US5028979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Table cloth matrix of EPROM memory cells with buried junctions, individually accessible by a traditional decoder
Assignee: STMicroelectronics SRL
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Filing: 1990-03-05
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Granted: 1991-07-02
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Expires: 2010-03-05
Abstract
Abstract The table cloth matrix comprises a semiconductor substrate, wherein there are contained in deep layers, under strips of field oxide, source lines and drain lines parallel to one another, areas of floating gate connecting said source lines and drain lines and control gate lines, parallel to one another and perpendicular to said source lines and drain lines, in a condition superimposed over said floating gate areas. Each source line is alternated with two drain lines separated by an insulation zone, so that each drain line is associated with a single row of matrix cells.
Inventors
- 👤 Stefano Mazzali
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:55
CPC Classifications
G; G11; G11C; G11C16/00; G11C16/02; G11C16/04; G11C16/0408; G11C16/0416; H; H10; H10B; H10B69/00; H10D; H10D30/00; H10D30/60; H10D30/68; H10D30/681; H10D30/684; H10D30/685
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
118 words
A matrix of EPROM memory cells, comprising a semiconductor substrate, a plurality of first and second parallel strips of field oxide formed on the substrate, parallel source lines arranged in buried layers of the substrate under said first strips of field oxide, pairs of parallel drain lines arranged in buried layers of the substrate under each of said second strips of field oxide, floating gases interposed between said source lines and said drain lines and provided with lateral extensions superimposed over lateral portions of said first and second strips of field oxide, and control gate lines parallel to one another and perpendicular to said source and drain lines and superimposed on and aligned with said floating gate areas.
Claim 2
Dependent Claim
118 words
A matrix of EPROM memory cells, comprising a semiconductor substrate, a plurality of first and second parallel strips of field oxide formed on the substrate, parallel source lines arranged in buried layers of the substrate under said first strips of field oxide, pairs of parallel drain lines arranged in buried layers of the substrate under each of said second strips of field oxide, floating gases interposed between said source lines and said drain lines and provided with lateral extensions superimposed over lateral portions of said first and second strips of field oxide, and control gate lines parallel to one another and perpendicular to said source and drain lines and superimposed on and aligned with said floating gate areas.
Claim 3
Dependent Claim
22 words
A matrix according to claim 1, wherein said first strips of field oxide are narrower than said second strips of field oxide.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-01 | 1994-12-31 | 1995-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-01 | 1998-12-31 | 1999-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-01 | 2002-12-31 | 2003-07-02 | $7700.00 | Window Closed / Lapsed |