Airgap-containing interconnect structure with improved patternable low-K material and method of fabricating

1. An interconnect structure comprising:

at least one patterned and cured low-k dielectric material located on a surface of a patterned inorganic antireflective coating that is located atop a substrate, wherein said at least one patterned and cured low-k dielectric material and said patterned inorganic antireflective coating having conductively filled regions embedded therein and said at least one patterned and cured low-k dielectric material having at least one airgap located adjacent, but not directly abutting the conductively filled regions, and wherein the at least one patterned and cured low-k dielectric material comprises a polymer, a copolymer, a blend including at least two of any combination of polymers and/or copolymers, wherein the polymers include one monomer and the copolymers include at least two monomers and wherein the monomers of the polymers and the monomers of the copolymers are selected from a siloxane, silane, carbosilane, oxycarbosilane, silsesquioxane, alkyltrialkoxysilane, tetra-alkoxysilane, unsaturated alkyl substituted silsesquioxane, unsaturated alkyl substituted siloxane, unsaturated alkyl substituted silane, an unsaturated alkyl substituted carbosilane, unsaturated alkyl substituted oxycarbosilane, carbosilane substituted silsesquioxane, carbosilane substituted siloxane, carbosilane substituted silane, carbosilane substituted carbosilane, carbosilane substituted oxycarbosilane, oxycarbosilane substituted silsesquioxane, oxycarbosilane substituted siloxane, oxycarbosilane substituted silane, oxycarbosilane substituted carbosilane, and oxycarbosilane substituted oxycarbosilane;

a dielectric cap having a bottommost surface in direct physical contact with an uppermost surface of the at least one patterned and cured low-k dielectric material and an uppermost surface of the conductively filled region embedded in said at least one patterned and cured low-k dielectric material, said dielectric cap having an opening located therein, wherein an upper portion of the air gap is present in said opening; and

an airgap cap located directly on an uppermost surface of said dielectric cap and spanning across said opening sealing said airgap.

2. The interconnect structure of claim 1 wherein said inorganic antireflective coating comprises a composition that includes atoms of M, C (carbon) and H (hydrogen), wherein M is selected from at least one of Si, Ge, B, Sn, Fe, Ta, Ti, Ni, Hf and La, or a polymer that has at least one monomer unit comprising the formula M-R A wherein M is as defined above and R A is a chromophore.

3. The interconnect structure of claim 1 wherein said at least one patterned and cured low-k material is a patterned and cured patternable low-k material comprising a polymer wherein said polymer is described by the general formula:

wherein m and n are integers greater than zero, R 2 is a group containing at least one carbon atom, wherein R 1 is selected from the group consisting of:

4. The interconnect structure of claim 3 wherein said polymer is a first polymer of a polymer blend that further includes a second polymer, wherein said second polymer of said polymer blend is a polymer or a copolymer, wherein said polymer includes one monomer and said copolymer includes at least two of any combination monomers and wherein said monomers of said polymers and said monomers of said copolymers are selected from siloxane, silane, silsesquioxane, carbosilane, oxycarbosilane, alkyltrialkoxysilane and tetra-alkoxysilane.

5. The interconnect structure of claim 3 wherein said polymer is a first polymer of a polymer blend that further includes a second polymer, wherein said second polymer of said polymer blend is a copolymer derived from at least two of any combination of monomers selected from methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, or ethyltriethoxysilane, as an alkyltrialkoxysilane monomer, and tetra-methoxysilane or tetra-ethoxysilane, as an tetra-alkoxysilane monomer.

6. The interconnect structure of claim 3 wherein said polymer is a first polymer of a polymer blend that further includes a second polymer, wherein said second polymer of said polymer blend is a silsesquioxane polymer having the general formula:

wherein x is an integer greater than zero and R 3 is a carbon functional group comprising at least one carbon atom, wherein said second polymer is configured to undergo chemical crosslinking with said first polymer, said second polymer, or a combination thereof.

7. The interconnect structure of claim 6 wherein R 3 is selected from the group consisting of:

x is an integer from 4 to 1000.

8. The interconnect structure of claim 1 wherein said at least one patterned and cured low-k material is a patterned and cured patternable low-k material comprising a carbosilane-substituted silsesquioxane polymer having a structural formula:

wherein, a, b, and c are integers greater than zero, wherein R 4 , R 5 , R 6 , R 7 , and R 8 are carbon-containing groups, and R 9 is an alkoxy group, wherein subscripts q and r are integers in a range from 0 to 3, and wherein subscript s is an integer in a range from 1 to 3.

9. The interconnect structure of claim 8 wherein R 4 is selected from the group consisting of:

10. The interconnect structure of claim 8 wherein R 5 is selected from the group consisting of:

11. The interconnect structure of claim 8 wherein said polymer is a first polymer of a polymer blend that further includes a second polymer, wherein said second polymer of said polymer blend is a polymer or a copolymer, wherein said polymer includes one monomer and said copolymer includes at least two of any combination of monomers and wherein said monomers of said polymers and said monomers of said copolymers are selected from siloxane, silane, silsesquioxane, carbosilane, oxycarbosilane, alkyltrialkoxysilane and tetra-alkoxysilane.

