US3886530A — Signal storage device

Claim 1

Independent Claim 122 words

A device for detecting stored information represented by stored electrical charge comprising, an interface formed between a semiconductor material and an insulaTor material, means for reversibly changing the electric charge stored in a given area of said insulator material adjacent the interface, in representation of said information, said electric charge change being sufficient to produce a change in a space charge region in the semiconductor material in registration with the given area in representation of said information, signal detecting means coupled to the device for detecting current flow across the interface, and means for producing and directing an electron beam into said space charge region in the semiconductor producing a transient current signal in the detecting means representative of said stored information.

Claim 2

Independent Claim 122 words

A device for detecting stored information represented by stored electrical charge comprising, an interface formed between a semiconductor material and an insulaTor material, means for reversibly changing the electric charge stored in a given area of said insulator material adjacent the interface, in representation of said information, said electric charge change being sufficient to produce a change in a space charge region in the semiconductor material in registration with the given area in representation of said information, signal detecting means coupled to the device for detecting current flow across the interface, and means for producing and directing an electron beam into said space charge region in the semiconductor producing a transient current signal in the detecting means representative of said stored information.

Claim 3

Dependent Claim 81 words

A device as in claim 1 and in which, the semiconductor material is p-type, said stored electric charge is changed positive producing a depletion space charge region in the semiconductor material adjacent the interface and the electron beam is directed into the depletion region exciting electrons into the semiconductor conduction band and producing holes in the semiconductor valence band both of which are swept from the region by the electric field associated with the depletion region producing the transient current signal.

Claim 4

Dependent Claim 35 words

A device as in claim 1 and in which, means are provided for producing a controlled electric field in said materials directed across the interface and the controlled field is synchronized with the electron beam.

Claim 5

Dependent Claim 38 words

A device as in claim 1 and in which, the detecting means detects a transient current peak produced when simultaneously the beam is directed to the depletion region and a controlled electric field is produced across the interface.

Claim 6

Dependent Claim 21 words

A device as in claim 4 and in which, the current peak is substantially greater than the simultaneous electron beam current.

Claim 7

Dependent Claim 33 words

A device as in claim 3 and in which, the stored electric charge is positive, the semiconductor material is p-type, and the controlled electric field direction is from the insulator toward the semiconductor.

Claim 8

Dependent Claim 57 words

A device as in claim 1 and in which, the insulator material is formed in a layer on a surface of a body of the semiconductor material and a layer of conductive material is formed on the insulator layer, the thickness of the insulator layer being at least determinative of the rate of response of the device.

Claim 9

Dependent Claim 15 words

A device as in claim 7 and in which, the semiconductor material is p-type Si.

Claim 10

Dependent Claim 14 words

A device as in claim 8 and in which, the insulator material is SiO2.

Claim 11

Dependent Claim 43 words

A device as in claim 9 and in which the SiO2 thickness is about 1000A*, the conductive material is Al of thickness about 500A*, and the electron beam is of sufficient energy to penetrate the Al and SiO2 layers and into the Si.

Claim 12

Independent Claim 135 words

A device for storing electric signals and then detecting the stored signals in response to an incident electron beam comprising, an interface formed between a semiconductive material and an insulator material, means for producing a controlled electric field in said materials across said interface, means for producing and directing an electron beam into a given area of said materials during one interval at the same time said electric field is produced of suitable magnitude and direction to cause a reversible change in the electrical charge stored in said insulator material adjacent the interface representation of said information, signal detecting means coupled to said device, and means for directing said electron beam into the same given area of said materials during another interval producing a transient signal in said detecting means representative of said stored information.

Claim 13

Independent Claim 135 words

A device for storing electric signals and then detecting the stored signals in response to an incident electron beam comprising, an interface formed between a semiconductive material and an insulator material, means for producing a controlled electric field in said materials across said interface, means for producing and directing an electron beam into a given area of said materials during one interval at the same time said electric field is produced of suitable magnitude and direction to cause a reversible change in the electrical charge stored in said insulator material adjacent the interface representation of said information, signal detecting means coupled to said device, and means for directing said electron beam into the same given area of said materials during another interval producing a transient signal in said detecting means representative of said stored information.

