US3701979A
Expired / Lapsed
US
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Slow write-fast read memory method and system
Assignee: Micro-Bit Corp
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Filing: 1970-01-09
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Granted: 1972-10-31
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Expires: 1990-01-09
Abstract
Abstract A slow write-fast read out information storage and retrieval method and system is described for use as a computer memory. The method and system employs a memory element comprising a conductive back layer, a semiconductor layer and an insulator enriched with an additive polarizing material such as the alkali metals sodium or lithium and a conductive front layer arranged in the order named in the form of a sandwich with the semiconductor layer and polarizing material enriched insulator layer forming an interface. By selectively heating discrete different locations on the memory element with a directed electron beam in accordance with the intelligence to be recorded, and applying a polarizing electric potential across the memory element which maintains the insulator layer positive with respect to the semiconductor layer concurrently with the selective heating, positive electric charges (which are non-destructive during read-out) will be formed in the insulator layer due to mobile ions of the additive alkali metal polarizing material which are transported to the interface as a result of the polarizing potential. The positive electric charges in turn produce space charge regions in the semiconductor layer adjacent to the interface at the selectively heated different discrete locations. If the semiconductor layer is a p-type semiconductor, the space charge region is a depletion region. If the semiconductor layer is a n-type semiconductor, the space charge region will be an accumulation region. By subsequently allowing the insulator layer to cool, the mobile ion charges thus transported to the interface at the selectively heated locations will be frozen in to thereby form selectively located, semi-permanent, space charge regions in the semiconductor layer whereby the intelligence to be recorded is embodied in the selectively located charges. In a subsequent reading operation, a read-out electron beam is caused to penetrate through the insulator layer and interface to the space charge region of the semiconductor layer where it will produce electron-hole carriers in the space charge region. To facilitate the reading operation, a polarizing, reading potential may be applied across the memory element simultaneously with the readout electron beam. In the selectively located space charge regions, a considerably increased electron-hole pair current will be produced compared to that normally induced by the electron beam itself in those regions which have not been selectively polarized. Consequently a pulsed current output can be derived during the reading operation which is indicative of the data or intelligence stored in the memory element.
Inventors
- 👤 Donald O Smith
- 👤 Kenneth J Harte
- 👤 Mitchell S Cohen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:05
CPC Classifications
H; H01; H01J; H01J31/00; H01J31/08; H01J31/58; H01J31/60; G; G11; G11C; G11C13/00; G11C13/04; G11C13/048; H01J29/00; H01J29/02; H01J29/10; H10; H10W; H10W74/00; H10W74/40; H10W74/43
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
205 words
An updatable write/erase-information storage method for subsequent fAst read-out in conjunction with computers and the like and employing a memory element comprising a conductive back layer, a semiconductor layer, an insulator enriched with an additive polarizing material and a conductive front layer arranged in the order named in the form of a sandwich with the semiconductor layer and polarizing material enriched insulator layer forming an interface, the method comprising selectively heating discrete different locations on the memory element in accordance with intelligence to be recorded, applying a polarizing writing potential across the memory element concurrently with the selective heating which polarizes the insulator layer positive with respect to the semiconductor layer to thereby form positive electric charges due to mobile ions of the additive polarizing material in the insulator layer adjacent the interface and results in enhanced space charge regions being formed in the semiconductor layer adjacent the interface at the selectively heated different discrete locations, and subsequently cooling the selectively heated different discrete locations to ambient temperature while maintaining the polarizing potential to thereby freeze in the selectively located positive electric charges in the insulator layer and resulting selectively located enhanced space charge regions in the semiconductor layer to thereby permanently record the intelligence.
Claim 2
Dependent Claim
205 words
An updatable write/erase-information storage method for subsequent fAst read-out in conjunction with computers and the like and employing a memory element comprising a conductive back layer, a semiconductor layer, an insulator enriched with an additive polarizing material and a conductive front layer arranged in the order named in the form of a sandwich with the semiconductor layer and polarizing material enriched insulator layer forming an interface, the method comprising selectively heating discrete different locations on the memory element in accordance with intelligence to be recorded, applying a polarizing writing potential across the memory element concurrently with the selective heating which polarizes the insulator layer positive with respect to the semiconductor layer to thereby form positive electric charges due to mobile ions of the additive polarizing material in the insulator layer adjacent the interface and results in enhanced space charge regions being formed in the semiconductor layer adjacent the interface at the selectively heated different discrete locations, and subsequently cooling the selectively heated different discrete locations to ambient temperature while maintaining the polarizing potential to thereby freeze in the selectively located positive electric charges in the insulator layer and resulting selectively located enhanced space charge regions in the semiconductor layer to thereby permanently record the intelligence.
