US4435785A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Unipolar voltage non-volatile JRAM cell
Assignee: Texas Instruments Inc
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Filing: 1981-06-02
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Granted: 1984-03-06
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Expires: 2001-06-02
Abstract
Abstract A non-volatile JRAM cell is constructed to require only positive voltage for programming and erasing of data in the cell. The "well" region of the cell JFET device may be implanted with an impurity concentration that will permit lower breakdown voltage or the non-volatile gate may overlap the JFET gate sufficiently to be able to have the same effect, or some combination of both may be used. This allows the cell to be erased using voltages of one polarity.
Inventors
- 👤 Richard A. Chapman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:47
CPC Classifications
G; G11; G11C; G11C16/00; G11C16/02; G11C16/04; G11C16/0466; G11C11/00; G11C11/21; G11C11/34; G11C11/39; H; H10; H10D; H10D30/00; H10D30/80; H10D30/83; H10D84/00; H10D84/80; H10D84/811; H10D84/813; H10D84/82
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
56 words
A non-volatile data storage cell having a P-channel JFET as the addressing element for the non-volatile storage element of said cell, said P-channel JFET having a source region of a higher level of impurity concentration for changing voltage breakdown threshold, wherein writing and erasing data in said cell is accomplished by voltages of the same polarity.
Claim 2
Dependent Claim
56 words
A non-volatile data storage cell having a P-channel JFET as the addressing element for the non-volatile storage element of said cell, said P-channel JFET having a source region of a higher level of impurity concentration for changing voltage breakdown threshold, wherein writing and erasing data in said cell is accomplished by voltages of the same polarity.
Claim 3
Dependent Claim
14 words
A cell as in claim 1, wherein said polarity of voltage is positive (+).
Claim 4
Dependent Claim
14 words
A cell as in claim 1, wherein said polarity of voltage is negative (-).
Claim 5
Dependent Claim
21 words
A random-access memory array of cells as in claim 1, wherein peripheral devices of said array are fabricated in NMOS technology.
Claim 6
Dependent Claim
160 words
A non-volatile data storage cell comprising: a semiconductor substrate of one conductivity type; a first region of conductivity opposite that of the substrate, extending to the surface of said substrate, wherein said first region surrounds an enclosed region of said substrate, said enclosed region of substrate having a higher level of impurity concentration of the same conductivity type as said substrate for changing the breakdown voltage between said substrate and said first region of opposite conductivity; an insulating layer covering the surface of said substrate, said first region of opposite conductivity, and said enclosed region of substrate; a multidielectric structure overlying said enclosed substrate region and recessed into said insulating layer such that a reduced thickness of said insulating layer is present between said dielectric structure and said enclosed substrate region, than is present between said substrate and subsequent structure parts; a conductor arranged on the surface of said insulating layer to be in contact with said multilayer dielectric structure.
Claim 7
Dependent Claim
160 words
A non-volatile data storage cell comprising: a semiconductor substrate of one conductivity type; a first region of conductivity opposite that of the substrate, extending to the surface of said substrate, wherein said first region surrounds an enclosed region of said substrate, said enclosed region of substrate having a higher level of impurity concentration of the same conductivity type as said substrate for changing the breakdown voltage between said substrate and said first region of opposite conductivity; an insulating layer covering the surface of said substrate, said first region of opposite conductivity, and said enclosed region of substrate; a multidielectric structure overlying said enclosed substrate region and recessed into said insulating layer such that a reduced thickness of said insulating layer is present between said dielectric structure and said enclosed substrate region, than is present between said substrate and subsequent structure parts; a conductor arranged on the surface of said insulating layer to be in contact with said multilayer dielectric structure.
Claim 8
Dependent Claim
12 words
A cell as in claim 5, wherein said semiconductor substrate is P-type.
Claim 9
Dependent Claim
37 words
A cell as in claim 5, wherein said multilayer dielectric structure comprises: a layer of silicon dioxide upon said nitride layer; a layer of titanium dioxide of a form known as rutile upon said silicon dioxide layer.
Claim 10
Dependent Claim
40 words
A cell as in claim 5, wherein said multi-layer dielectric c structure comprises: a layer of silicon nitride upon said insulating layer and overlying said enclosed region of substrate; and a layer of silicon oxide upon said layer of nitride.
Claim 11
Dependent Claim
176 words
A non-volatile data storage cell comprising: a semiconductor substrate of one conductivity type; a first region of conductivity opposite that of the substrate, wherein said first region surrounds an enclosed region of said substrate, said enclosed region of substrate having a higher level of impurity concentration of the same conductivity type as said substrate and an overlap of the multidielectric structure extending over the junction of said first region of opposite conductivity and said enclosed substrate region for changing the breakdown voltage between said substrate and said first region of opposite conductivity; an insulating layer covering the surface of said substrate, said first region of opposite conductivity, and said enclosed region of substrate; a multidielectric structure overlying said enclosed substrate region and recessed into said insulating layer such that a reduced thickness of said insulating layer is present between said dielectric structure and said enclosed substrate region, than is present between said substrate and subsequent structure parts; a conductor, arranged on the surface of said insulating layer to be in contact with said multilayer dielectric structure.
Claim 12
Dependent Claim
176 words
A non-volatile data storage cell comprising: a semiconductor substrate of one conductivity type; a first region of conductivity opposite that of the substrate, wherein said first region surrounds an enclosed region of said substrate, said enclosed region of substrate having a higher level of impurity concentration of the same conductivity type as said substrate and an overlap of the multidielectric structure extending over the junction of said first region of opposite conductivity and said enclosed substrate region for changing the breakdown voltage between said substrate and said first region of opposite conductivity; an insulating layer covering the surface of said substrate, said first region of opposite conductivity, and said enclosed region of substrate; a multidielectric structure overlying said enclosed substrate region and recessed into said insulating layer such that a reduced thickness of said insulating layer is present between said dielectric structure and said enclosed substrate region, than is present between said substrate and subsequent structure parts; a conductor, arranged on the surface of said insulating layer to be in contact with said multilayer dielectric structure.
References Cited (Backward Citations)
US4156939A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-06 | 1987-09-05 | 1988-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-06 | 1991-09-05 | 1992-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-06 | 1995-09-05 | 1996-03-06 | $7700.00 | Window Closed / Lapsed |