Claim 14

Dependent Claim 76 words

A device as in claim 11 and in which, said stored electric charge modifies a depletion region in the semiconductor material adjacent to the interface and the electron beam during the other interval penetrates into the depletion region creAting electron-hole pairs which are separated and swept from the region by the electric field associated with the depletion region producing the transient signal as a transient current pulse peak which is conducted to the signal detecting means.

Claim 15

Dependent Claim 21 words

A device as in claim 12 and in which, the current peak is substantially greater than the simultaneous electron beam current.

Claim 16

Dependent Claim 33 words

A device as in claim 11 and in which, the stored electric charge is positive, the semiconductor material is p-type, and the controlled electric field direction is from the insulator toward the semiconductor.

Claim 17

Dependent Claim 58 words

A device as in claim 11 and in which, the insulator material is formed in a layer on a surface of a body of the semiconductor material and a layer of conductive material is formed on the insulator layer, the thickness of the insulator layer being at least partially determinative of the rate of response of the device.

Claim 18

Dependent Claim 15 words

A device as in claim 15 and in which, the semiconductor material is p-type Si.

Claim 19

Dependent Claim 14 words

A device as in claim 16 and in which, the insulator material is SiO2.

Claim 20

Dependent Claim 53 words

A device as in claim 17 and in which, the SiO2 thickness is about 1000A*, the conductive material is Al of thickness about 500A*, and the electron beam directed into the given area during the other interval is of sufficient energy to penetrate through the Al and SiO2 layers and into the Si.

Claim 21

Dependent Claim 49 words

A device as in claim 11 and in which, the stored and detected signals are binary, the existence of stored positive electrical charge at the given area represents storage of one binary condition and the lack of stored electrical charge at the given area represents the other binary condition.

Claim 22

Dependent Claim 47 words

A device as in claim 19 and in which, the semiconductor material is p-type and said transient signal produced during said other interval is substantially larger when a binary one is stored at the given area than when a binary zero is stored at the given area.

Claim 23

Dependent Claim 47 words

A device as in claim 19 and in which, the semiconductor material is n-type and said transient signal produced during said other interval is substantially smaller when a binary one is stored at the given area than when a binary zero is stored at the given area.

Claim 24

Dependent Claim 22 words

A device as in claim 19 and in which, a controlled electric field is applied across said interface during the other interval.

Claim 25

Dependent Claim 37 words

A device as in claim 20 and in which, a controlled electric field is applied across said interface during the other interval, and the direction of said field being from the insulator material toward the semiconductor material.

Claim 26

Dependent Claim 37 words

A device as in claim 21 and in which, a controlled electric field is applied across said interface during the other interval, and the direction of said field being from the semiconductor material toward the insulator material.

Claim 27

Dependent Claim 32 words

A device as in claim 11 and in which, the semiconductor and insulator materials are sandwiched between electrically conductive layers and said detecting means is coupled to one of said conductive layers.

Claim 28

Dependent Claim 90 words

A device as in claim 25 further including, a cathode ray tube, the sandwich is the target in the cathode ray tube and the electron beam is produced in the cathode ray tube, means are provided for directing the beam to different areas of the sandwich lying in the plane of the interface, and means are provided for energizing the beam, whereby said electrical charge is selectively stored at different areas and said detected signal produced when the beam is directed to a selected area is representative of said selectivity.

Claim 29

Dependent Claim 57 words

A device as in claim 26 and in which, the stored and detected signals signify binary values, the existence of stored electrical charge at a given area represents storage of one binary condition at that area and the lack of stored electrical charge at a given area Represents storage of the other binary condition at that area.

Claim 30

Dependent Claim 40 words

A device as in claim 26 and including means for synchronizing the controlled electric field and the beam to store a charge pattern in the plane of the sandwich and to detect the stored charge pattern or any part thereof.

Claim 31

Dependent Claim 31 words

A device as in claim 27 and including means for controlling the electric field when the binary condition of storage at a given area is detected to restore the said condition.