Claim 3
Dependent Claim
74 words
An updatable write/erase information storage method according to claim 1 further including switching the polarizing potential across the memory element to a different polarity and/or value de-polarizing potential and concurrently selectively heating the discrete different locations on the memory element and subsequently cooling the selectively heated discrete different locations to ambient temperature while maintaining the de-polarizing potential to thereby erase the positive electric charges previously formed in the insulator layer in a recording step.
Claim 4
Dependent Claim
46 words
An updatable write/erase information storage method according to claim 2 wherein the selective heating is accomplished with a finely focused scanning electron beam impinging on discrete different locations of the memory element for discrete write/erase time intervals where it is desired selectively to write or erase.
Claim 5
Dependent Claim
37 words
An updatable write/erase information storage method according to claim 3 wherein the insulating layer of the memory element is selected from the class of materials including SiO2 and SiO, and the polarizing material is an alkali metal.
Claim 6
Dependent Claim
25 words
An updatable write/erase information storage method according to claim 4 wherein the alkali metal polarizing material is from the group consisting of sodium and lithium.
Claim 7
Dependent Claim
92 words
An updatable write/erase-fast read only information storage and retrieval method according to claim 3 further including increasing the penetrating power of the scanning electron beam to cause it to penetrate through the insulator layer and interface to the adjacent space charge region of the semiconductor layer to thereby produce electron-hole carriers in the region, simultaneously sweeping out the electron-hole carriers to produce output signal pulses, and detecting the resulting electron-hole carrier output signal pulses from the different discrete locations on the memory element as they are probed by the scanning electron beam.
Claim 8
Dependent Claim
42 words
An updatable write/erase-fast read only information storage and retrieval method according to claim 6 wherein the insulating layer of the memory element is selected from the class of materials consisting of SiO2 and SiO and the polarizing material is an alkali metal.
Claim 9
Dependent Claim
28 words
An updatable write/erase-fast read only information storage and retrieval method according to claim 7 wherein the alkali metal polarizing material from the group consisting of sodium and lithium.
Claim 10
Dependent Claim
72 words
An updatable write/erase-fast read only information storage and retrieval method according to claim 8 wherein the semiconductor layer is a p-type semiconductor and the enhanced space charGe regions comprise depletion regions, and enhanced positive polarity electron-hole current pulses are produced at those different discrete enhanced depletion region locations on the memory element where enhanced electric charges selectively were formed in the insulator in accordance with the intelligence recorded during the writing operation.
Claim 11
Dependent Claim
91 words
An updatable write/erase-fast read only information storage and retrieval method according to claim 8 wherein the semiconductor layer is an n-type semiconductor and the enhanced space charge regions comprise accumulation regions, a polarizing reading potential which is negative in polarity is applied across the sandwich whereby the insulator layer is negative relative to the semiconductor layer, and reduced negative polarity electron-hole current pulses are produced at those different discrete enhanced accumulation region locations on the memory element where enhanced electric charges selectively were formed in the insulator during the writing operation.
Claim 12
Dependent Claim
202 words
An updatable write/erase information storage apparatus comprising a memory element having a conductive back layer, a semiconductor layer, an insulator enriched with an additive polarizing material and a conductive front layer arranged in the order named in the form of a sandwich with the semiconductor layer and polarizing material enriched insulator layer forming an interface, selective heating means for selectively heating discrete different locations on the memory element in accordance with intelligence to be recorded, write biasing means for applying a polarizing writing potential across the memory element concurrently with the selective heating and which polarizes the insulator layer positive with respect to the semiconductor layer to thereby form positive electric charges due to mobile ions of the additive polarizing material in the insulator layer adjacent the interface and results in enhanced space charge regions being formed in the semiconductor layer adjacent the interface at the selectively heated different discrete locations, and means for subsequently cooling the selectively heated different discrete locations to ambient temperature while maintaining the polarizing writing potential to freeze in the selectively located positive electric charges in the insulator layer and resulting selectively located enhanced space charge regions in the semiconductor layer to thereby permanently record the intelligence.
