Patent US5037434A successfully refreshed from Google Patents.
US3710352A
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High speed-large storage capability electron beam accessed memory method and apparatus
Assignee: Micro-Bit Corp
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Filing: 1970-03-13
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Granted: 1973-01-09
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Expires: 1990-03-13
Abstract
Abstract A high speed memory using a thin film ferroelectric storage medium and high speed, selectively directed heating means in the form of an electron beam for selectively heating discrete bit storage areas on the ferroelectric storage medium to a temperature in the vicinity of the Curie point, and subsequently applying a low voltage polarizing potential across the ferroelectric storage medium during cooling of the selectively heated discrete bit storage areas below the Curie point whereby polarized charges are permanently frozen into the discrete areas selectively to form unique bits of recorded information. The low voltage polarizing potential is selectively reversible whereby different polarity charges may be formed at the selected different discrete areas on the ferroelectric storage medium. The ferroelectric storage medium preferably comprises a thin ferroelectric film, on the order of a few thousand angstroms thick which may be sandwiched between two thin metal films of several hundred angstrom units thickness, or alternatively may be sandwiched with a semiconductor layer between two thin metal films. Non-destructive read-out is accomplished by redirecting the electron-beam to a previously written polarized area to heat it below the Curie point and detecting the pyroelectric current. Alternatively, the read-out electron beam can be adjusted to probe the depletion and accumulation regions induced in the semiconductor layer by the polarized charges in the ferroelectric film. The electron beam writing and reading apparatus is of the type having a compound arrangement of a matrix of fine lenslets arrayed in a common plane with each lenslet having its own focusing and deflection system for focusing and directing the electron beam onto different discrete areas of the ferroelectric storage medium within an area of view unique to each lenslet. A suitable electron source followed by a coarse focusing and deflection system directs an electron beam to a selected one of the fine lenslets to activate that lenslet and selectively record a bit of information on the discrete area of the ferroelectric recording medium within the unique field of view of the selected lenslet. The memory is capable of storing 108 bits of information in discrete areas on the order of 1 micron in diameter over the surface of a ferroelectric storage medium approximately one centimeter by one centimeter square with recording/read out speeds of at least one bit per microsecond or faster. Extremely large, storage capability memory systems may be formed with such memories having a storage capacity on the order of 1010 bits randomly accessible at speeds of at least one bit per microsecond by including 102 high speed memory units constructed in the above-described manner arrayed in a common system and having a central common controller for accessing simultaneously each one of the high speed memory units in response to instructions from a computer system input-output equipment and supplying the selected infOrmation to an output circuit for connecting the output from each of the high speed memory units to the computer input-output equipment.
Inventors
- 👤 D Smith
- 👤 K Harte
- 👤 D Speliotis
- 👤 M Cohen
- 👤 S Newberry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:49
CPC Classifications
H; H01; H01J; H01J31/00; H01J31/08; H01J31/58; H01J31/60; G; G11; G11C; G11C13/00; G11C13/04; G11C13/047
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
105 words
A high speed memory including a ferroelectric storage medium having a thickness less than one micron, high speed, selectively directed electron beam heating means for selectively heating discrete storage areas on the ferroelectric storage medium to a temperature in the vicinity of the Curie point of the ferroelectric storage medium, and means for applying a low voltage polarizing potential of the order of 2 to 6 volts across the ferroelectric storage medium during cooling of the selectively heated discrete storage areas below the Curie point whereby a polarized charge is permanently frozen into each discrete area selectively to form a unique bit of recorded information.
Claim 2
Dependent Claim
105 words
A high speed memory including a ferroelectric storage medium having a thickness less than one micron, high speed, selectively directed electron beam heating means for selectively heating discrete storage areas on the ferroelectric storage medium to a temperature in the vicinity of the Curie point of the ferroelectric storage medium, and means for applying a low voltage polarizing potential of the order of 2 to 6 volts across the ferroelectric storage medium during cooling of the selectively heated discrete storage areas below the Curie point whereby a polarized charge is permanently frozen into each discrete area selectively to form a unique bit of recorded information.
Claim 3
Dependent Claim
46 words
A high speed memory according to claim 1 wherein the means for applying a low voltage polarizing potential is selectively reversible whereby different polarity charges may be formed at selected different discrete areas on the ferroelectric storage medium representing binary one and zero information bit sites.
Claim 4
Dependent Claim
33 words
A high speed memory according to claim 1 wherein the ferroelectric storage medium comprises a thin ferroelectric film on the order of a few thousand angstroms thick sandwiched between two thin metal films.
