Nonvolatile floating-gate memory devices, and process of fabrication
AssigneeSTMicroelectronics S.r.l.
InventorsCesare Clementi, Gabriella Ghidini, Mauro Alessandri
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Abstract
A process of fabricating a floating-gate memory device, the process including the steps of: forming a stack of superimposed layers including a floating gate region, a dielectric region, and a control gate region; and forming an insulating layer of oxynitride to the side of the floating gate region to completely seal the floating gate region outwards and improve the retention characteristics of the memory device. The insulating layer is formed during reoxidation of the sides of the floating gate region, after self-align etching the stack of layers and implanting the source/drain of the cell.
Claims15
A memory device comprising:
- a floating gate region having sidewalls;
- a dielectric region over said floating gate region;
- a control gate region over said dielectric region;
- and
- first oxynitride insulating layers on the sidewalls of said floating gate region.
A floating-gate memory device, comprising:
- an insulating layer on a semiconductor substrate;
- a first polysilicon layer positioned over said insulating layer;
- a dielectric material layer positioned over said first polysilicon layer;
- a second polysilicon layer positioned over said dielectric layer, wherein the first and second polysilicon layers and the dielectric layer are defined to form a gate stack;
- and
- first oxynitride sidewalls positioned on lateral walls of said second polysilicon layer.
Dependencies are inferred from the claim text.