Claim 13
Dependent Claim
202 words
An updatable write/erase information storage apparatus comprising a memory element having a conductive back layer, a semiconductor layer, an insulator enriched with an additive polarizing material and a conductive front layer arranged in the order named in the form of a sandwich with the semiconductor layer and polarizing material enriched insulator layer forming an interface, selective heating means for selectively heating discrete different locations on the memory element in accordance with intelligence to be recorded, write biasing means for applying a polarizing writing potential across the memory element concurrently with the selective heating and which polarizes the insulator layer positive with respect to the semiconductor layer to thereby form positive electric charges due to mobile ions of the additive polarizing material in the insulator layer adjacent the interface and results in enhanced space charge regions being formed in the semiconductor layer adjacent the interface at the selectively heated different discrete locations, and means for subsequently cooling the selectively heated different discrete locations to ambient temperature while maintaining the polarizing writing potential to freeze in the selectively located positive electric charges in the insulator layer and resulting selectively located enhanced space charge regions in the semiconductor layer to thereby permanently record the intelligence.
Claim 14
Dependent Claim
90 words
An updatable write/erase information storage apparatus according to claim 11 further including switching means for switching the polarizing potential across the memory element to a different polarity and/or value de-polarizing potential, means for selectively heating the discrete different locations to be erased on the memory element concurrently with the application of the de-polarizing potential, and means for subsequently cooling the selectively heated discrete different locations to ambient temperature while maintaining the de-polarizing potential to thereby erase the positive electric charges previously formed in the insulator layer in a recording step.
Claim 15
Dependent Claim
57 words
An updatable write/erase information storage apparatus according to claim 12 wherein the selective heating means comprises a scanning electron beam writing device for producing a finely focused scanning electron beam that is caused to impinge on discrete different locations of the memory element for discrete write/erase time intervals where it is desired selectively to write or erase.
Claim 16
Dependent Claim
38 words
An updatable write/erase information storage apparatus according to claim 13 wherein the insulating layer of the memory element is selected from the class of materials consisting of SiO2 and SiO and the polarizing material is an alkali metal.
Claim 17
Dependent Claim
25 words
An updatable write/erase information storage apparatus according to claim 14 wherein the alkali metal polarizing material is from the group consisting of sodium and lithium.
Claim 18
Dependent Claim
116 words
An updatable write/erase-fast read only information storage and retrievAl apparatus according to claim 13 further including means for increasing the penetrating power of the scanning electron beam produced by the scanning electron beam writing apparatus to cause it to penetrate through the insulator layer and interface to the adjacent space charge region of the semiconductor layer to thereby produce electron-hole carriers in the region, means for sweeping out the electron-hole carriers to produce output current pulses, and means for detecting the resulting output electron-hole carrier current pulses, and means for detecting the resulting output electron-hole carrier current pulses from the different discrete locations on the memory element as they are probed by the scanning electron beam.
Claim 19
Dependent Claim
42 words
An updatable write/erase-fast read only information storage and retrieval apparatus according to claim 16 wherein the insulating layer of the memory element is selected from the class of materials consisting of SiO2 and SiO and the polarizing material is an alkali metal.
Claim 20
Dependent Claim
29 words
An updatable write/erase-fast read only information storage and retrieval apparatus according to claim 17 wherein the alkali metal polarizing material is from the group consisting of sodium and lithium.
Claim 21
Dependent Claim
72 words
An updatable write/erase-fast read only information storage and retrieval apparatus according to claim 18 wherein the semiconductor layer is a p-type semiconductor and the positive space charge regions comprise depletion regions and enhanced positive polarity electron-hole current pulses are produced at those different discrete enhanced depletion region locations on the memory element where positive electric charges selectively were formed in the insulator in accordance with the intelligence recorded during the writing operation.
Claim 22
Dependent Claim
91 words
An updatable write/erase-fast read only information storage and retrieval apparatus according to claim 18 wherein the semiconductor layer is an n-type semiconductor and the enhanced space charge regions comprise accumulation regions, a polarizing reading potential which is negative in polarity is applied across the sandwich whereby the insulator layer is negative relative to the semiconductor layer, and reduced negative polarity electron-hole current pulses are produced at those different discrete enhanced accumulation region locations on the memory element where positive electric charges selectively were formed in the insulator during the writing operation.