12. The interconnect structure of claim 8 wherein said polymer is a first polymer of a polymer blend that further includes a second polymer, wherein said second polymer of said polymer blend is a copolymer derived from at least two of any combination of monomers selected from methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, or ethyltriethoxysilane, as an alkyltrialkoxysilane monomer, and tetra-methoxysilane or tetra-ethoxysilane, as an tetra-alkoxysilane monomer.

13. The interconnect structure of claim 12 wherein said second polymer is of said polymer blend is a silsesquioxane polymer having the general formula:

wherein x is an integer greater than zero and R 3 is a carbon functional group comprising at least one carbon atom, wherein said second polymer is configured to undergo chemical crosslinking with said first polymer, said second polymer, or a combination thereof.

14. The interconnect structure of claim 1 wherein said at least one patterned and cured low-k material is a patterned and cured positive-tone patternable low-k material comprising a polymer described by the general formula:

wherein, d and f are integers greater than zero, e is an integer greater than or equal to zero, R 12 is a carbon functionality having an acid-labile protecting group, R 14 is a carbon functionality having at least one carbon atom, and R 13 is selected from the group consisting of:

15. The interconnect structure of claim 14 wherein said polymer is a first polymer of a polymer blend that further includes a second polymer, wherein said second polymer of said polymer blend is a polymer or a copolymer, wherein said polymer includes one monomer and said copolymer includes at least two of any combination of monomers and wherein said monomers of said polymers and said monomers of said copolymers are selected from siloxane, silane, silsesquioxane, carbosilane, oxycarbosilane, alkyltrialkoxysilane and tetra-alkoxysilane.

16. The interconnect structure of claim 14 wherein said polymer is a first polymer of a polymer blend that further includes a second polymer, wherein said second polymer of said polymer blend is a copolymer derived from at least two of any combination of monomers selected from methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, or ethyltriethoxysilane, as an alkyltrialkoxysilane monomer, and tetra-methoxysilane or tetra-ethoxysilane, as an tetra-alkoxysilane monomer.

17. The interconnect structure of claim 16 wherein said second polymer is of said polymer blend is a silsesquioxane polymer having the general formula:

wherein x is an integer greater than zero and R 3 is a carbon functional group comprising at least one carbon atom, wherein said second polymer is configured to undergo chemical crosslinking with said first polymer, said second polymer, or a combination thereof.

18. An interconnect structure comprising:

a lower patterned and cured low-k material layer located directly on a surface of a patterned inorganic antireflective coating that is located atop a substrate and an abutting upper patterned and cured low-k material layer located on said lower patterned and cured low-k material layer, said lower and upper patterned and cured low-k material layers and said patterned inorganic antireflective coating having conductively filled regions and at least said upper patterned and cured low-k film having at least one airgap located adjacent, but not directly abutting the conductively filled regions, and wherein the lower and upper patterned and cured low-k dielectric materials are the same or different and comprise a polymer, a copolymer, a blend including at least two of any combination of polymers and/or copolymers, wherein the polymers include one monomer and the copolymers include at least two monomers and wherein the monomers of the polymers and the monomers of the copolymers are selected from a siloxane, silane, carbosilane, oxycarbosilane, silsesquioxane, alkyltrialkoxysilane, tetra-alkoxysilane, unsaturated alkyl substituted silsesquioxane, unsaturated alkyl substituted siloxane, unsaturated alkyl substituted silane, an unsaturated alkyl substituted carbosilane, unsaturated alkyl substituted oxycarbosilane, carbosilane substituted silsesquioxane, carbosilane substituted siloxane, carbosilane substituted silane, carbosilane substituted carbosilane, carbosilane substituted oxycarbosilane, oxycarbosilane substituted silsesquioxane, oxycarbosilane substituted siloxane, oxycarbosilane substituted silane, oxycarbosilane substituted carbosilane, and oxycarbosilane substituted oxycarbosilane;

a dielectric cap having a bottommost surface in direct physical contact with an uppermost surface of the upper patterned and cured low-k material layer and an uppermost surface of the conductively filled region embedded in said upper patterned and cured low-k material layer, said dielectric cap having an opening located therein, wherein an upper portion of the air gap is present in said opening; and

an airgap cap located directly on an uppermost surface of said dielectric cap and spanning across said opening sealing said airgap.

19. The interconnect structure of claim 18 wherein said inorganic antireflective coating comprises of a composition that includes atoms of M, C and H, wherein M is selected from at least one Si, Ge, B, Sn, Fe, Ta, Ti, Ni, Hf and La, or a polymer that has at least one monomer unit comprising the formula M-R A wherein M is as defined above and R A is a chromophore.

