Graphene enabled selective barrier layer formation
Interconnect structures and method of forming the same are disclosed herein. An exemplary interconnect structure includes a first contact feature in a first dielectric layer, a second dielectric layer over the first dielectric layer, a second contact feature over the first contact feature, a barrier layer between the second dielectric layer and the second contact feature, and a graphene layer between the second contact feature and the first contact feature.
1. An interconnect structure comprising:
a first contact feature in a first dielectric layer;
a second dielectric layer over the first dielectric layer;
a second contact feature over the first contact feature;
a barrier layer between the second dielectric layer and the second contact feature; and
a carbon layer disposed between the second contact feature and the first contact feature, the carbon layer being in contact with the second contact feature,
wherein the barrier layer terminates over a top surface of the carbon layer and does not extend between the second contact feature and the carbon layer.
2. The interconnect structure of claim 1 , wherein the carbon layer comprises a graphene layer.
3. The interconnect structure of claim 1 , wherein the barrier layer comprises cobalt-tungsten alloy, cobalt-manganese alloy, copper-aluminum alloy, nickel-aluminum alloy, or a combination thereof.
4. The interconnect structure of claim 1 , wherein the barrier layer comprises titanium nitride, tantalum nitride, cobalt nitride, tungsten nitride, ruthenium nitride, or a combination thereof.
5. The interconnect structure of claim 1 , further comprising a catalytic metal layer disposed between the carbon layer and the first contact feature.
6. The interconnect structure of claim 5 , wherein the catalytic metal layer comprises nickel, cobalt, copper, ruthenium, platinum, or gold.
7. The interconnect structure of claim 1 , wherein an interface between the carbon layer and the second contact feature is free of the barrier layer.
8. An interconnect structure comprising:
a first contact feature in a first dielectric layer;
a second dielectric layer over the first dielectric layer;
a contact via over the first contact feature and surrounded by the second dielectric layer;
a second contact feature over the contact via and surrounded by the second dielectric layer;
a barrier layer between the second dielectric layer and the second contact feature; and
a graphene layer disposed between the contact via and the second contact feature, the graphene layer being in contact with the second contact feature,
wherein the barrier layer terminates over a top surface of the graphene layer and does not extend between the contact via and the second contact feature.
9. The interconnect structure of claim 8 , wherein the graphene layer does not extend between the second dielectric layer and the barrier layer.
10. The interconnect structure of claim 8 , wherein the barrier layer comprises cobalt-tungsten alloy, cobalt-manganese alloy, copper-aluminum alloy, nickel-aluminum alloy, or a combination thereof.
11. The interconnect structure of claim 8 , wherein the barrier layer comprises titanium nitride, tantalum nitride, cobalt nitride, tungsten nitride, ruthenium nitride, or a combination thereof.
12. The interconnect structure of claim 8 , wherein an interface between the graphene layer and the second contact feature is free of the barrier layer.
13. The interconnect structure of claim 8 , further comprising a catalytic metal layer disposed between the graphene layer and the contact via.
14. The interconnect structure of claim 13 , wherein the catalytic metal layer comprises nickel, cobalt, copper, ruthenium, platinum, or gold.
15. The interconnect structure of claim 13 , wherein the catalytic metal layer is different from the second contact feature in terms of composition.
16. A contact structure, comprising:
a first contact feature in a first dielectric layer;
an etch stop layer over the first dielectric layer;
a graphene layer disposed over the first contact feature;
a catalytic metal layer disposed between the graphene layer and the first contact feature, a composition of the catalytic metal layer being different from a composition of the first contact feature;
a second dielectric layer over the etch stop layer;
a second contact feature over the graphene layer and disposed in the second dielectric layer; and
a barrier layer between the second dielectric layer and the second contact feature.
17. The contact structure of claim 16 , further comprising:
wherein the catalytic metal layer is monocrystalline.
18. The contact structure of claim 17 , wherein the catalytic metal layer comprises nickel, cobalt, copper, ruthenium, rhenium, rhodium, palladium, iridium, platinum, or gold.
19. The contact structure of claim 16 ,
wherein the barrier layer terminates over a top surface of the graphene layer and does not extend over a top surface of the first contact feature.
20. The contact structure of claim 19 , wherein the barrier layer comprises a cobalt-tungsten alloy (CoW), a cobalt-manganese alloy (CoMn), a copper-aluminum alloy (CuAl), a nickel-aluminum alloy (NiAl), tantalum nitride (TaN), titanium nitride (TiN), cobalt nitride (CoN), ruthenium nitride (RuN), or nickel nitride (NiN).