Reprogrammable metal-to-metal antifuse employing carbon-containing antifuse material
View Patent ↗A reprogrammable metal-to-metal antifuse is disposed between two metal interconnect layers in an integrated circuit. A lower barrier layer is formed from Ti. A lower adhesion-promoting layer is disposed over the lower Ti barrier layer. An antifuse material layer selected from a group comprising at least one of amorphous carbon and amorphous carbon doped with at least one of hydrogen and fluorine is disposed over the lower adhesion-promoting layer. An upper adhesion-promoting layer is disposed over the antifuse material layer. An upper Ti barrier layer is disposed over the upper adhesion-promoting layer.
1. A reprogrammable metal-to-metal antifuse comprising:
an inter-metal dielectric layer having a via formed therethrough and filled with a metal plug;
a lower Ti barrier layer disposed over said metal plug;
a lower adhesion-promoting layer disposed over said lower Ti barrier layer;
an antifuse material layer disposed above an upper surface of said lower adhesion-promoting layer, said antifuse material layer selected from a group comprising at least one of amorphous carbon and amorphous carbon doped with at least one of hydrogen and fluorine disposed over said lower adhesion-promoting layer;
an upper adhesion-promoting layer disposed over said antifuse material layer; and
an upper Ti barrier layer disposed over said upper adhesion-promoting layer,
wherein:
said lower adhesion-promoting layer and said upper adhesion-promoting layer each have a thickness of between about 2 angstroms and about 20 angstroms;
the reprogrammable metal-to-metal antifuse is programmed in response to a programming potential applied across the antifuse; and
the reprogrammable metal-to-metal antifuse is erased in response to an erasing potential, lower in magnitude than the programming potential, across the antifuse.
2. The reprogrammable metal-to-metal antifuse of claim 1 , wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer are comprised of a material selected from the group comprising Si x C y and Si x N y .
3. The reprogrammable metal-to-metal antifuse of claim 2 , wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si x C y .
4. The reprogrammable metal-to-metal antifuse of claim 3 , wherein a ratio of x to y in said Si x C y is in a range of about 1+/−0.4.
5. The reprogrammable metal-to-metal antifuse of claim 2 , wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si x N y .
6. The reprogrammable metal-to-metal antifuse of claim 5 , wherein a ratio of x to y in said Si x N y is in a range of about 0.75+/−0.225.
7. The reprogrammable metal-to-metal antifuse of claim 1 , wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer are from a material selected from the group comprising Si x C y and Si x N y .
8. The reprogrammable metal-to-metal antifuse of claim 7 , wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si x C y .
9. The reprogrammable metal-to-metal antifuse of claim 8 , wherein a ratio of x to y in said Si x C y is in a range of about 1+/−0.4.
10. The reprogrammable metal-to-metal antifuse of claim 7 , wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si x N y .
11. The reprogrammable metal-to-metal antifuse of claim 7 , wherein a ratio of x to y in said Si x N y is in a range of about 0.75+/−0.225.
12. The reprogrammable metal-to-metal antifuse of claim 1 , wherein said antifuse material layer is formed from amorphous carbon having a thickness of between about 50 angstroms and about 500 angstroms.
13. The reprogrammable metal-to-metal antifuse of claim 1 , wherein said antifuse material layer comprises amorphous carbon doped with hydrogen in a concentration range of about 1 atomic percent to about 40 atomic percent.
14. The reprogrammable metal-to-metal antifuse of claim 13 , wherein said antifuse material layer has a thickness of between about 50 angstroms and about 500 angstroms.
15. The reprogrammable metal-to-metal antifuse of claim 1 , wherein said antifuse material layer is about 50 angstroms to 500 angstroms in thickness, and said lower adhesion-promoting layer and said upper adhesion-promoting layer each have a thickness of between about 2 angstroms and about 20 angstroms.
16. The reprogrammable metal-to-metal antifuse in claim 15 , wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer are from a material selected from the group comprising Si x C y and Si x N y .
17. The reprogrammable metal-to-metal antifuse of claim 16 , wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si x C y .
18. The reprogrammable metal-to-metal antifuse of claim 17 , wherein a ratio of x to y in said Si x C y is in a range of about 1+/−0.4.
19. The reprogrammable metal-to-metal antifuse of claim 16 , wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si x N y .
20. The reprogrammable metal-to-metal antifuse of claim 19 , wherein a ratio of x to y in said Si x N y is in a range of about 0.75+/−0.225.
21. The reprogrammable metal-to-metal antifuse of claim 16 , wherein said amorphous carbon antifuse material layer is doped with hydrogen from about 1 atomic percent to about 40 atomic percent.
22. A reprogrammable metal-to-metal antifuse comprising:
a lower metal interconnect layer;
an inter-metal dielectric layer disposed over said lower metal interconnect layer, said inter-metal dielectric layer having a via formed therethrough and filled with a metal plug;
a lower Ti barrier layer disposed over said metal plug;
a lower adhesion-promoting layer disposed over said lower Ti barrier layer;
an antifuse material layer formed from amorphous carbon and disposed over said lower adhesion-promoting layer;
an upper adhesion-promoting layer disposed over said antifuse material layer;
an upper Ti barrier layer disposed over said upper adhesion-promoting layer; and
an upper metal interconnect layer disposed over said upper Ti barrier layer,
wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer each have a thickness of between about 2 angstroms and about 20 angstroms;
the reprogrammable metal-to-metal antifuse is programmed in response to a programming potential applied across the antifuse; and
the reprogrammable metal-to-metal antifuse is erased in response to an erasing potential, lower in magnitude than the programming potential, across the antifuse.
23. The reprogrammable metal-to-metal antifuse of claim 22 , wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer are comprised of a material selected from the group comprising Si x C y and Si x N y .
24. The reprogrammable metal-to-metal antifuse of claim 23 , wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si x C y .
25. The reprogrammable metal-to-metal antifuse of claim 24 , wherein a ratio of x to y in said Si x C y is in a range of about 1+/−0.4.
26. The reprogrammable metal-to-metal antifuse of claim 23 , wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si x N y .
27. The reprogrammable metal-to-metal antifuse of claim 26 , wherein a ratio of x to y in said Si x N y is in a range of about 0.75+/−0.225.
28. The reprogrammable metal-to-metal antifuse of claim 22 , wherein said antifuse material layer has a thickness of between about 50 angstroms and about 500 angstroms.
29. The reprogrammable metal-to-metal antifuse of claim 22 , wherein said amorphous carbon antifuse material layer is doped with hydrogen in a concentration range of about 1 atomic percent to about 40 atomic percent.
30. The reprogrammable metal-to-metal antifuse of claim 29 , wherein said amorphous carbon antifuse material layer has a thickness of between about 50 angstroms and about 500 angstroms.
31. The reprogrammable metal-to-metal antifuse of claim 22 , wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer are comprised of a material selected from the group comprising Si x C y , Si x N y , Si x C y N z , Si x O y C z , and Si x O y N z .
32. A reprogrammable metal-to-metal antifuse comprising:
an inter-metal dielectric layer having a via formed therethrough and filled with a metal plug;
a lower Ti barrier layer disposed over said metal plug;
a lower Si x C y layer disposed over said lower Ti barrier layer;
an antifuse material layer comprised of amorphous carbon and disposed over said lower Si x C y layer;
an upper Si x C y layer disposed over said antifuse material layer; and
an upper Ti barrier layer,
wherein said lower Si x C y layer and said upper Si x C y layer each have a thickness of between about 2 angstroms and about 20 angstroms;
the reprogrammable metal-to-metal antifuse is programmed in response to a programming potential applied across the antifuse; and
the reprogrammable metal-to-metal antifuse is erased in response to an erasing potential, lower in magnitude than the programming potential, across the antifuse.
33. A reprogrammable metal-to-metal antifuse comprising:
an inter-metal dielectric layer having a via formed therethrough and filled with a metal plug;
a lower Ti barrier layer disposed over said metal plug;
a lower Si x N y layer disposed over said lower Ti barrier layer;
an antifuse material layer comprised of amorphous carbon and disposed over said lower Si x N y layer;
an upper Si x N y layer disposed over said antifuse material layer; and
an upper Ti barrier layer,
wherein said lower Si x N y layer and said upper Si x N y layer each have a thickness of between about 2 angstroms and about 20 angstroms;
the reprogrammable metal-to-metal antifuse is programmed in response to a programming potential applied across the antifuse; and
the reprogrammable metal-to-metal antifuse is erased in response to an erasing potential, lower in magnitude than the programming potential, across the antifuse.