Claim 32

Dependent Claim 190 words

A computer memory element for storing binary data in the form of electric charge patterns comprising, a conductive back layer, a semiconductor layer, an insulator layer, and a conductive front layer arranged in the order named in the form of a sandwich with the semiconductor layer and insulator layer forming an interface, the conductive back layer covering substantially the entire surface of the semiconductor layer opposite the interface, the conductive front layer covering substantially the entire surface of the insulator layer opposite the interface, signal detecting means coupled to at least one of said conductive layers, means for generating and directing a write electron beam into given areas of the insulator layer in the presence of an electric field across the sandwich, reversibly changing stored electric charge in said given areas and producing a change in a depletion region in the semiconductor layer adjacent the interface in registration with the stored charge, said depletion region being representative of the binary data, and means for generating and directing a read electron beam into the depletion region producing a transient pulse signal to the detecting means representative of said stored binary data.

Claim 33

Dependent Claim 190 words

A computer memory element for storing binary data in the form of electric charge patterns comprising, a conductive back layer, a semiconductor layer, an insulator layer, and a conductive front layer arranged in the order named in the form of a sandwich with the semiconductor layer and insulator layer forming an interface, the conductive back layer covering substantially the entire surface of the semiconductor layer opposite the interface, the conductive front layer covering substantially the entire surface of the insulator layer opposite the interface, signal detecting means coupled to at least one of said conductive layers, means for generating and directing a write electron beam into given areas of the insulator layer in the presence of an electric field across the sandwich, reversibly changing stored electric charge in said given areas and producing a change in a depletion region in the semiconductor layer adjacent the interface in registration with the stored charge, said depletion region being representative of the binary data, and means for generating and directing a read electron beam into the depletion region producing a transient pulse signal to the detecting means representative of said stored binary data.

Claim 34

Dependent Claim 46 words

A memory element according to claim 30 further including, terminal lead means for respective electrical connection of a source of electric energy across the conductive back layer and the conductive front layer, thereby producing an electric field across substantially the entire cross section of the sandwich.

Claim 35

Dependent Claim 39 words

A memory element according to claim 30 wherein, the conductive front layer and insulating layer have thicknesses and are constituted in a manner such that the combined layers can be penetrated by an electron beam of moderate energy level.

Claim 36

Dependent Claim 69 words

A memory element according to claim 30 wherein, the impingement of the read electron beam into the depletion region of the semiconductor layer adjacent the given charge areas of the insulator layer produces electron-hole pairs which are separated and swept from the region by the electric field associated with the depletion region producing said transient pulse signal as a transient current pulse which is representative of the stored charge.

Claim 37

Dependent Claim 14 words

A memory element according to claim 33 wherein, the semiconductor material is p-type silicon.

Claim 38

Dependent Claim 15 words

A memory element according to claim 34 wherein, the insulator material is silicon dioxide (SiO2).

Claim 39

Dependent Claim 23 words

A memory element according to claim 35 wherein, the front conductive layer is aluminum having thickness of about 500 angstrom units (500 A*).

Claim 40

Dependent Claim 45 words

A memory element according to claim 36 wherein, the silicon dioxide (SiO2) layer has a thickness of about 1000 angstrom units (1000 A*) and the combined conductive front layer and insulating layer are capable of being penetrated by an electron beam of moderate energy level.

Claim 41

Independent Claim 152 words

A system for storing binary information comprising, cathode ray tube, a sandwich of contiguous layers of electrical semiconductor, insulator and conductor materials, in that order, at the target of the tube, an output circuit electrically coupled to the sandwich, circuits for controlling the position and intensity of the electron beam in the tube, means for causing electrical charge to be reversibly stored at discrete points in the plane of the sandwich in the insulator layer, said stored electrical charge producing a space charge region in the semiconductor material adjacent the interface between the semiconductor and insulator materials and means for directing the electron beam into the space charge region exciting electrons into the semiconductor conduction band and producing holes in the semiconductor valence band which are swept from the region by the electric field associated with the space charge region producing a transient current pulse which is conducted to the output circuit.

