Patent US3825946A successfully refreshed from Google Patents.
US3825946A
Expired / Lapsed
US
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Electrically alterable floating gate device and method for altering same
Assignee: Intel Corp
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Filing: 1973-10-19
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Granted: 1974-07-23
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Expires: 1993-10-19
Abstract
Abstract A field effect device having a floating gate which can be charged or discharged electrically is disclosed. A pair of spaced apart regions in a substrate define a channel above which a floating gate is disposed and insulated from the channel. The regions have a conductivity type opposite to the substrate. A second gate is disposed above and insulated from the floating gate. The floating gate may be charged electrically by producing an avalanche breakdown at the junction formed by one of the spaced apart regions and the substrate causing the passage of electrons through the insulation onto the floating gate. The floating gate may be discharged by the application of a voltage to the second gate relative to the spaced apart regions and substrate causing the passage of electrons from the floating gate through the insulation onto the second gate.
Inventors
- 👤 Bentchkowsky D Frohman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:03
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/68; H10D30/681; H10D30/684; H10D30/686; H10P; H10P95/00
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
206 words
A storage device into which information may be electrically placed and electrically removed comprising: a substrate of a first conductivity type; a pair of spaced apart regions in said substrate and of opposite conductivity type to said substrate, said regions defining a channel area in said substrate; a floating gate disposed above said channel area and insulated from said channel area and having a portion extending beyond said channel area of said spaced apart regions; a second gate disposed above said floating gate and insulated from said floating gate; a third gate disposed above said floating gate and insulated from said floating gate and said second gate, said third gate located above said extended portion of said floating gate in an area beyond the area of said spaced apart region, said second and third gates adapted to conductively enable a discharge from said floating gate to take place; and electrical means coupled to at least one of said spaced apart regions for causing an avalanche injection from at least one of the junctions defined by one of said spaced apart regions on said substrate to said floating gate for charging said floating gate; whereby electrical charge may be placed on and removed from said floating gate.
Claim 2
Dependent Claim
206 words
A storage device into which information may be electrically placed and electrically removed comprising: a substrate of a first conductivity type; a pair of spaced apart regions in said substrate and of opposite conductivity type to said substrate, said regions defining a channel area in said substrate; a floating gate disposed above said channel area and insulated from said channel area and having a portion extending beyond said channel area of said spaced apart regions; a second gate disposed above said floating gate and insulated from said floating gate; a third gate disposed above said floating gate and insulated from said floating gate and said second gate, said third gate located above said extended portion of said floating gate in an area beyond the area of said spaced apart region, said second and third gates adapted to conductively enable a discharge from said floating gate to take place; and electrical means coupled to at least one of said spaced apart regions for causing an avalanche injection from at least one of the junctions defined by one of said spaced apart regions on said substrate to said floating gate for charging said floating gate; whereby electrical charge may be placed on and removed from said floating gate.
Claim 3
Dependent Claim
26 words
The device defined in claim 1 wherein said substrate is n-type silicon, said spaced apart regions are p-type silicon and said floating gate is p-type silicon.
Claim 4
Dependent Claim
34 words
The device defined in claim 2 wherein silicon oxide insulation is disposed between said floating gate and substrate, between said floating gate and second gate and between said second gate and said third gate.
Claim 5
Dependent Claim
16 words
The device defined in claim 3 wherein said floating gate is completely surrounded by silicon oxide.
Claim 6
Dependent Claim
126 words
A storage device into which information may be electrically placed and electrically removed comprising: a substrate of a first conductivity type; a pair of spaced apart regions in said substrate of opposite conductivity type to said substrate, said regions defining a channel; a floating gate disposed above said channel and insulated from said channel; a second gate disposed above said floating gate and insulated from said floating gate for discharging said floating gage; electrical means coupled to at least one of said spaced apart regions for causing an avalanche injection from the junction defined by one of said spaced apart regions and said substrate to said floating gate for charging said floating gate; whereby electrical charge may be placed on and removed from said floating gate.