Claim 23
Dependent Claim
104 words
A memory element for an updatable write/erase-fast read only information storage and retrieval system wherein data is stored in the form of electric charge patterns formed on the memory element, said memory element comprising, a conductive back layer, a semiconductor layer, an insulator layer enriched with an additive polarizing material and, a conductive front layer arranged in the order named in the form of a sandwich with the semiconductor layer and polarizing material enriched insulator layer forming an interface, whereby electric charges permanently stored in the insulating layer adjacent the interface produce an enhanced space charge region in the semiconductor layer adjacent the interface.
Claim 24
Dependent Claim
104 words
A memory element for an updatable write/erase-fast read only information storage and retrieval system wherein data is stored in the form of electric charge patterns formed on the memory element, said memory element comprising, a conductive back layer, a semiconductor layer, an insulator layer enriched with an additive polarizing material and, a conductive front layer arranged in the order named in the form of a sandwich with the semiconductor layer and polarizing material enriched insulator layer forming an interface, whereby electric charges permanently stored in the insulating layer adjacent the interface produce an enhanced space charge region in the semiconductor layer adjacent the interface.
Claim 25
Dependent Claim
33 words
A memory element according to claim 21 wherein, the conducitve front and back layers cover substantially the entire surface of the semiconductor and insulator layers opposite the surfaces thereof forming the insulator-semiconductor interface.
Claim 26
Dependent Claim
46 words
A memory element according to claim 22 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 27
Dependent Claim
55 words
A memory element according to claim 23 wherein, the conductive front layer and polarizing material enriched insulating layer have a combined thickness of about 1500 angstrom units (1500 A* ) with the thin coating of additive polarizing material disposed therebetween and the combined layers can Be penetrated by an electron beam of moderate energy level.
Claim 28
Dependent Claim
109 words
A memory element according to claim 24 wherein localized heating due to selective impingement of an electron beam into given areas of the polarizing material enriched insulator layer in the presence of a positive polarity polarizing electric field across the sandwich which biases the insulator layer positive with respect to the semiconductor layer produces positive mobile ions from the additive polarizing material which migrate to the interface and produce greatly enhanced stored positive electric charges upon subsequent cooling of the localized heated areas in the presence of the polarizing electric field and results in the production of localized enhanced space charge regions in the semiconductor layer adjacent the interface.
Claim 29
Dependent Claim
66 words
A memory element according to claim 25 wherein subsequent impingement of a reading electron beam into the enhanced space charge regions of the semiconductor layer produces electron-hole carriers which are separated and swept from the region by a built-in electric field in the semiconductor layer and results in the production of current pulses which are representative of the intelligence contained in the stored electric charge patterns.
Claim 30
Dependent Claim
32 words
A memory element according to claim 25 wherein the insulating layer is selected from the class of materials consisting of SiO2 and SiO and the additive polarizing material is an alkali metal.
Claim 31
Dependent Claim
23 words
A memory element according to claim 27 wherein the alkali metal additive polarizing material is from the group consisting of sodium and lithium.
Claim 32
Dependent Claim
66 words
A memory element according to claim 28 wherein subsequent impingement of a reading electron beam into the enhanced space charge regions of the semiconductor layer produces electron-hole carriers which are separted and swept from the region by a built-in electric field in the semiconductor layer and results in the production of current pulses which are representative of the intelligence contained in the stored electric charge patterns.
Claim 33
Dependent Claim
66 words
A memory element according to claim 29 wherein the semiconductor layer is a p-type semiconductor and the enhanced space charge regions comprise depletion regions, and results in the production of positive polarity electron-hole output current pulses at the different discrete enhanced depletion regions on the memory where positive electric charges selectively were formed in the insulator in accordance with the intelligence recorded on the memory element.
Claim 34
Dependent Claim
91 words
A memory element according to claim 29 wherein the semiconductor layer is a n-type semiconductor and the enhanced space charge regions comprise accumulation regions, a polarizing reading potential which is negative in polarity is applied across the sandwich whereby the insulator layer is negative relative to the semiconductor layer, and reduced negative polarity electron-hole output current pulses are produced at those different discrete enhanced accumulation region locations on the memory element where enhanced electric charges selectively were formed in the insulator in accordance with the intelligence recorded on the memory element.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-31 | 1976-05-01 | 1976-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-31 | 1980-05-01 | 1980-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-31 | 1984-05-01 | 1984-10-31 | $7700.00 | Window Closed / Lapsed |