US3838405A
Expired / Lapsed
US
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Non-volatile diode cross point memory array
Assignee: International Business Machines Corp
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Filing: 1973-10-03
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Granted: 1974-09-24
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Expires: 1993-10-03
Abstract
Abstract A dense memory array in which every cross point of two insulated orthogonal sets of lines define a non-volatile memory device is described. Each device utilizes voltage and storage charge to control breakdown characteristics of a PN junction. Basically, the array comprises insulated metallic word lines orthogonal to bit line diffusions in a semiconductor body. The insulation between the word lines and the bit lines has dual charge states and can store charges. Biasing of the word and bit lines causes charges to be injected into the insulation to affect the surface field of the body and thus change the breakdown voltage of the diffusion with respect to the semiconductor body. Both the read and write operations involve voltage breakdown of the PN junction between the diffused bit line and the body. During the write operation, an avalanche breakdown of the junction is caused to occur and charge carriers are injected into the overlying insulator. The charge carriers so injected remain localized in the insulator immediately above the junction and therefore do not disturb the information on adjacent bit lines. To erase, a voltage is applied to cause the injected carriers to be driven out of the insulation into the substrate. Reading consists of sensing the breakdown voltage of the selected bit.
Inventors
- 👤 P Arnett
- 👤 J Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:47
CPC Classifications
H; H10; H10D; H10D8/00; H10D8/812; G; G11; G11C; G11C16/00; G11C16/02; G11C16/04; G11C16/0466
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
103 words
A non-volatile memory storage device comprising, a body of semiconductor material, a diffusion in said body, defining a rectifying junction with said body, said junction having an initial breakdown voltage, a charge storage medium on the surface of said body and over said diffusion, an electrode disposed on said medium over said diffusion, means for biasing said diffusion with respect to said body to avalanche breakdown said junction and generate charge carriers, and means for biasing said electrode with respect to said body to accumulate charge carriers from said avalanche breakdown in said medium to alter the initial breakdown voltage of the junction.
Claim 2
Dependent Claim
103 words
A non-volatile memory storage device comprising, a body of semiconductor material, a diffusion in said body, defining a rectifying junction with said body, said junction having an initial breakdown voltage, a charge storage medium on the surface of said body and over said diffusion, an electrode disposed on said medium over said diffusion, means for biasing said diffusion with respect to said body to avalanche breakdown said junction and generate charge carriers, and means for biasing said electrode with respect to said body to accumulate charge carriers from said avalanche breakdown in said medium to alter the initial breakdown voltage of the junction.
Claim 3
Dependent Claim
20 words
The device of claim 1 wherein there is further provided means for determining the altered breakdown voltage of the junction.
Claim 4
Dependent Claim
35 words
The device of claim 2 wherein there is further provided means for biasing said electrode to remove said charge carriers from said medium and restore the breakdown voltage of the junction to its initial state.
Claim 5
Dependent Claim
21 words
The device of claim 3 wherein said body is silicon and said medium comprises layers of first and second dielectric materials.
Claim 6
Dependent Claim
37 words
The device of claim 4 wherein said first dielectric layer is silicon dioxide and in contact with said body and said second dielectric is silicon nitride and in contact with said first dielectric layer and said electrode.
Claim 7
Dependent Claim
36 words
The device of claim 5 wherein said charge storage medium comprises a layer of silicon dioxide between 20 and 100 angstroms in thickness and a layer of silicon nitride between 250 and 1,000 angstroms in thickness.
Claim 8
Dependent Claim
38 words
The device of claim 6 wherein there is further provided a second conductive electrode disposed on said medium adjacent said first electrode and over said diffusion, and means for biasing said second electrode with respect to said body.
Claim 9
Dependent Claim
24 words
The device of claim 1 wherein said biasing means for said diffusion comprises an address decoder and a driver circuit coupled to said diffusion.
Claim 10
Dependent Claim
26 words
The device of claim 2 wherein said means for determining the breakdown voltage of said junction comprises a voltage sensitive sense amplifier coupled to said diffusion.
Claim 11
Dependent Claim
24 words
The device of claim 1 wherein said means for biasing said electrode comprises an address decoder and a driver circuit coupled to said electrode.
Claim 12
Dependent Claim
234 words
A non-volatile memory storage array comprising, a body of semiconductor material, a series of adjacent parallel diffused regions in said body, each region defining a rectifying junction with said body, said junction having a initial breakdown voltage, a charge storage medium on the surface of said body over said regions, a series of spaced apart electrodes disposed on said medium over said regions, the intersection of each line with each region defining an active cell area, first voltage means for selectively biasing a selected one of said regions with respect to said body to avalanche breakdown the junction between the selected region and the body, and generate charge carriers, second voltage means for selectively biasing a selected one of said electrodes, with respect to said body to accumulate said charge carriers in said medium and under said selected electrode in the cell area defined by the intersection of the selected region and the selected electrode to alter the breakdown voltage of said junction in said cell area, decoupling means coupled between said means for biasing said diffusion to decouple said diffusion from said biasing means and leave said diffusion electrically floating, sensing means coupled to said regions for determining the breakdown voltage of the junction in said cell area, and third voltage means for biasing said selected electrode with respect to said body to remove charge carriers from said medium in said cell area.
Claim 13
Dependent Claim
234 words
A non-volatile memory storage array comprising, a body of semiconductor material, a series of adjacent parallel diffused regions in said body, each region defining a rectifying junction with said body, said junction having a initial breakdown voltage, a charge storage medium on the surface of said body over said regions, a series of spaced apart electrodes disposed on said medium over said regions, the intersection of each line with each region defining an active cell area, first voltage means for selectively biasing a selected one of said regions with respect to said body to avalanche breakdown the junction between the selected region and the body, and generate charge carriers, second voltage means for selectively biasing a selected one of said electrodes, with respect to said body to accumulate said charge carriers in said medium and under said selected electrode in the cell area defined by the intersection of the selected region and the selected electrode to alter the breakdown voltage of said junction in said cell area, decoupling means coupled between said means for biasing said diffusion to decouple said diffusion from said biasing means and leave said diffusion electrically floating, sensing means coupled to said regions for determining the breakdown voltage of the junction in said cell area, and third voltage means for biasing said selected electrode with respect to said body to remove charge carriers from said medium in said cell area.
Claim 14
Dependent Claim
130 words
A solid state storage device comprising a body of semiconductor material of a first conductivity type, a region in said body of opposite conductivity type defining a rectifying junction with said body, said junction extending to and intersecting the surface of said body, a charge storage medium on said surface over the intersection of said junction with said surface, conductive means overlying said medium and overlying the intersection of said junction with said surface, first voltage means for biasing said junction to cause an avalanche breakdown of said junction, second voltage means for biasing said conductive means to accumulate charge carriers from said avalanche breakdown of said junction in said medium to alter the breakdown voltage of said junction, and means for determining the altered breakdown voltage of said junction.
Claim 15
Dependent Claim
130 words
A solid state storage device comprising a body of semiconductor material of a first conductivity type, a region in said body of opposite conductivity type defining a rectifying junction with said body, said junction extending to and intersecting the surface of said body, a charge storage medium on said surface over the intersection of said junction with said surface, conductive means overlying said medium and overlying the intersection of said junction with said surface, first voltage means for biasing said junction to cause an avalanche breakdown of said junction, second voltage means for biasing said conductive means to accumulate charge carriers from said avalanche breakdown of said junction in said medium to alter the breakdown voltage of said junction, and means for determining the altered breakdown voltage of said junction.
References Cited (Backward Citations)
US3693003A
Cited
US3797000A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |