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US5721441A Expired / Lapsed US ⏱️ 0.0 years remaining

High density flash memory cell and method of forming a line of floating gate transistors

Assignee: Micron Technology Inc
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Filing: 1996-11-12
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Granted: 1998-02-24
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Expires: 2016-11-12
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Abstract

Abstract A method of forming a line for floating gate transistors is described and which includes, providing a substrate having a plurality of discrete field oxide regions, and intervening active area regions therebetween; forming a first alternating series of floating gates over a first alternating series of active area regions; forming a second alternating series of floating gates over a second alternating series of active area regions, the second series of floating gates disposed in spaced, overlapping and partial covering relation relative to the first alternating series of floating gates; forming a layer of dielectric material over the first and second series of floating gates; and forming a control gate layer of electrically conductive material over the layer of dielectric material. The present invention further relates to a memory chip, and die having a line of floating gate transistors formed from the same method.

Inventors

  • 👤 Roger R. Lee

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 10:09
CPC Classifications
H; H10; H10B; H10B41/00; H10B41/30; H10B69/00

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 175 words
A line of floating gate transistors, comprising: a substrate having a plurality of discrete field oxide regions disposed in spaced relation relative to one another, and active area regions therebetween; a plurality of first floating gates individually disposed over alternating active area regions, and covering more than one-half of the immediately adjacent field oxide regions, over which they lie the individual floating gates each having sidewalls; a plurality of second floating gates individually disposed over an alternating series of active area regions and the adjoining field oxide regions, the second floating gates disposed in spaced relation relative to the first floating gates, and at least a portion of the second floating gates disposed in overlapping, spaced relation, relative to the first floating gates; a layer of electrically insulative material disposed in covering relation relative to the sidewalls of the first floating gates; a layer of dielectric material disposed in covering relation relative to the first and second floating gates; and a control gate layer disposed in covering relation relative to the layer of dielectric material.
Claim 2
Dependent Claim 175 words
A line of floating gate transistors, comprising: a substrate having a plurality of discrete field oxide regions disposed in spaced relation relative to one another, and active area regions therebetween; a plurality of first floating gates individually disposed over alternating active area regions, and covering more than one-half of the immediately adjacent field oxide regions, over which they lie the individual floating gates each having sidewalls; a plurality of second floating gates individually disposed over an alternating series of active area regions and the adjoining field oxide regions, the second floating gates disposed in spaced relation relative to the first floating gates, and at least a portion of the second floating gates disposed in overlapping, spaced relation, relative to the first floating gates; a layer of electrically insulative material disposed in covering relation relative to the sidewalls of the first floating gates; a layer of dielectric material disposed in covering relation relative to the first and second floating gates; and a control gate layer disposed in covering relation relative to the layer of dielectric material.

References Cited (Backward Citations)

US5107313A Cited
US5610419A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-02-23 2001-08-25 2002-02-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-02-23 2005-08-25 2006-02-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-02-23 2009-08-25 2010-02-24 $7700.00 Window Closed / Lapsed

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