20. A method of fabricating an interconnect structure comprising:

providing at least one patternable low-k material directly on a surface of an inorganic antireflective coating (ARC) that is located atop a substrate, wherein said at least one patternable low-k dielectric material comprises a polymer, a copolymer, a blend including at least two of any combination of polymers and/or copolymers, wherein the polymers include one monomer and the copolymers include at least two monomers and wherein the monomers of the polymers and the monomers of the copolymers are selected from a siloxane, silane, carbosilane, oxycarbosilane, silsesquioxane, alkyltrialkoxysilane, tetra-alkoxysilane, unsaturated alkyl substituted silsesquioxane, unsaturated alkyl substituted siloxane, unsaturated alkyl substituted silane, an unsaturated alkyl substituted carbosilane, unsaturated alkyl substituted oxycarbosilane, carbosilane substituted silsesquioxane, carbosilane substituted siloxane, carbosilane substituted silane, carbosilane substituted carbosilane, carbosilane substituted oxycarbosilane, oxycarbosilane substituted silsesquioxane, oxycarbosilane substituted siloxane, oxycarbosilane substituted silane, oxycarbosilane substituted carbosilane, and oxycarbosilane substituted oxycarbosilane;

forming at least one interconnect pattern within said at least one patternable low-k material, said at least one interconnect pattern is formed without utilizing a separate photoresist material;

curing said at least one patterned patternable low-k material into a dielectric material having a dielectric constant of not more than 4.3;

filling said at least one interconnect pattern with an electrically conductive material;

forming a stack comprising a dielectric cap and a block mask located atop said at least one cured patternable-low-k dielectric material;

forming at least one airgap through said stack and into said at least one patterned and cured patternable low-k dielectric material, wherein an upper portion of said at least one airgap is present in an opening formed into said dielectric cap, and wherein said forming the at least one airgap comprises defining an airgap pattern into said at least one patterned and cured patternable low-k dielectric material by lithography and etching, removing said block mask, chemical treating portions of the at least one patterned and cured patternable low-k dielectric material that are located directly abutting the airgap pattern to change the etch rate of the chemical treatment portions of the at least one patterned and cured patternable low-k dielectric material, and removing the chemical treated portions by performing another etch; and

forming an airgap cap atop said dielectric cap of said stack, wherein a portion of said airgap cap spans across said opening sealing said airgap.

21. The method of claim 20 wherein said inorganic antireflective coating comprises a composition that includes atoms of M, C and H, wherein M is selected from at least one of Si, Ge, B, Sn, Fe, Ta, Ti, Ni, Hf and La, or a polymer that has at least one monomer unit comprising the formula M-R A wherein M is as defined above and R A is a chromophore.

22. A method of fabricating a dual-damascene interconnect structure comprising:

providing a first patternable low-k material on a surface of an inorganic antireflective coating (ARC) that is located directly atop a substrate;

forming first interconnect patterns within the first patternable low-k material without a separate photoresist;

providing a second patternable low-k material on top of the first patterned patternable low-k material including said first interconnect patterns;

forming second interconnect patterns within said second patternable low-k material without a separate photoresist;

curing at least said second patterned patternable low-k material;

filling said first and second interconnect patterns with an electrically conductive material;

forming a stack comprising a dielectric cap and a block mask located atop said cured second patternable low-k dielectric material;

forming at least one airgap through said stack and into at least said patterned and cured second patternable low-k dielectric material, wherein an upper portion of said at least one airgap is present in an opening formed into said dielectric cap, and wherein said forming the at least one airgap comprises defining an airgap pattern into said at least one patterned and cured second patternable low-k dielectric material by lithography and etching, removing said block mask, chemical treating portions of the at least one patterned and cured second patternable low-k dielectric material that are located directly abutting the airgap pattern to change the etch rate of the chemical treatment portions of the at least one patterned and cured second patternable low-k dielectric material, and removing the chemical treated portions by performing another etch; and

forming an airgap cap atop said dielectric cap of said stack, wherein a portion of said airgap cap spans across said opening sealing said airgap, and wherein the first and second patternable low-k materials are the same or different and comprise a polymer, a copolymer, a blend including at least two of any combination of polymers and/or copolymers, wherein the polymers include one monomer and the copolymers include at least two monomers and wherein the monomers of the polymers and the monomers of the copolymers are selected from a siloxane, silane, carbosilane, oxycarbosilane, silsesquioxane, alkyltrialkoxysilane, tetra-alkoxysilane, unsaturated alkyl substituted silsesquioxane, unsaturated alkyl substituted siloxane, unsaturated alkyl substituted silane, an unsaturated alkyl substituted carbosilane, unsaturated alkyl substituted oxycarbosilane, carbosilane substituted silsesquioxane, carbosilane substituted siloxane, carbosilane substituted silane, carbosilane substituted carbosilane, carbosilane substituted oxycarbosilane, oxycarbosilane substituted silsesquioxane, oxycarbosilane substituted siloxane, oxycarbosilane substituted silane, oxycarbosilane substituted carbosilane, and oxycarbosilane substituted oxycarbosilane.

23. The method of claim 22 wherein said inorganic antireflective coating comprises a composition that includes atoms of M, C and H, wherein M is selected from at least one of Si, Ge, B, Sn, Fe, Ta, Ti, Ni, Hf and La, or a polymer that has at least one monomer unit comprising the formula M-R A wherein M is as defined above and R A is a chromophore.