Electrically programmable memory cell
AssigneeSGS-Thomson Microelectronics S.A.
InventorsConstantin Papadas, Bernard Guillaumot
Life of this patent
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Abstract
An electrically programmable cell comprises a substrate of the first conductivity type having a channel region, a control gate on a first insulating layer above the channel region, a source region and a drain region of a second conductivity type, on both sides of the channel region, at least the drain region including a low-doped region adjacent to the channel, a floating gate on a second insulating layer above at least a portion of said low-doped region. The thickness of the second insulating layer is lower than the thickness of the first insulating layer and is low enough for having charge transfers through tunnel effect.
Claims17
Electrically programmable cell comprising:
- a substrate of a first conductivity type, having a channel region having a first side and a second side;
- a control gate located on a first insulating layer above the channel region;
- a drain region of a second conductivity type located on the substrate adjacent to the first side of the channel region, the drain region having a low-doped region adjacent to the channel region;
- a source region of the second conductivity type located on the substrate adjacent to the second side of the channel region;
- an insulated floating gate located on a second insulating layer above a portion of the drain region, the insulated floating gate being disposed such that it does not extend over the channel region.
An electrically programmable cell comprising:
- a substrate of a first conductivity type having a semiconductor face including a channel region, the channel region having first and second sides and an upper surface;
- a first insulating layer disposed over the channel region;
- a control gate disposed over the first insulating layer and disposed over the upper surface of the channel region of the semiconductor face;
- a drain region of a second conductivity type disposed over the semiconductor face adjacent the first side of the channel region;
- a source region of the second conductivity type disposed over the semiconductor face adjacent to the second side of the channel region;
- an insulated floating gate disposed over the semiconductor face such that the insulated floating gate encircles the control gate;
- and
- a second insulating layer disposed between the drain region and the insulated floating gate.
Dependencies are inferred from the claim text.