Claim 42

Independent Claim 152 words

A system for storing binary information comprising, cathode ray tube, a sandwich of contiguous layers of electrical semiconductor, insulator and conductor materials, in that order, at the target of the tube, an output circuit electrically coupled to the sandwich, circuits for controlling the position and intensity of the electron beam in the tube, means for causing electrical charge to be reversibly stored at discrete points in the plane of the sandwich in the insulator layer, said stored electrical charge producing a space charge region in the semiconductor material adjacent the interface between the semiconductor and insulator materials and means for directing the electron beam into the space charge region exciting electrons into the semiconductor conduction band and producing holes in the semiconductor valence band which are swept from the region by the electric field associated with the space charge region producing a transient current pulse which is conducted to the output circuit.

Claim 43

Dependent Claim 37 words

A system as in claim 38 and in which, means are provided for producing a controlled electric field in the sandwich of materials directed across said interface and the controlled field is synchronized with the electron beam.

Claim 44

Dependent Claim 26 words

A device as in claim 1 and in which, the space charge region in the semiconductor is a depletion region when the transient signal is detected.

Claim 45

Dependent Claim 28 words

A device as in claim 40 and in which, the transient signal is a current peak which is detected when the beam is directed to the depletion region.

Claim 46

Dependent Claim 87 words

A device as in claim 1 and in which, the semiconductor material is n-type, said stored electric charge is changed negative producing a depletion space charge region in the semiconductor material adjacent the interface and the electron beam is directed into the depletion region exciting electrons into the semiconductor conduction band and producing holes in the semiconductor valence band which are swept from the region by the electric field associated with the depletion region producing a transient current pulse which is conducted to the signal detecting means.

Claim 47

Dependent Claim 17 words

A system as in claim 38 and in which the space charge region is a depletion region.

Claim 48

Independent Claim 201 words

A system for storing binary information comprising, a cathode ray tube, a sandwich of contiguous layers of electrical semiconductor, insulator and conductor materials, in that order, at the target of the tube, an output circuit electrically coupled to the sandwich, circuits for controlling the position and intensity of the electron beam in the tube, an input circuit electrically coupled to the beam control circuits, a source of input signals, means for directing the electron beam to the sandwich during a write-in interval to reversibly store electrical charge at discrete points in the plane of the sandwich in the insulator layer in response to the input signals applied to the input circuit, said stored electrical charge producing a space charge region in the semiconductor material adjacent the interface between the semiconductor and insulator materials and means for directing the electron beam into the space charge region during a read-out interval exciting electrons into the semiconductor conduction band and producing holes in the semiconductor valence band which are swept from the region by the electric field associated with the depletion region producing a transient current pulse which is conducted to the output circuit during a read-out interval in representation of said stored charge.

Claim 49

Independent Claim 201 words

A system for storing binary information comprising, a cathode ray tube, a sandwich of contiguous layers of electrical semiconductor, insulator and conductor materials, in that order, at the target of the tube, an output circuit electrically coupled to the sandwich, circuits for controlling the position and intensity of the electron beam in the tube, an input circuit electrically coupled to the beam control circuits, a source of input signals, means for directing the electron beam to the sandwich during a write-in interval to reversibly store electrical charge at discrete points in the plane of the sandwich in the insulator layer in response to the input signals applied to the input circuit, said stored electrical charge producing a space charge region in the semiconductor material adjacent the interface between the semiconductor and insulator materials and means for directing the electron beam into the space charge region during a read-out interval exciting electrons into the semiconductor conduction band and producing holes in the semiconductor valence band which are swept from the region by the electric field associated with the depletion region producing a transient current pulse which is conducted to the output circuit during a read-out interval in representation of said stored charge.

Claim 50

Dependent Claim 64 words

A system as in claim 43 and in which, the input signals are of two kinds, the write-in and the read-out, the write-in input signals determine the pattern of storage points in the plane of the sandwich and the read-out input signals determine the points in the sandwich to which the beam is directed to produce the representative transient signals in the output circuit.

Claim 51

Dependent Claim 30 words

A system as in claim 44 and in which, the write-in and the read-out input signals are effective at different intervals defined as the write-in and the read-out intervals, respectively.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-05-26	1978-11-25	1979-05-27	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-05-26	1982-11-25	1983-05-27	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-05-26	1986-11-25	1987-05-27	$7700.00	Window Closed / Lapsed

Signal storage device

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag