US4196441A
Expired / Lapsed
US
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Semiconductor storage cell
Assignee: ITT Inc
•
Filing: 1978-05-05
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Granted: 1980-04-01
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Expires: 1998-05-05
Abstract
Abstract A programmable nonvolatile FET storage cell comprising crosswise to the ribbonlike source region as well as to the drain region a ribbonlike reading electrode and a separate ribbonlike writing electrode. Both electrodes are disposed upon a gate insulator layer into which a storage medium is embedded which is common to both electrodes.
Inventors
- 👤 Fritz G. Adam
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:42
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/60; H10D64/66; H10D64/68; H10D64/681; H10D64/683; G; G11; G11C; G11C16/00; G11C16/02; G11C16/04; G11C16/0408; G11C16/0441; H10D30/00; H10D30/60; H10D30/69; H10D64/691; H10D64/693; Y; Y10; Y10S; Y10S148/00; Y10S148/114
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
143 words
A semiconductor storage cell for nonvolatile electric charge storage, comprising: a ribbonlike source region and a ribbonlike drain region of one conductivity type which are formed in a plane surface of a semiconductor substrate of the other conductivity type, extending parallel to one another, and are interconnected via a channel region above which is disposed a gate insulator layer having an embedded storage medium therein for storing a charge below a gate electrode, that transversely to the source region and the drain region on the gate insulator layer with the embedded storage medium, a ribbonlike programming gate and a ribbonlike read gate are disposed above the channel region and parallel to one another, and that the storage medium below the two gates extends continuously over the entire width of both the read gate and the programming gate, thereby being common to both gates.
Claim 2
Dependent Claim
143 words
A semiconductor storage cell for nonvolatile electric charge storage, comprising: a ribbonlike source region and a ribbonlike drain region of one conductivity type which are formed in a plane surface of a semiconductor substrate of the other conductivity type, extending parallel to one another, and are interconnected via a channel region above which is disposed a gate insulator layer having an embedded storage medium therein for storing a charge below a gate electrode, that transversely to the source region and the drain region on the gate insulator layer with the embedded storage medium, a ribbonlike programming gate and a ribbonlike read gate are disposed above the channel region and parallel to one another, and that the storage medium below the two gates extends continuously over the entire width of both the read gate and the programming gate, thereby being common to both gates.
Claim 3
Dependent Claim
67 words
The semiconductor storage cell as claimed in claim 1, wherein between the source region and the drain region, the storage medium embedded in the gate insulator layer is disposed below the read gate and below the programming gate and extends over a central area of the channel region which area is separated from the source and drain regions by remaining partial areas of the gate insulating layer.
Claim 4
Dependent Claim
30 words
The semiconductor storage cell as claimed in claim 2, wherein the central area, the gate insulator layer with the embedded storage medium is thinner than in the remaining partial areas.
Claim 5
Dependent Claim
33 words
The semiconductor storage cell as claimed in claim 2 or 3, wherein the gate insulator layer covering the partial areas has a uniform thickness in the range between approximately 700 and 200 A.
Claim 6
Dependent Claim
58 words
The semiconductor storage cell as claimed in claim 2 or 3, wherein the storage medium is embedded bewteen two partial layers of the gate insulator layer, and that partial layer of the gate insulator layer which lies between the storage medium and the semiconductor surface has a uniform thickness in the range between approximately 30 and 300 A.
Claim 7
Dependent Claim
57 words
The semiconductor storage cell as claimed in claims 2 or 3, wherein the thickness of that partial layer of the gate insulator layer which lies between the storage medium and the programming gate is smaller than the thickness of that partial layer of the gate insulator layer which lies between the storage medium and the read gate.
Claim 8
Dependent Claim
39 words
The semiconductor storage cell as claimed in claim 6, wherein the partial layer of the gate insulator layer which lies between the storage medium and the programming gate has a thickness in the range between 30 and 400 A.
Claim 9
Dependent Claim
39 words
The semiconductor storage cell as claimed in claim 6, wherein the partial layer of the gate insulator layer which lies between the storage medium and the read gate has a thickness in the range between 400 and 2000 A.
Claim 10
Dependent Claim
38 words
The semiconductor storage cell as claimed in claims 1, 2 or 3, wherein the partial layer of the gate insulator layer which lies between the storage medium and the semiconductor surface is made of a uniform dielectric material.
Claim 11
Dependent Claim
48 words
The semiconductor storage cell as claimed in claim 9, wherein the partial layer of the gate insulator layer which lies between the storage medium and the semiconductor surface has a smaller dielectric constant that that of the partial layer laying between the storage medium and the programming gate.
Claim 12
Dependent Claim
72 words
The semiconductor storage cell as claimed in claim 10, wherein the partial layer of the gate insulator layer which lies between the storage medium and the semiconductor surface is made of SiO 2 , while that partial layer of the gate insulator layer which lies between the storage medium and the programming gate is made of Si 3 N 4 , Al 2 O 3 , or Ta 2 O 5 .
Claim 13
Dependent Claim
38 words
The semiconductor storage cell as claimed in claims 1, 2 or 3 wherein the section of the area of the storage medium which lies below the programming gate is larger than the section laying below the read gate.
Claim 14
Dependent Claim
38 words
The semiconductor storage cell as claimed in claim 12, wherein the ration of that area of the storage medium which lies below the programming gate to the area lying below the read gate is approximately 2:1 to 4:1.
Claim 15
Dependent Claim
43 words
The semiconductor storage cell as claimed in claims 1, 2 or 3 wherein the ration of that area of the storage medium which lies below the read gate to the area lying below the programming gate is approximately 1 or greater than 1.
Claim 16
Dependent Claim
20 words
The semiconductor storage cell as claimed in claim 14, wherein the ration of the areas lies between 1 and 3.
Claim 17
Dependent Claim
25 words
The semiconductor storage cell as claimed in claim 14 wherein all partial layers of the gate insulator layer are made of a chemically uniform material.
Claim 18
Dependent Claim
17 words
The semiconductor storage cell as claimed in claim 16, wherein the uniform material is SiO 2 .
Claim 19
Dependent Claim
71 words
The semiconductor storage cell as claimed in claim 14 wherein below the programming gate, the partial layer between the storage medium and the semiconductor surface is made of Si 3 N 4 , Al 2 O 3 or Ta 2 O 5 , while the partial layer between the storage medium and the programming gate as well as both partial layers below the read gate are made of SiO 2 .
Claim 20
Dependent Claim
54 words
The semiconductor storage cell as claimed in claim 14 wherein the partial layer of the gate insulator layer which lies between the storage medium and the programming gate is made of Si 3 N 4 , while the partial layer between the storage medium and the semiconductor surface is made of SiO 2 .
Claim 21
Dependent Claim
35 words
The semiconductor storage cell as claimed in claim 14 wherein the partial layer of the gate insulator layer which lies between the storage medium and the semiconductor surface is made of a chemically uniform material.
Claim 22
Dependent Claim
31 words
The semiconductor storage cell as claimed in any one of claims 1, 2 or 3, wherein the storage medium is a compact layer of a material with low electron work function.
Claim 23
Dependent Claim
39 words
The semiconductor storage cell as claimed in any one of claims 1, 2 or 3, wherein the storage medium is a layer of atomically dispersed electron traps whose average spacing lies in the range between 5 and 15 A.
Claim 24
Dependent Claim
43 words
The semiconductor storage cell as claimed in any one of claims 1, 2 or 3, wherein the storage medium is made from a material selected from the group consisting of n + -type polycrystalline silicon, germanium, aluminum arsenide, aluminum antimonide, and gallium arsenide.
Claim 25
Dependent Claim
26 words
The semiconductor storage cell as claimed in claim 23, wherein the programming gate is a layer of the same material as that of the storage medium.
Claim 26
Dependent Claim
27 words
The semiconductor storage cell as claimed in claim 23, wherein the read gate is a compact layer of the same material as that of the storage medium.
Claim 27
Dependent Claim
96 words
The semiconductor storage cell as claimed in claim 1, wherein the partial layer of the gate insulator layer which lies between the storage medium and the semiconductor surface is made of SiO 2 and has a thickness in the range between 100 and 200 A, that the partial layer between the read gate and the storage medium is made essentially of SiO 2 and has a thickness in the range between 600 and 133 A, and that the partial layer between the programming gate and the storage medium has a thickness between 50 and 300 A.
Claim 28
Dependent Claim
36 words
The semiconductor storage cell as claimed in claim 26, wherein the partial layer of the gate insulator layer which lies between the programming gate and the storage medium is made of Al 2 O 3 .
Claim 29
Dependent Claim
34 words
The semiconductor storage cell as claimed in claim 26 wherein the partial layer of the gate insulator layer which lies between the programming gate and the storage medium is made of SiO 2 .
Claim 30
Dependent Claim
36 words
The semiconductor storage cell as claimed in claim 26 wherein the partial layer of the gate insulator layer which lies between the programming gate and the storage medium is made of Si 3 N 4 .
Claim 31
Dependent Claim
46 words
The semiconductor storage cell as claimed in claims 27, 28 or 29, wherein the storage medium is made, from a material selected from the group consisting of n + -type polycrystalline silicon, n + -type aluminum antimonide, n + -type aluminum arsenide, aluminum, tungsten, or molybdenum.
Claim 32
Dependent Claim
42 words
The semiconductor storage cell as claimed in claim 30, wherein the programming gate is made from a material selected from the group consisting of n + -type polycrystalline silicon, aluminum, tungsten, n + -type aluminum arsenide, or n + -type aluminum antimonide.
Claim 33
Dependent Claim
48 words
The semiconductor storage cell as claimed in claim 31, wherein the read gate is made from a material selected from the group consisting of n + -type polycrystalline silicon, p + -type polycrystalline silicon, aluminum tungsten, molybdenum, n + -type aluminum arsenide, or n + -type aluminum antimonide.
Claim 34
Dependent Claim
48 words
The semiconductor storage cell as claimed in claim 12, wherein by applying a voltage pulse to the programming gate, the threshold voltage below the read gate is subjected to a change of that polarity which the voltage pulse has with respect to the potential of the semiconductor substrate.
Claim 35
Dependent Claim
53 words
The semiconductor storage cell as claimed in claim 14, wherein by applying a voltage pulse to the programming gate, the threshold voltage below the read gate is subjected to a change of that polarity which is opposite to the polarity of the voltage pulse with respect to the potential of the semiconductor substrate.
Claim 36
Dependent Claim
61 words
The semiconductor storage cell as claimed in claims 1, 2 or 3, wherein the storage medium is made from a material selected from the group consisting of metalls aluminum, gold titanium, magnesium, tantalum, tungsten, molybdenum, thallium molybdenum, thallium either in the form of a compact metallic layer or in the form of a layer atomically dispersed in the gate insulator layer.
References Cited (Backward Citations)
US3836894A
Cited
US4063267A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-04-01 | 1983-10-01 | 1984-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-01 | 1987-10-01 | 1988-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-01 | 1991-10-01 | 1992-04-01 | $7700.00 | Window Closed / Lapsed |