FinFET split gate EEPROM structure and method of its fabrication
First Claim
1. A finFET split gate EEPROM structure, comprising:
- an elongated, elevated semiconductor fin having a source and a drain formed therein to define a channel therebetween;
a control gate structure straddling the fin and overlying a first portion of the channel, the control gate structure comprising a tunnel layer on the fin, a floating electrode on the tunnel layer, a first insulative stratum over the floating electrode, and a first conductive stratum on the first insulative stratum; and
a select gate structure straddling the fin and overlying a second portion of the channel, the select gate structure comprising a second insulating stratum on the fin, and a second conductive stratum on the second insulative stratum, the second conductive stratum and the first conductive stratum being contiguous portions of a continuous conductive layer.
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Accused Products
Abstract
A FinFET split gate EEPROM structure includes a semiconductor substrate and an elongated semiconductor fin extending above the substrate. A control gate straddles the fin, the fin'"'"'s sides and a first drain-proximate portion of a channel between a source and drain in the fin. The control gate includes a tunnel layer and a floating electrode over which are a first insulative stratum and a first conductive stratum. A select gate straddles the fin and its sides and a second, source-promixate portion of the channel. The select gate includes a second insulative stratum and a second conductive stratum. The insulative strata are portions of a continuous insulative layer covering the substrate and the fin. The conductive strata are electrically continuous portions of a continuous conductive layer formed on the insulative layer.
253 Citations
20 Claims
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1. A finFET split gate EEPROM structure, comprising:
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an elongated, elevated semiconductor fin having a source and a drain formed therein to define a channel therebetween;
a control gate structure straddling the fin and overlying a first portion of the channel, the control gate structure comprising a tunnel layer on the fin, a floating electrode on the tunnel layer, a first insulative stratum over the floating electrode, and a first conductive stratum on the first insulative stratum; and
a select gate structure straddling the fin and overlying a second portion of the channel, the select gate structure comprising a second insulating stratum on the fin, and a second conductive stratum on the second insulative stratum, the second conductive stratum and the first conductive stratum being contiguous portions of a continuous conductive layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A semiconductor structure, comprising:
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a generally planar, thin semiconductor member having opposed major surfaces and a source and a drain formed therein to define therebetween a channel that is generally parallel to the major surfaces;
a control gate structure located on the major surfaces of the member so as to overlie both sides of a first portion of the channel, the control gate structure comprising a tunnel layer on each major surface, a floating electrode on each tunnel layer, a first insulative stratum over each floating electrode, and a first conductive stratum on each first insulative stratum; and
a select gate structure located on the major surfaces of the member so as to overlie a second portion of the channel, the select gate structure comprising a second insulating stratum on each major surface, and a second conductive stratum on each second insulative stratum, wherein the second conductive stratum and the first conductive stratum are contiguous portions of a continuous conductive layer. - View Dependent Claims (13, 14, 15, 16)
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17. A method of fabricating a split gate FinFET EEPROM on a planar semiconductor substrate, which comprises:
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(a) covering the substrate with an insulative film;
(b) forming on the insulative film an elevated, extended semiconductor fin having opposed major surfaces that are not parallel with the plane of the substrate;
(c) forming a substantially “
U”
-shaped tunnel layer on the fin'"'"'s major surfaces and over the top of the fin;
(d) forming a substantially “
U”
-shaped floating electrode on the tunnel layer;
(e) forming a separated source and drain in the fin to define therebetween a channel that is parallel to the fin'"'"'s major surfaces so that the tunnel layer overlies a first portion of the channel (f) forming an outer insulative layer over the floating electrode, on the sides of the floating electrode and the tunnel layer, and on portions of the major surfaces and top of the fin not covered by the tunnel layer; and
(g) forming a continuous outer conductive layer on the insulative layer over both the first channel portion and over a second channel portion that is nearer to the source than to the drain. - View Dependent Claims (18, 19, 20)
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Specification