Patternable low dielectric constant materials and their use in ULSI interconnection
View Patent ↗The present invention relates to ultra-large scale integrated (ULSI) interconnect structures, and more particularly to patternable low dielectric constant (low-k) materials suitable for use in ULSI interconnect structures. The patternable low-k dielectrics disclosed herein are functionalized polymers that having one or more acid-sensitive imageable functional groups.
1. A film stack comprising:
a cured and patterned low-k material located on a substrate, said cured and patterned low-k material having a dielectric constant of less than 3.9 and comprising a functionalized polymer having one or more acid-sensitive imageable groups, wherein said functionalized polymer is a linear, branched or caged silsesquioxane polymer including combinations thereof having the formula:
wherein each occurrence of R 1 is independently one or more acidic functional groups; each occurrence of R 2 independently comprises at least one acid-sensitive imageable functional group; R 1 is not equal to R 2 ; m and n represent the number of repeating units; m is an integer; and n is zero or an integer greater than zero; and
an overlying layer atop said cured and patterned low-k material.
2. The film stack of claim 1 further comprising a conductive material embedded in said cured and patterned low-k material.
3. The film stack of claim 1 located in a dual damascene interconnect structure.
4. The film stack of claim 1 wherein each occurrence of R 1 independently comprises a linear or branched alkyl which is substituted with at least one of OH, —C(O)OH, and F; a cycloalkyl which is substituted with at least one of —OH, —C(O)OH and —F; an aromatic which is substituted with at least one of —OH, —C(O)OH, and —F; an arene that is substituted with at least one of —OH, —C(O)OH and —F; or an acrylic that is substituted with at least one of —OH, —C(O)OH and —F.
5. The film stack of claim 1 wherein each occurrence of R 1 independently is one of the formula moieties:
6. The film stack of claim 1 wherein each occurrence of R 2 independently is one or more acid-sensitive functional groups.
7. The film stack of claim 1 wherein each occurrence of R 2 independently comprises one of the following:
wherein R 10 is any R 2 group and t is from 1 to 20.
8. The film stack of claim 1 wherein R 2 further comprises an acid-sensitive protecting group.
9. The film stack of claim 8 wherein said acid-sensitive protecting group comprises cyclic or branched aliphatic carbonyls, tertiary esters, or tertiary ethers.
10. The film stack of claim 9 wherein said R 2 is one of the following moieties:
wherein R 5 and R 6 are cyclic or branched aliphatic carbonyls, tertiary esters, or tertiary ethers.
11. The film stack of claim 1 wherein said patternable low-k composition further comprises a photosensitive acid generator and a solvent.
12. The film stack of claim 11 further comprising an acid sensitive crosslinking agent.
13. The film stack of claim 1 wherein said functionalized polymer is a caged silsesquioxane polymer.
14. The film stack of claim 1 wherein said cured and patterned low-k material is porous.
15. The film stack of claim 1 wherein said acid-sensitive imageable functional group is selected from a linear or branched alkyl that is substituted with at least one of —OH, epoxide, or —F; a cyclo aromatic that is substituted with at least one of —OH, epoxide, or —F; or an arene that is substituted with at least one of —OH, epoxide, or —F.
16. The film stack of claim 1 wherein said dielectric constant is less than 3.0.
17. A film stack comprising:
a cured and patterned low-k material located on a substrate, said cured and patterned low-k material is porous, has a dielectric constant of less than 3.9 and comprises a functionalized polymer having one or more acid-sensitive imageable groups, wherein said functionalized polymer is a linear, branched or caged silsesquioxane polymer including combinations thereof having the formula:
wherein each occurrence of R 1 is independently one or more acidic functional groups; each occurrence of R 2 independently comprises at least one acid-sensitive imageable functional group;
R 1 is not equal to R 2 ; m and n represent the number of repeating units; m is an integer; and n is zero or an integer greater than zero;
a conductive material embedded within the cured and patterned low-k material; and
an overtying layer atop at least said cured and patterned low-k material.