Claim 5
Dependent Claim
23 words
A high speed memory according to claim 3 wherein the ferroelectric film is formed from the class of materials comprising BaTiO3 and Pb(Ti.Zr.Sn)O3.
Claim 6
Dependent Claim
93 words
A high speed memory according to claim 1 further including means for deriving a reverse polarizing potential having a polarity opposite to that of the charge to be frozen-in a given information bit site at each selected discrete area, and means for applying said reverse polarizing potential across the ferroelectric storage medium during heating up of the selected discrete areas whereby the storage medium is subjected to alternate polarity polarizing potentials during the respective heating and cooling phases of each writing operation to thereby minimize disturbance effects on adjacent information bit site locations.
Claim 7
Dependent Claim
126 words
A high speed, large storage capability memory according to claim 1 wherein the electron beam writing apparatus is of the type having a compound arrangement of a matrix of fine lenslets arrayed in a common plane with each lenslet having its own focusing and deflection system for focusing and directing an electron beam onto different discrete areas of the ferroelectric storage medium within an area of view unique to each lenslet, and a coarse focusing and deflection system capable of focusing an electron beam from a suitable source and directing it to a selected fine lenslet for activating that lenslet and selectively recording a bit of information on a discrete area of the ferroelectric recording medium within the unique field of view of the selected lenslet.
Claim 8
Dependent Claim
56 words
A high speed memory according to claim 6 wherein the memory is capable of storing 108 bits of information in discrete areas on the order of 1 micron in diameter on the surface of a ferroelectric storage medium approximately one centimeter by 1 centimeter square and with recording speeds of at least one bit per microsecond.
Claim 9
Dependent Claim
33 words
A high speed memory according to claim 7 wherein the ferroelectric storage medium comprises a thin ferroelectric film on the order of a few thousand angstroms thick sandwiched between two thin metal films.
Claim 10
Dependent Claim
23 words
A high speed memory according to claim 8 wherein the ferroelectric film is formed from the class of materials comprising BaTiO3 and Pb(Ti.Zr.Sn)O3.
Claim 11
Dependent Claim
98 words
A high speed large storage capability memory system having a storage capacity on the order of 1010 bits randomly accessible at a speed of at least one bit per microsecond wherein there are 102 high speed memory units according to claim 9 arrayed in a common system and having a central common controller for accessing simultaneously each of the high speed memory units in response to instructions from a computer system input-output equipment and an output amplifier circuit connected to the output from each of the high speed memory units for supplying accessed information back to the computer.
Claim 12
Dependent Claim
93 words
A high speed memory according to claim 9 further including means for deriving a reverse polarizing potential having a polarity opposite to that of the charge to be frozen-in a given information bit site at each selected discrete area, and means for applying said reverse polarizing potential across the ferroelectric storage medium during heating up of the selected discrete areas whereby the storage medium is subjected to alternate polarity polarizing potentials during the respective heating and cooling phases of each writing operation to thereby minimize disturbance effects on adjacent information bit site locations.
Claim 13
Dependent Claim
40 words
A high speed large storage capability memory system wherein there are a multiplicity of high speed memory units according to claim 6 arrayed in a common system and having a central common controller for accessing the high speed memory units.
Claim 14
Dependent Claim
120 words
A high speed memory according to claim 6 wherein the electron beam writing apparatus is disposed within an evacuated housing including a source of electrons confronting the ferroelectric storage medium, and the coarse deflecting means comprises a single set of orthogonally acting deflecting elements for deflecting an electron beam from the source along mutually orthogonal axes for directing it to a selected fine lenslet, and wherein the electron beam writing apparatus further includes accelerating lens means positioned intermediate the coarse deflecting means and the matrix of fine lenslets for accelerating the electrons and straightening the beam to thereby cause it to enter the fine lenslets along an essentially orthogonal path relative to the plane of the matrix of fine lenslets.
Claim 15
Dependent Claim
70 words
A high speed memory according to claim 1 wherein the ferroelectric storage medium comprises a ferroelectric layer laminated with a semiconductor layer to form an interface whereby the polarized charges selectively written into the discrete areas comprising information bit sites on the ferroelectric layer induce corresponding depletion regions or accumulation regions in the semiconductor layer adjacent the interface dependent upon the polarity of the charges frozen into the ferroelectric layer.
