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US4313178A
Expired / Lapsed
US
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Analog solid state memory
Assignee: Massachusetts Institute of Technology
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Filing: 1979-09-28
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Granted: 1982-01-26
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Expires: 1999-09-28
Abstract
Abstract A solid state device capable of providing long-term storage of analog signals which in a particular embodiment utilizes a plurality of MNOS storage elements. An input analog signal is applied to a plurality of temporary storage means each associated with an MNOS storage element for temporarily storing a charge proportional to the amplitude of the portion of the input analog signal applied thereto. Storage control means are used to transfer the temporarily stored charges to the long-term MNOS storage elements so that controlled amounts of carrier charges are stored in the nitride layers thereof, such controlled amounts being substantially linearly proportional to the temporarily stored charges associated therewith. In a particular embodiment the input analog signal may be supplied via a surface acoustic wave (SAW) device and coupled to the MNOS device directly or it may be coupled to a charge-coupled device (CCD) and then coupled to the MNOS device.
Inventors
- 👤 Ernest R. Stern
- 👤 Richard W. Ralston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:14
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/69; H10D30/691; G; G11; G11C; G11C16/00; G11C16/02; G11C16/04; G11C16/0466; G11C27/00; G11C27/005; H10D84/00; H10D84/891; H10N; H10N39/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
207 words
An analog signal storage device comprising a plurality of first storage elements, each comprising a semiconductor substrate having at least two layers, at least one of said layers having a non-linear current vs. field conductivity characteristic and at least one other layer being capable of storing carrier charges therein; a plurality of second storage means, each associated with one of said plurality of first storage elements; means for applying an analog signal to said plurality of second storage means so that a charge is stored therein in each of said second storage means, the charge in each of said second storage means being proportional to the amplitude of a portion of said analog signal which is applied thereto; storage control means for transferring the stored charges in each of said second storage means to said first storage elements so that controlled amounts of carrier charges are stored in said at least one other layer of each of said first storage elements, the controlled amounts of carrier charges stored in each said first storage element being substantially linearly proportional to the charges in said second storage means associated therewith and being stored for a time period longer than the time period of storage in said second storage means.
Claim 2
Dependent Claim
207 words
An analog signal storage device comprising a plurality of first storage elements, each comprising a semiconductor substrate having at least two layers, at least one of said layers having a non-linear current vs. field conductivity characteristic and at least one other layer being capable of storing carrier charges therein; a plurality of second storage means, each associated with one of said plurality of first storage elements; means for applying an analog signal to said plurality of second storage means so that a charge is stored therein in each of said second storage means, the charge in each of said second storage means being proportional to the amplitude of a portion of said analog signal which is applied thereto; storage control means for transferring the stored charges in each of said second storage means to said first storage elements so that controlled amounts of carrier charges are stored in said at least one other layer of each of said first storage elements, the controlled amounts of carrier charges stored in each said first storage element being substantially linearly proportional to the charges in said second storage means associated therewith and being stored for a time period longer than the time period of storage in said second storage means.
Claim 3
Dependent Claim
43 words
An analog signal storage device in accordance with claim 1 wherein said semiconductor substrate has first and second dielectric layers, said first dielectric layer having said non-linear current vs. field conductivity characteristics and said second dielectric layer being capable of storing carrier charges.
Claim 4
Dependent Claim
41 words
An analog signal storage device in accordance with claim 2 wherein said plurality of first storage elements are metal-nitride-oxide-silicon storage elements wherein said first dielectric layer is a silicon oxide layer and said second dielectric layer is a silicon nitride layer.
Claim 5
Dependent Claim
134 words
A device in accordance with claim 2 or 3 and further including means for storing a pre-selected amount of carrier charges in said second dielectric layer of each of said first storage elements before said analog signal is applied to said second storage means; and said storage control means includes means for transferring the stored charges in each of said second storage means to its associated first storage element so as to controllably change the number of carrier charges which remain stored in said second dielectric layer of each of said first storage elements, the controlled change in the number of carrier charges which remain stored being linearly proportional to the stored charges in the associated second storage means, whereby an inverted replica of said analog signal is stored in said first storage elements.
Claim 6
Dependent Claim
160 words
A device in accordance with claim 4 and further wherein each of said second storage means further provides means for storing a selected amount of charge therein after said analog signal has been stored in said first storage elements; and each of said transferring means further provides means for transferring a sufficient portion of said stored selected amount of charge in said second storage means to the well of its associated first storage element to provide for equilibration of the stored selected amount of charge between each said second storage means and its associated first storage element, the charge remaining in each of said second storage means after said equilibration being proportional to the controlled amount of carrier charge which previously remained stored in said second dielectric layer of the first storage element associated therewith, whereby a replica of said analog signal is created in the second storage means without destroying the controlled charge stored in said first storage element.
Claim 7
Dependent Claim
44 words
A device in accordance with claim 5 and further including means for converting the said charges remaining in each of said second storage means into voltage signals so as to provide a voltage replica of the analog signal stored in said first storage elements.
Claim 8
Dependent Claim
36 words
A device in accordance with claim 4 wherein said preselected amount of carrier charges stored in said second dielectric layer before said analog signal is applied is substantially the saturated amount which can be so stored.
Claim 9
Dependent Claim
83 words
A device in accordance with claim 4 wherein the preselected amount of carrier charges stored in said second dielectric layer have a first polarity and further wherein the transfer of said stored charges in said second storage means by said transferring means causes a controlled amount of carrier charges of a second polarity to tunnel to said second dielectric layer through said first dielectric layer to produce a controlled net change in the carrier charges which remain stored in said second dielectric layer.
Claim 10
Independent Claim
86 words
A device in accordance with claims 5, 6 or 7 wherein the preselected amount of carrier charges stored in said second dielectric layer have a first polarity and further wherein the transfer of said stored charges in said second storage means by said transferring means causes a controlled amount of carrier charges of a second polarity to tunnel to said second dielectric layer through said first dielectric layer to produce a controlled net change in the carrier charges which remain stored in said second dielectric layer.
Claim 11
Independent Claim
23 words
A device in accordance with claims 1, 2, 3, 5, 6, 7 or 8 wherein said input analog signal is an optical signal.
Claim 12
Independent Claim
23 words
A device in accordance with claims 1, 2, 3, 5, 6, 7 or 8 wherein said input analog signal is an electrical signal.
Claim 13
Dependent Claim
16 words
A device in accordance with claim 4 wherein said input analog signal is an optical signal.
Claim 14
Dependent Claim
16 words
A device in accordance with claim 4 wherein said input analog signal is an electrical signal.
Claim 15
Dependent Claim
20 words
A device in accordance with claim 6 and further including means for converting said voltage replica to an optical image.
References Cited (Backward Citations)
US4070652A
Cited
US4101965A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-01-25 | 1985-07-27 | 1986-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-25 | 1989-07-27 | 1990-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-25 | 1993-07-27 | 1994-01-26 | $7700.00 | Window Closed / Lapsed |