤 James Earl Selleck

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 04:56
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/21; G11C11/24; G11C11/34; G11C11/40; G11C11/401; G11C11/403; G11C11/56; G11C11/565; H; H10; H10B; H10B12/00; H10B12/10; H10D; H10D84/00; H10D84/60; H10D84/611; H10D84/613; H10D84/615; H10D86/00

Claims Analysis

Total Claims: 29
Claim 1
Independent Claim 80 words
An information storage system including a plurality of addressable memory cells, each of said memory cells comprising: a plurality of two terminal capacitive storage elements; a plurality of bit/sense means coupling one terminal of each of said capacitive storage elements independently to an information input and output means; and switching means, responsive to a memory cell accessing signal, for unconditionally causing the other terminal of each of said capactive storage elements to be simultaneously coupled to a predetermined reference potential.
Claim 2
Dependent Claim 80 words
An information storage system including a plurality of addressable memory cells, each of said memory cells comprising: a plurality of two terminal capacitive storage elements; a plurality of bit/sense means coupling one terminal of each of said capacitive storage elements independently to an information input and output means; and switching means, responsive to a memory cell accessing signal, for unconditionally causing the other terminal of each of said capactive storage elements to be simultaneously coupled to a predetermined reference potential.
Claim 3
Dependent Claim 15 words
The information storage system of claim 1 wherein said switching means comprises a bipolar transistor.
Claim 4
Dependent Claim 34 words
The information storage system of claim 2 wherein said bipolar transistor includes a base, a collector and a plurality of emitters, each of said emitters forming said other terminal of said capacitive storage element.
Claim 5
Dependent Claim 19 words
The information storage system of claim 3 wherein said base is directly coupled to a source of accessing signals.
Claim 6
Dependent Claim 19 words
The information storage system of claim 4 wherein said collector is directly coupled to a source of accessing signals.
Claim 7
Dependent Claim 19 words
The information storage system of claim 5 wherein said bipolar transistor and said capacitive storage element are vertically aligned.
Claim 8
Dependent Claim 34 words
The information storage system of claim 6 wherein the junction capacitance between said base and each of said emitters is substantially equal in magnitude to the capacitance of one of said capacitive storage elements.
Claim 9
Dependent Claim 74 words
The information storage system of claim 1 wherein said switching means comprises a plurality of semiconductor regions of alternating first and second conductivity types forming a plurality of isolated metallurgical junctions, and further wherein said bit/sense lines are coupled to at least a plurality of said semiconductor regions of said first conductivity type and said accessing signal is applied between two adjacent regions to cause all of said metallurgical junctions to become forward biased.
Claim 10
Dependent Claim 28 words
The information storage system of claim 8 wherein at least some of said bit/sense lines are coupled to at least some of said regions of second conductivity type.
Claim 11
Dependent Claim 78 words
In an information storage system having a plurality of addressable memory cells coupled to a plurality of bit/sense lines, each memory cell comprising: a transistor having a collector, a base and a plurality of emitters; an information signal storing capacitor coupled between each of said emitters and a separate one of said bit/sense lines; and memory cell accessing means coupled to said collector and base for unconditionally causing transistor action in said transistor when said cell is addressed.
Claim 12
Dependent Claim 78 words
In an information storage system having a plurality of addressable memory cells coupled to a plurality of bit/sense lines, each memory cell comprising: a transistor having a collector, a base and a plurality of emitters; an information signal storing capacitor coupled between each of said emitters and a separate one of said bit/sense lines; and memory cell accessing means coupled to said collector and base for unconditionally causing transistor action in said transistor when said cell is addressed.
Claim 13
Dependent Claim 17 words
The information storage system of claim 10 wherein said collector is coupled to a fixed reference potential.
Claim 14
Dependent Claim 26 words
The information storage system of claim 10 wherein said memory cell accessing means comprises first and second addressing signals coupled, respectively, to said base and collector.
Claim 15
Dependent Claim 60 words
The information storage system of claim 10 wherein said memory cell accessing means comprises first address signal responsive means for selectively providing base current to said transistor and second address signal responsive means for selectively coupling said base current to a source of reference potential to prevent transistor action in said transistor when said memory cell is to be unselected.
Claim 16
Dependent Claim 32 words
The information storage system of claim 13 wherein said transistor is of a first conductivity type and said first address responsive means is a lateral bipolar transistor of a second conductivity type.
Claim 17
Dependent Claim 17 words
The information storage system of claim 14 wherein said second address signal responsive means comprises a diode.
Claim 18
Dependent Claim 162 words