Claim 16
Dependent Claim
46 words
A high speed memory according to claim 14 wherein the means for applying a low voltage polarizing potential is selectively reversible whereby different polarity charges may be formed at selected different discrete areas on the ferroelectric storage medium representing binary one and zero information bit sites.
Claim 17
Dependent Claim
126 words
A high speed, large storage capability memory according to claim 15 wherein the electron beam writing apparatus is of the type having a compound arrangement of a matrix of fine lenslets arrayed in a common plane with each lenslet having its own focusing and deflection system for focusing and directing an electron beam onto different discrete areas of the ferroelectric storage medium within an area of view unique to eaCh lenslet, and a coarse focusing and deflection system capable of focusing an electron beam from a suitable source and directing it to a selected fine lenslet for activating that lenslet and selectively recording a bit of information on a discrete area of the ferroelectric recording medium within the unique field of view of the selected lenslet.
Claim 18
Dependent Claim
43 words
A high speed large storage capability memory system wherein there are a multiplicity of high speed memory units according to claim 16 arrayed in a common system and having a central common controller for simultaneously accessing each of the high speed memory units.
Claim 19
Dependent Claim
80 words
A high speed write/read memory according to claim 1 wherein output means are connected across the ferroelectric storage medium for deriving output electric signals from the respective discrete storage areas upon the selectively directed electron beam heating means being redirected back to the selectively heated storage areas in a subsequent reading operation, the output electric signals having a polarity and magnitude representative of the unique bit of information previously recorded in the respective selected discrete areas during a writing operation.
Claim 20
Dependent Claim
41 words
A high speed write/read large storage capability memory system wherein there are a multiplicity of high speed memory units according to claim 18 arrayed in a common system and having a central common controller for accessing the high speed memory units.
Claim 21
Dependent Claim
118 words
A high speed write/read memory according to claim 1 further including output means connectable across at least the ferroelectric storage medium for deriving output electric signals from the respective discrete storage areas representing prerecorded information bit sites during a subsequent reading operation and means for adjusting the energy level of the selectively directed electron beam heating means to a value such that the respective discrete storage areas being read out are heated only to a temperature value below the Curie point during read-out whereby non-destructive read-out is achieved, and output electric signals having a polarity and magnitude representative of the unique bit of information previously recorded in the respective selected discrete areas, are supplied to the output means.
Claim 22
Dependent Claim
63 words
A high speed write/read memory according to claim 20 wherein the electric signals produced during read out are pyroelectric current signals produced as a result of the selective heating during reading of the polarized bit information sites to an increased temperature over ambient but below the Curie point of the ferroelectric storage medium whereby non-destructive read-out of the information previously recorded is accomplished.
Claim 23
Dependent Claim
47 words
A high speed write/read memory according to claim 21 wherein the means for applying a low voltage polarizing potential is selectively reversible whereby different polarity charges may be formed at selected different discrete areas on the ferroelectric storage medium representing binary one and zero information bit sites.
Claim 24
Dependent Claim
127 words
A high speed write/read, large storage capability memory according to claim 22 wherein the electron beam write/read apparatus is of the type having a compound arrangement of a matrix of fine lenslets arrayed in a common plane with each lenslet having its own focusing and deflection system for focusing and directing an electron beam onto different discrete areas of the ferroelectric storage medium within an area of view unique to each lenslet, and a coarse focusing and deflection system capable of focusing an electron beam from a suitable source and directing it to a selected fine lenslet for activating that lenslet and selectively recording a bit of information on a discrete area of the ferroelectric recording medium within the unique field of view of the selected lenslets.
Claim 25
Dependent Claim
57 words
A high speed write/read memory according to claim 23 wherein the memory is capable of storing 108 bits of information in discrete areas on the order of 1 micron in diameter on the surface of a ferroelectRic storage medium approximately one centimeter by 1 centimeter square and with recording speeds of at least one bit per microsecond.
Claim 26
Dependent Claim
34 words
A high speed write/read memory according to claim 24 wherein the ferroelectric storage medium comprises a thin ferroelectric film on the order of a few thousand angstroms thick sandwiched between two thin metal films.
Claim 27
Dependent Claim
24 words
A high speed write/read memory according to claim 25 wherein the ferroelectric film is formed from the class of materials comprising BaTiO3 and Pb(Ti.Zr.Sn)O3.
Claim 28
Dependent Claim
73 words
A high speed large storage capability write/read memory system having a storage capacity on the order of 1010 bits randomly accessible at a speed of at least one bit per microsecond wherein there are 102 high speed memory units according to claim 26 arrayed in a common system and having a central common controller simultaneously accessing each of the high speed memory units in response to instructions from a computer system input-output equipment.
