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

Abstract

The present invention provides a method of fabricating an airgap-containing interconnect structure in which a patternable low-k material replaces the need for utilizing a separate photoresist and a dielectric material. Specifically, this invention relates to a simplified method of fabricating single-damascene and dual-damascene airgap-containing low-k interconnect structures with at least one patternable low-k dielectric and at least one inorganic antireflective coating.

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 inorganic antireflective coating comprises atoms of M, C and H wherein M is at least one of Si, Ge, B, Sn, Fe, Ta, Ti, Ni, Hf and La, said at least one cured and patterned low-k dielectric material and said patterned inorganic antireflective coating having conductively filled regions embedded therein and said at least one cured and patterned low-k dielectric material having at least one airgap located adjacent, but not directly in contact with the conductively filled regions.   
     
     
         2 . The interconnect structure of  claim 1  wherein said inorganic antireflective coating further comprises atoms of O, N, S, F or mixtures thereof. 
     
     
         3 . The interconnect structure of  claim 1  wherein said at least one patterned and cured low-k dielectric material comprises a cured functionalized polymer having one or more irradiation/acid-sensitive imageable groups. 
     
     
         4 . The interconnect structure of  claim 3  wherein said functionalized polymer comprises a polymer of a hydrocarbon, a fluorinated hydrocarbon, a siloxane, a silane, a carbosilane, an oxycarbosilane, an organosilicate or a silsesquioxane. 
     
     
         5 . The interconnect structure of  claim 3  wherein said functionalized polymer further comprises a functionalized sacrificial pore generator. 
     
     
         6 . The interconnect structure of  claim 1  further comprising a dielectric cap located on an uppermost surface of said at least one patterned and cured low-k dielectric material, said dielectric cap having an opening in which an upper portion of the at least one airgap extends through. 
     
     
         7 . The interconnect structure of  claim 6  further comprising an airgap cap located atop said dielectric cap and atop said opening, wherein a portion of said airgap cap located at said opening is in contact with said upper portion of the airgap. 
     
     
         8 . The interconnect structure of  claim 1  wherein said airgap is filled with air. 
     
     
         9 . The interconnect structure of  claim 1  wherein said airgap is a vacuum. 
     
     
         10 . An interconnect structure comprising:
 a lower patterned and cured low-k material layer located on a surface of a patterned inorganic antireflective coating that is located atop a substrate, wherein said inorganic antireflective coating comprises atoms of M, C and H wherein M is at least one of Si, Ge, B, Sn, Fe, Ta, Ti, Ni, Hf and La, 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.   
     
     
         11 . The interconnect structure of  claim 10  wherein said inorganic antireflective coating further comprises atoms of O, N, S, F or mixtures thereof. 
     
     
         12 . The interconnect structure of  claim 10  wherein said lower and upper patterned and cured low-k dielectric material layers each comprise a cured functionalized polymer having one or more irradiation/acid-sensitive imagable groups. 
     
     
         13 . The interconnect structure of  claim 10  wherein said functionalized polymer comprises a polymer of a hydrocarbon, a fluorinated hydrocarbon, a siloxane, a silane, a carbosilane, an oxycarbosilane, an organosilicate or a silsesquioxane. 
     
     
         14 . The interconnect structure of  claim 10  wherein said conductively filled regions within said lower patterned and cured low-k dielectric material layer are conductively filled vias, and said conductively filled regions within said upper patterned and cured low-k dielectric material layer are conductively filled lines. 
     
     
         15 . The interconnect structure of  claim 10  further comprising a dielectric cap located on an uppermost surface of said upper patterned and cured low-k material layer, said dielectric cap having an opening in which an upper portion of the at least one airgap extends through. 
     
     
         16 . The interconnect structure of  claim 15  further comprising an airgap cap located atop said dielectric cap and atop said opening, wherein a portion of said airgap cap located at said opening is in contact with said upper portion of the airgap. 
     
     
         17 . The interconnect structure of  claim 10  wherein said airgap is filled with air. 
     
     
         18 . The interconnect structure of  claim 10  wherein said airgap is a vacuum. 
     
     
         19 . The interconnect structure of  claim 10  wherein a first portion of said airgap is present within said lower patterned and cured low-k material layer, and a second portion of said airgap is present within said upper patterned and cured low-k material layer. 
     
     
         20 . The interconnect structure of  claim 19  wherein said conductively filled region in said upper patterned and cured low-k material is a conductively filled line, and wherein said second portion of said airgap is located adjacent to, but not in contact with, said conductively filled line.