Method of semiconductor integrated circuit fabrication
A method of fabricating a semiconductor integrated circuit (IC) is disclosed. The method includes providing a substrate and depositing a conductive layer on the substrate. A patterned hard mask and a catalyst layer are formed on the conductive layer. The method further includes growing a plurality of carbon nanotubes (CNTs) from the catalyst layer and etching the conductive layer by using the CNTs and the patterned hard mask as an etching mask to form metal features.
1. A method comprising:
forming a conductive layer on a semiconductor substrate;
forming a patterned material layer on the conductive layer;
forming a catalyst layer on the conductive layer;
forming a plurality of carbon nanotubes (CNTs) from the catalyst layer; and
removing the conductive layer by using the CNTs as a mask to form conductive features.
2. The method of claim 1 , wherein forming the patterned material layer on the conductive layer includes:
forming a photosensitive layer directly on the conductive layer; and
patterning the photosensitive layer, wherein the patterned photosensitive layer includes an opening exposing a portion of the conductive layer.
3. The method of claim 2 , wherein forming the catalyst layer on the conductive layer includes forming the catalyst layer within the opening of the patterned photosensitive layer and directly on the exposed portion of the conductive layer.
4. The method of claim 3 , wherein the catalyst layer only partially fills the opening.
5. The method of claim 1 , removing the material layer prior to forming the plurality of carbon nanotubes (CNTs) from the catalyst layer.
6. The method of claim 5 , wherein removing the material layer includes completely removing the material layer to expose portions of the conductive layer.
7. The method of claim 1 , further comprising forming another patterned material layer on the conductive layer prior to forming the patterned material layer on the conductive layer such that the patterned material layer is disposed directly over at least a portion of the another patterned material layer.
8. The method of claim 7 , wherein etching the conductive layer by using the CNTs as the etching mask to form metal features includes removing the conductive layer by using the CNTs and the another material layer as the mask.
9. A method comprising:
forming a conductive layer on a semiconductor substrate;
forming a patterned hard mask layer directly on the conductive layer;
forming a patterned photosensitive layer directly on the patterned hard mask layer;
forming a catalyst layer directly on the conductive layer;
forming a plurality of carbon nanotubes (CNTs) from the catalyst layer; and
removing the conductive layer by using the CNTs as a mask to form conductive features.
10. The method of claim 9 , wherein forming the patterned photosensitive layer directly on the patterned hard mask layer further includes forming the patterned photosensitive layer directly on the conductive layer.
11. The method of claim 9 , wherein the patterned photosensitive layer includes an opening, and
wherein forming the catalyst layer directly on the conductive layer includes forming the catalyst layer in the opening of the patterned photosensitive layer such that the catalyst layer physically contacts the patterned photosensitive layer.
12. The method of claim 9 , further comprising completely removing the patterned photosensitive layer prior to forming the plurality of CNTs from the catalyst layer.
13. The method of claim 9 , wherein the catalyst layer includes a metal selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni) and molybdenum (Mo).
14. The method of claim 9 , further comprising forming an interlayer dielectric layer over the patterned hard mask layer after removing the conductive layer by using the CNTs as the mask to form conductive features.
15. A method comprising:
forming a metal layer on a semiconductor substrate;
forming a patterned hard mask layer directly on the metal layer;
forming a patterned photosensitive layer directly on the patterned hard mask layer;
forming a catalyst layer directly on the metal layer through the patterned photosensitive layer and the patterned hard mask layer;
forming a plurality of carbon nanotubes (CNTs) from the catalyst layer; and
etching the metal layer by using the CNTs as a mask.
16. The method of claim 15 , wherein etching the metal layer by using the CNTs as the mask includes performing a dry etching process.
17. The method of claim 15 , further comprising removing the patterned photosensitive layer prior to forming the plurality of CNTs from the catalyst layer.
18. The method of claim 15 , wherein forming the plurality of CNTs from the catalyst layer includes heating the catalyst layer and the substrate to about 700° C. and providing at least one gas selected from the group consisting of ammonia gas, nitrogen gas, and hydrogen gas.
19. The method of claim 15 , wherein forming the patterned photosensitive layer directly on the patterned hard mask layer further includes forming the patterned photosensitive layer directly on the metal layer.
20. The method of claim 15 , wherein etching the metal layer by using the CNTs as the mask forms a conductive feature that is part of an interconnect structure of a device.