The low dielectric constant hyperbranched polycarbosilane derived resins with spacing groups

Abstract

The route via the cross-linking of hyperbranched prepolymers has potential advantage to construct low dielectric constant (low-k) resins owing to the enhanced molecular free volume in hyperbranched structure. However, it is still a challenge to prepare hyperbranched resins with good film-forming property and low-k. In this paper, two hyperbranched polycarbosilanes with reactive benzocyclobutene groups were synthesized via hydrosilylation reaction to avoid the generation of Si O bonds for enabling the low polarity of chemical bonds. The spacing groups including phenyl or ethylene were incorporated into the hyperbranched structures, and the effect of the spacing groups on the physicochemical properties of hyperbranched polycarbosilane derived resins were investigated. The phenyl groups were found to effectively decrease the dielectric constant (k), while endowing the resins with good film forming ability and thermostability. The UV/thermally cured phenyl group resin owing to dual crosslinked structure, the patterns would not be deformed significantly during thermally cured process. Both hyperbranched polycarbosilane derived resins could be potential photoresists.

Cross-Linking Behavior and Effect on Dielectric Characteristics of Benzocyclobutene-Based Polycarbosiloxanes

“…In Figure d, vitreous resins ( AB-BCB-50 , AB-BCB-70 , and AB-BCB-100 ) showed a low and steady dielectric loss (<0.002) in a wide range of frequencies. The dielectric loss decreased significantly as the cross-linking density increased because constraining the mobility of molecular chains can minimize orientation polarization . Nevertheless, AB-BCB-10 and AB-BCB-30 with low cross-linking densities exhibited irregularly large fluctuations in dielectric loss because the free chain segments were more susceptible to frequency interference compared to that of the highly cross-linked polymers.…”

Oxygen-free polymers: new materials with low dielectric constant and ultra-low dielectric loss at high frequency

“…It can be seen that the polymers display contact angles higher than 96°, suggesting their good surface hydrophobicity. 28,29 Thus, good surface hydrophobicity can prevent water from penetrating into the polymers and endow the polymers with desirable water repellency, contributing to achieving low water uptake. These results imply that the two polymers are suitable for use as protecting materials against moisture.…”