Claim 7
Dependent Claim
126 words
A storage device into which information may be electrically placed and electrically removed comprising: a substrate of a first conductivity type; a pair of spaced apart regions in said substrate of opposite conductivity type to said substrate, said regions defining a channel; a floating gate disposed above said channel and insulated from said channel; a second gate disposed above said floating gate and insulated from said floating gate for discharging said floating gage; electrical means coupled to at least one of said spaced apart regions for causing an avalanche injection from the junction defined by one of said spaced apart regions and said substrate to said floating gate for charging said floating gate; whereby electrical charge may be placed on and removed from said floating gate.
Claim 8
Dependent Claim
13 words
The device defined in claim 5 wherein said floating gate comprises p-type silicon.
Claim 9
Dependent Claim
34 words
The device defined in claim 5 wherein said substrate is insulated from said floating gate by silicon oxide insulation and wherein said second gate is insulated from said floating gate by silicon oxide insulation.
Claim 10
Dependent Claim
146 words
An electrically programmable memory device comprising: a substrate of a first conductivity type; a pair of spaced apart regions of opposite conductivity type to said first conductivity type disposed in said substrate; a floating gate disposed between said spaced apart regions; a second gate disposed above said floating gage for removing a charge from said floating gate; a third gate disposed above said floating gate and insulated from said floating gate and said second gate, said second and third gate adapted to cooperatively enable discharge to take place from said floating gate; and electrical means coupled to at least one of said spaced apart regions for causing an avalanche injection from the junction defined by one of said spaced apart regions and said substrate to said floating gate for charging said floating gate; whereby electrical charge may be placed on and removed from said floating gate.
Claim 11
Dependent Claim
146 words
An electrically programmable memory device comprising: a substrate of a first conductivity type; a pair of spaced apart regions of opposite conductivity type to said first conductivity type disposed in said substrate; a floating gate disposed between said spaced apart regions; a second gate disposed above said floating gage for removing a charge from said floating gate; a third gate disposed above said floating gate and insulated from said floating gate and said second gate, said second and third gate adapted to cooperatively enable discharge to take place from said floating gate; and electrical means coupled to at least one of said spaced apart regions for causing an avalanche injection from the junction defined by one of said spaced apart regions and said substrate to said floating gate for charging said floating gate; whereby electrical charge may be placed on and removed from said floating gate.
Claim 12
Dependent Claim
12 words
The device defined in claim 8 wherein said floating gate comprises silicon.
Claim 13
Dependent Claim
38 words
The device defined in claim 9 wherein said floating gate is insulated from said substrate by silicon oxide insulation and wherein said third gate is insulated from said floating gate and said second gate by silicon oxide insulation.
Claim 14
Dependent Claim
30 words
The device defined in claim 8 wherein said floating gate extends beyond a channel defined by said spaced apart regions and said second gate is laterally displaced from said channel.
Claim 15
Dependent Claim
147 words
A storage device into which information may be electrically placed and electrically removed comprising: a substrate of a first conductivity type; a pair of spaced apart regions in said substrate of opposite conductivity type to said substrate, said regions defining a channel; a floating gate disposed above said channel and insulated from said channel by insulation of at least approximately 1,000 A thick; a second gate disposed above said floating gate and insulated from said floating gate, said second gate adapted to cooperatively enable a discharge to take place from said floating gate; and electrical means coupled to at least one of said spaced apart regions for causing an avalanche injection from the junction defined by one of said spaced apart regions and said substrate to said floating gate whereby charging said floating gate; whereby electrical charge may be placed on and removed from said floating gate.
Claim 16
Dependent Claim
147 words
A storage device into which information may be electrically placed and electrically removed comprising: a substrate of a first conductivity type; a pair of spaced apart regions in said substrate of opposite conductivity type to said substrate, said regions defining a channel; a floating gate disposed above said channel and insulated from said channel by insulation of at least approximately 1,000 A thick; a second gate disposed above said floating gate and insulated from said floating gate, said second gate adapted to cooperatively enable a discharge to take place from said floating gate; and electrical means coupled to at least one of said spaced apart regions for causing an avalanche injection from the junction defined by one of said spaced apart regions and said substrate to said floating gate whereby charging said floating gate; whereby electrical charge may be placed on and removed from said floating gate.
Claim 17
Dependent Claim
43 words
The device defined in claim 12 including a third gate disposed above said floating gate and insulated from said floating gate and said second gate, said second and third gate adapted to cooperatively enable a discharge to take place from said floating gate.
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) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |