Adamantyl-based benzocyclobutene low-k polymers with good physical properties and excellent planarity

Abstract

Low dielectric polymers play an important role in replacing traditional inorganic dielectric materials in advanced electronic manufacturing due to their excellent physical and chemical properties. Herein we report the preparation and characterization of two novel low-k dielectric polymers by introducing adamantane into benzocyclobutene. Because the adamantyl group has low polarizability and can increase the free volume of the polymer, both polymers showed low dielectric constants (2.5) and low dielectric loss (o0.001) at the frequency within 10 KHz-5 MHz. They also showed excellent film uniformity and planarity with the surface roughness less than 0.6 nm and good hydrophobicity with the contact angle larger than 1071. Due to the high cross-linked network structure, both of the adamantylbased BCB polymers exhibited high glass transition temperature (4350 1C), high storage modulus and good thermal stability (T d 4 400 1C in nitrogen). Especially, the p-Ada-TVS-BCB polymer showed a low coefficient of thermal expansion (41 mm m À1 1C À1 ). All of these good properties are in accord with the requirement of the interconnect fabrication of Cu metallization using the damascene process. Both of the polymers are suitable for the utilization in the electronic packing industry.

Materials containing benzocyclobutene units with low dielectric constant and good thermostability prepared from star‐shaped molecules

“…The band at 1495 cm −1 may be attributed to the formation of the tetrahydronaphthalene structure during curing . The peaks at 2825 cm −1 , which are assigned to the stretching vibration of C─H in the four‐membered ring of benzocyclobutene, disappeared after the monomers were cured . All of the above‐mentioned results support the idea that TDSDES‐BCB and THSV‐BCB could be cured.…”

“…However, cured THSV‐BCB shows rigid units different from cured TDSDES‐BCB (Scheme ). When the temperature was above 200 °C, the four‐membered ring of benzocyclobutene opened and formed an o ‐quinodimethane active intermediate, which could couple with itself or react with other olefins by [4+2] cycloaddition . DSC curves [Figure (a,b)] of TDSDES‐BCB and THSV‐BCB show similar exothermic peaks with an onset at 200 °C and a maximum at 251 °C and 259 °C, respectively.…”

Preparation of planar and hydrophobic benzocyclobutene‐based dielectric material from biorenewable rosin

“…The characteristic peaks for the BCB group at 1467 cm −1 disappear after the curing reaction. Moreover, the characteristic peak of BCB monomers at 1467 cm −1 is transferred to 1500 cm −1 after the polymerization . This result suggests that the monomer has been fully converted to a cured resin.…”

“…The hydrogenated phenanthrene ring, as a characteristic functional group of rosin, significantly affects the hydrophobic and thermomechanical properties of polymers . Moreover, as the primary structural unit of target polymer, the huge hydrogenated phenanthrene ring structure can effectively block the winding of molecular segments, which increases the intermolecular spacing and free volume in polymer molecules . Therefore, the introduction of the hydrogenated phenanthrene ring might yield the BCB resins with good hydrophobic, thermomechanical, and dielectric properties.…”

Robust spin-on-glass poly(methyl)silsesquioxane-based low-k materials derived from a cyclic siloxane precursor

“…Several groups have reported on the low-dielectric properties of benzoxazinefunctionalized polysilsesquioxanes, 16,17 cyanate ester composites, 18 as well as the functionalization of benzocyclobutene 19 to the Si-O-Si backbone to utilize the high free-volume of the crosslinked organic components to substantially lower the dielectric constants. Several groups have reported on the low-dielectric properties of benzoxazinefunctionalized polysilsesquioxanes, 16,17 cyanate ester composites, 18 as well as the functionalization of benzocyclobutene 19 to the Si-O-Si backbone to utilize the high free-volume of the crosslinked organic components to substantially lower the dielectric constants.…”