Claim 29
Dependent Claim
94 words
A high speed write/read memory according to claim 26 further including means for deriving a reverse polarizing potential having a polarity opposite to that of the charge to be frozen-in a given information bit site at each selected discrete area, and means for applying said reverse polarizing potential across the ferroelectric storage medium during heating up of the selected discrete areas whereby the storage medium is subjected to alternate polarity polarizing potentials during the respective heating and cooling phases of each writing operation to thereby minimize disturbance effects on adjacent information bit site locations.
Claim 30
Dependent Claim
126 words
A high speed write/read memory according to claim 20 wherein the ferroelectric storage medium includes a ferroelectric layer laminated with a semiconductor layer to form an interface and the polarized charges selectively written into the discrete areas comprising bit information sites on the ferroelectric layer induce corresponding depletion regions or accumulation regions in the semiconductor layer adjacent the interface dependent upon the polarity of the charges frozen into the ferroelectric layer and wherein the selectively directed electron beam heating means comprises an electron beam write/read apparatus adjusted to selectively probe the semiconductor layer depletion regions and accumulation regions adjacent the interface with the ferroelectric layer during read-out to derive output electric signals representative of the information stored in the charge pattern formed on the ferroelectric layer.
Claim 31
Dependent Claim
47 words
A high speed write/read memory according to claim 29 wherein the means for applying a low voltage polarizing potential is selectively reversible whereby different polarity charges may be formed at selected different discrete areas on the ferroelectric storage medium representing binary one and zero information bit sites.
Claim 32
Dependent Claim
127 words
A high speed write/read, large storage capability memory according to claim 30 wherein the electron beam write/read apparatus is of the type having a compound arrangement of a matrix of fine lenslets arrayed in a common plane with each lenslet having its own focusing and deflection system for focusing and directing an electron beam onto different discrete areas of the ferroelectric storage medium within an area of view unique to each lenslet, and a coarse focusing and deflection system capable of focusing an electron beam from a suitable source and directing it to a selected fine lenslet for activating that lenslet and selectively recording a bit of information on a discrete area of the ferroelectric recording medium within the unique field of view of the selected lenslet.
Claim 33
Dependent Claim
65 words
A high speed write/read memory according to claim 31 wherein the ferroelectric storage medium comprises a thin ferroelectric film on the order of a few thousand angstrom units thick formed on a semiconductor substrate to define the interface and thin metal films on the order of 500 to 1000 Angstrom units thick formed on the remaining surfaces of the ferroelectric film and the semiconductor substrate.
Claim 34
Dependent Claim
57 words
A high speed write/read memory according to claim 32 wherein the memory is capable of storing 108 bits of information in discrete areas on the order of 1 micron in diameter on the surface of a ferroelectric storage medium approximately 1 centimeter by 1 centimeter square and with recording speeds of at least one bit per microsecond.
Claim 35
Dependent Claim
24 words
A high speed write/read memory according to claim 33 wherein the ferroelectric film is formed from the class of materials comprising BaTiO3 and Pb(Ti.Zr.Sn)O3.
Claim 36
Dependent Claim
72 words
A high speed write/read large storage capability memory system having a storage capacity on the order of 1010 bits randomly accessible at a speed of one bit per microsecond wherein there are 102 high speed memory units according to claim 34 arrayed in a common system and having a central common controller for accessing simultaneously each of the high speed memory units in response to instructions from a computer system input-output equipment.
Claim 37
Dependent Claim
94 words
A high speed write/read memory according to claim 34 further including means for deriving a reverse polarizing potential having a polarity opposite to that of the charge to be frozen-in a given information bit site at each selected discrete area, and means for applying said reverse polarizing potential across the ferroelectric storage medium during heating up of the selected discrete areas whereby the storage medium is subjected to alternate polarity polarizing potentials during the respective heating and cooling phases of each writing operation to thereby minimize disturbance effects on adjacent information bit site locations.
Claim 38
Independent Claim
96 words
The method of permanently recording information on a ferroelectric storage medium having a thickness less than 1 micron with a selectively directed beam of electrons for heating the medium to a temperature at or above the Curie point of the ferroelectric storage medium and thereafter sequentially applying a low voltage polarizing potential of the order of 2-6 volts across the ferroelectric storage medium during cooling of the selectively heated discrete storage areas below the Curie point whereby a polarized charge is permanently frozen into each discrete area selectively to form a unique bit of recorded information.
