Non-Volatile memory with silicided bit line contacts
View Patent ↗An approach to use silicided bit line contacts that do not short to the underlying substrate in memory devices. The approach provides for silicide formation in the bit line contact area, using a process that benefits from being self-aligned to the oxide-nitride-oxide (ONO) nitride edges. A further benefit of the approach is that the bit line contact implant and rapid temperature anneal process can be eliminated. This approach is applicable to embedded flash, integrating high density devices and advanced logic processes.
1. A memory array having a plurality of charge trapping dielectric memory devices, comprising:
a substrate having a first bit line and a second bit line formed therein and a body region interposed between the first and the second bit lines;
a first dielectric layer disposed on the body region;
a dielectric charge trapping layer disposed on the first dielectric layer; and
a second dielectric layer disposed on the dielectric charge trapping layer, the first dielectric layer and the dielectric charge trapping layer extending beyond the second dielectric layer in a direction parallel to a top surface of the substrate.
2. The memory array of claim 1 , wherein the first dielectric layer and the dielectric charge trapping layer extend beyond the body region and over the first bit line and the second bit line.
3. The memory array of claim 1 , wherein the first dielectric layer comprises silicon dioxide.
4. The memory array of claim 1 , wherein the dielectric charge trapping layer comprises silicon-rich nitride (SiRN).
5. The memory array of claim 1 , wherein the second dielectric layer comprises silicon oxide.
6. The memory array of claim 1 , further comprising:
a bit line contact region disposed above each bit line, the bit line contact region including a metalized portion coupled to the respective bit line.
7. The memory array of claim 1 , wherein the metallized portion comprises a silicide.
8. The memory array of claim 7 , wherein the silicide comprises at least one of titanium silicide, cobalt silicide and nickel silicide.
9. A charge trapping dielectric memory device, comprising:
a first dielectric layer disposed on a substrate;
a dielectric charge trapping layer disposed on the first dielectric layer; and
a second dielectric layer disposed on the dielectric charge trapping layer, the first dielectric layer and the dielectric charge trapping layer extending beyond the second dielectric layer in a direction parallel to a top surface of the substrate.
10. The charge trapping dielectric memory device of claim 9 , wherein the first dielectric layer comprises silicon dioxide.
11. The charge trapping dielectric memory device of claim 9 , wherein the dielectric charge trapping layer comprises silicon-rich nitride (SiRN).
12. The charge trapping dielectric memory device of claim 9 , wherein the second dielectric layer comprises silicon oxide.
13. The charge trapping dielectric memory device of claim 9 , further comprising:
a bit line contact region disposed above each bit line, the bit line contact region including a metalized portion coupled to the respective bit line.
14. The charge trapping dielectric memory device of claim 13 , wherein the metallized portion comprises a silicide.
15. The charge trapping dielectric memory device of claim 14 , wherein the silicide comprises at least one of titanium silicide, cobalt silicide and nickel silicide.