An information storage system including a plurality of memory cells, each memory cell comprising: a plurality of bit/sense lines for transferring information signals to and from said memory cell; a plurality of first semiconductor regions of a first conductivity type, each of said first semiconductor regions forming at least one first PN junction with at least one second semiconductor region of a second conductivity type; a capacitive storage means associated with each of said first semiconductor regions, for storing information signals, each of said capacitive storage means being coupled to one of said bit/sense lines; a third semiconductor region of said first conductivity type forming a second PN junction with said one second semiconductor region; and means coupled to said bit/sense lines for sensing the presence of current flowing between each of said first semiconductor regions and said third semiconductor region when said second PN junction is forward biased, said current being representative of information signals stored in said capacitive storage means.
Claim 19
Dependent Claim 162 words
An information storage system including a plurality of memory cells, each memory cell comprising: a plurality of bit/sense lines for transferring information signals to and from said memory cell; a plurality of first semiconductor regions of a first conductivity type, each of said first semiconductor regions forming at least one first PN junction with at least one second semiconductor region of a second conductivity type; a capacitive storage means associated with each of said first semiconductor regions, for storing information signals, each of said capacitive storage means being coupled to one of said bit/sense lines; a third semiconductor region of said first conductivity type forming a second PN junction with said one second semiconductor region; and means coupled to said bit/sense lines for sensing the presence of current flowing between each of said first semiconductor regions and said third semiconductor region when said second PN junction is forward biased, said current being representative of information signals stored in said capacitive storage means.
Claim 20
Dependent Claim 54 words
The information storage system of claim 16 wherein each of said first semiconductor regions forms two separate first PN junctions with different ones of a plurality of said second semiconductor regions and said memory cell accessing means applies said biasing potentials directly to only said one second semiconductor region and said third semiconductor region.
Claim 21
Dependent Claim 23 words
The information storage system of claim 17 further including additional capacitive storage means coupled to at least some of said second semiconductor regions.
Claim 22
Dependent Claim 17 words
The information storage system of claim 18 wherein said semiconductor regions are formed on an insulating substrate.
Claim 23
Dependent Claim 33 words
The information storage system of claim 16 wherein there is provided only one second and one third semiconductor region and said first and second PN junctions are formed in a substantially vertical arrangement.
Claim 24
Dependent Claim 29 words
The information storage system of claim 20 wherein the junction capacitance of said first PN junctions is substantially equal in magnitude to the capacitance of said capacitive storage means.
Claim 25
Dependent Claim 127 words
In an integrated semiconductor memory system containing a plurality of addressable cells, each cell comprising: a substrate containing a first region of first conductivity type material; a second region of second conductivity type material forming a metallurgical junction with said first region; a plurality of third regions of said first conductivity type material formed within said second region and forming a plurality of separate metallurgical junctions therewith; a plurality of conductive members, each one of said conductive members being associated with, and insulatingly spaced from, one of said third regions; and accessing means for applying a forward bias voltage between said first and second regions to cause each of said third regions to be coupled to a reference potential whenever said memory cell is to be accessed.
Claim 26
Dependent Claim 127 words
In an integrated semiconductor memory system containing a plurality of addressable cells, each cell comprising: a substrate containing a first region of first conductivity type material; a second region of second conductivity type material forming a metallurgical junction with said first region; a plurality of third regions of said first conductivity type material formed within said second region and forming a plurality of separate metallurgical junctions therewith; a plurality of conductive members, each one of said conductive members being associated with, and insulatingly spaced from, one of said third regions; and accessing means for applying a forward bias voltage between said first and second regions to cause each of said third regions to be coupled to a reference potential whenever said memory cell is to be accessed.
Claim 27
Dependent Claim 24 words
The memory system of claim 22 wherein said first region of first conductivity type material is common to a plurality of said memory cells.
Claim 28
Dependent Claim 32 words
The memory system of claim 23 wherein each of said conductive members is associated with and insulatingly spaced from one of said third regions in each of said plurality of memory cells.
Claim 29
Dependent Claim 40 words
The memory system of claim 22 wherein the capacitance of said metallurgical junctions formed by said second and third regions is substantially equal in magnitude to the capacitance between each of said third regions and each of said conductive members.

References Cited (Backward Citations)

US3582909A Cited
US3614749A Cited
US3906296A Cited
US3838405A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-09-07 1980-03-08 1980-09-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-09-07 1984-03-08 1984-09-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-09-07 1988-03-08 1988-09-07 $7700.00 Window Closed / Lapsed

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