Claim 39
Independent Claim
96 words
The method of permanently recording information on a ferroelectric storage medium having a thickness less than 1 micron with a selectively directed beam of electrons for heating the medium to a temperature at or above the Curie point of the ferroelectric storage medium and thereafter sequentially applying a low voltage polarizing potential of the order of 2-6 volts across the ferroelectric storage medium during cooling of the selectively heated discrete storage areas below the Curie point whereby a polarized charge is permanently frozen into each discrete area selectively to form a unique bit of recorded information.
Claim 40
Dependent Claim
76 words
The method set forth in claim 37 wherein the electron beam probe is finely focused and directed through the combined action of compound serially arranged focusing and deflecting fields whereby large storage capability on the order of 108 bits is achieved on discrete areas of the ferroelectric storage medium with each bit site being on the order of 1 micron in diameter and storage can be accomplished at speeds of at least 1 bit per microsecond.
Claim 41
Dependent Claim
65 words
The method set forth in claim 37 further including selectively heating the polarized bit information containing discrete areas on the ferroelectric storage medium with a selectively directed beam of electrons in a subsequent reading operation to an increased temperature below the Curie point to thereby derive pyroelectric current output signals whose polarity and magnitude are representative of the information recorded during a previous writing operation.
Claim 42
Dependent Claim
57 words
The method set forth in claim 37 further including reversing the polarity of the low voltage polarizing potential applied during cooling at the different discrete areas whereby different polarity charges are formed at the different selected discrete areas on the ferroelectric storage medium to thereby form a pattern of binary one and binary zero information bit sites.
Claim 43
Dependent Claim
69 words
The method set forth in claim 40 wherein the ferroelectric storage medium comprises a ferroelectric layer laminated with a semiconductor layer to form an interface and the polarized charges selectively written into the discrete areas comprising information bit sites on the ferroelectric layer induce corresponding depletion regions or accumulation regions in the semiconductor layer adjacent the interface dependent upon the polarity of the charges frozen into the ferroelectric layer.
Claim 44
Dependent Claim
53 words
The method set forth in claim 41 further including selectively probing the semiconductor layer depletion regions and accumulation regions adjacent the interface with the selectively directed beam of electrons during a subsequent read-out operation to derive output electric signals representative of the information stored in the charge pattern formed on the ferroelectric layer.
Claim 45
Dependent Claim
85 words
The method set forth in claim 40 wherein a polarizing potential is applied to the ferroelectric storage member during heating up of the selected discrete areas which is reverse in polarity to the polarizing potential applied during cooling and hence to the polarity of the charge frozen-in at a given information bit site whereby the storage medium is subjected to alternate polarity polarizing potentials during the respective heating and cooling phases of each writing operation to thereby minimize disturbance effects on adjacent information bit sites.
Claim 46
Dependent Claim
95 words
A ferroelectric/semiconductor information storage member comprising a thin ferroelectric layer laminated with a semiconductor layer to form an interface and having thin metal films formed on the remaining flat surfaces only of the ferroelectric layer and the semiconductor layer, respectively to thereby form a metal-ferroelectric-semiconductor-metal capacitor sandwich memory structure, the ferroelectric layer comprising a ferroelectric film having a thickness of a few thousand angstroms formed on a bulk semiconductor substrate having a thickness on the order of 0.2 millimeters and the metal films have a thickness on the order of 100 to 500 angstrom units.
Claim 47
Dependent Claim
95 words
A ferroelectric/semiconductor information storage member comprising a thin ferroelectric layer laminated with a semiconductor layer to form an interface and having thin metal films formed on the remaining flat surfaces only of the ferroelectric layer and the semiconductor layer, respectively to thereby form a metal-ferroelectric-semiconductor-metal capacitor sandwich memory structure, the ferroelectric layer comprising a ferroelectric film having a thickness of a few thousand angstroms formed on a bulk semiconductor substrate having a thickness on the order of 0.2 millimeters and the metal films have a thickness on the order of 100 to 500 angstrom units.
Claim 48
Dependent Claim
25 words
A ferroelectric/semiconductor information storage member according to claim 44 wherein the ferroelectric film is formed from the class of materials consisting of BaTiO3 and Pb(Ti.Zr.Sn)O3.
Claim 49
Dependent Claim
39 words
A ferroelectric/semiconductor information storage member according to claim 45 wherein one of the metal films includes a plurality of discontinuities which divide the layer into a plurality of electrically isolated conductive lands for respective connection to different output circuits.
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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) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |