Flash memory cell with UV protective layer
View Patent ↗A method of protecting a charge trapping dielectric flash memory cell from UV-induced charging, including fabricating a charge trapping dielectric flash memory cell in a semiconductor device; depositing and planarizing an interlevel dielectric layer over the charge trapping dielectric flash memory cell and depositing over the planarized interlevel dielectric layer at least one UV-protective layer, the UV-protective layer including a substantially UV-opaque material.
1. A semiconductor device comprising:
a charge trapping dielectric flash memory cell;
at least one UV-protective layer,
the UV-protective layer comprises a substantially UV-opaque material; and
an interlevel dielectric layer including a portion of a sacrificial layer in a thickness variation of the interlevel dielectric layer,
the portion of the sacrificial layer reducing the thickness variation in the interlevel dielectric layer.
2. The device of claim 1 , wherein the portion of the sacrificial layer comprises one or more of a silicon nitride, a silicon oxynitride, a silicon carbide, a silicon carbide-nitride, a silicon-rich nitride, silicon-rich oxide, silicon-rich carbide, silicon-rich carbide-nitride, carbon polymers, low-k materials, graded films or thin metal films.
3. The device of claim 1 , wherein the UV-protective layer is a contact cap layer disposed over the charge trapping dielectric flash memory cell.
4. The device of claim 1 , wherein the UV-protective layer protects the charge trapping dielectric flash memory cell from damage resulting from UV exposure during Back End Of Line (BEOL) processing in fabrication of the charge trapping dielectric flash memory device.
5. The device of claim 1 , wherein the UV-opaque material comprises one or more of silicon-rich nitride, silicon-rich oxide, silicon-rich carbide, silicon-rich SiCN, carbon polymers, low-k materials, graded films and thin metal films.
6. The device of claim 1 , further comprising;
at least one additional UV-protective layer,
the at least one additional UV-protective layer comprising at least a sub-layer of a UV-opaque material.
7. The device of claim 6 , wherein the at least one additional UV-protective layer is a component of one or more of an interlayer dielectric layer 1 , interlayer dielectric layer 2 , or a top oxide layer.
8. The device of claim 7 , further comprising;
second and third UV-protective layers,
wherein the second and third UV-protective layers each comprise at least a sublayer of a UV-opaque material.
9. A semiconductor device comprising:
a charge trapping dielectric flash memory cell;
an interlevel dielectric layer including at least one portion of a sacrificial layer in a thickness variation of a planarized interlevel dielectric layer;
a UV-protective contact cap layer disposed over the planarized interlevel dielectric layer,
the UV-protective contact cap layer comprising a substantially UV-opaque material; and
at least one additional UV-protective layer,
the at least one additional UV-protective layer comprising at least a sublayer of a UV-opaque material,
wherein each UV-opaque material comprises one or more of silicon-rich nitride, silicon-rich silicon oxide, silicon-rich carbide, silicon-rich SiCN, carbon polymers, low-k materials, graded films and thin metal films, and
wherein the UV-protective layers protect the charge trapping dielectric flash memory cell from damage resulting from UV exposure during BEOL processing in fabrication of the charge trapping dielectric flash memory device.