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 composition of matter comprising a cured and functionalized polymer having one or more acid-sensitive imageable groups, wherein said polymer has a dielectric constant of less than 3.9 wherein said functionalized polymer is a caged silsesquioxane polymer including combinations thereof having the formula:
wherein each occurrence of R 1 is independently one or more acidic functional groups for base solubility; each occurrence of R 2 independently comprises at least one acid-sensitive imageable functional group for crosslinkin; 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, wherein said acid-sensitive imageable functional group for crosslinking is selected from a linear or branched alkyl that is substituted with at least one of —OH, epoxide, or —F; a cycloalkyl which 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.
2. The composition of matter 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, or —F; a cycloalkyl which is substituted with at least one of —OH, —C(O)OH or —F; an aromatic which is substituted with at least one of —OH, —C(O)OH, or —F; an arene that is substituted with at least one of —OH, —C(O)OH or —F; or an acrylic that is substituted with at least one of —OH, —C(O)OH or —F.
3. The composition of matter of claim 1 wherein each occurrence of R 1 independently is one of the formula moieties:
4. The composition of matter of claim 1 wherein each occurrence of R 2 independently is one or more acid-sensitive functional groups for crosslinking.
5. The composition of matter 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.
6. The composition of matter of claim 1 wherein R 2 further comprises an acid-sensitive protecting group.
7. The composition of matter of claim 6 wherein said acid-sensitive protecting group comprises cyclic or branched aliphatic carbonyls, tertiary esters, or tertiary ethers.
8. The composition of matter of claim 7 wherein said R 2 is one of the following moieties:
wherein R 5 and R 6 cyclic or branched aliphatic carbonyls, tertiary esters, or tertiary ethers.
9. A patternable low-k composition comprising (a) a polymer component, (b) a photosensitive acid generator, and (c) a solvent, said polymer component comprising 5 to 100 wt. % of the composition of matter of claim 1 .
10. The patternable low-k composition of claim 9 further comprising an acid-sensitive crosslinking agent.
11. The patternable low-k composition of claim 9 further comprising 0–95 wt. % of a non-silsesquioxane polymer.
12. The pattemable low-k composition of claim 9 further comprising 0.1–99.9 wt. % of a porogen.
13. The patternable low-k composition of claim 12 wherein said porogen is a homopolymer; copolymer; block copolymer; di-block or triblock copolymer; linear, star or hyperbranched polymer, dendrimer; crosslinked polymer; non-crosslinked polymer or combinations thereof.