Benzocyclobutenyl Silicone-Acrylic Resin: A Photo/Thermal Curing Hybrid Structure for High-Performance Photoimageable Dielectrics.

Abstract

Advancements in integrated circuit technology have heightened the importance of photoresist materials with superior dielectric properties, thermal stability, and patterning precision. Although traditional acrylic resins exhibit excellent photo-curing characteristics, their high dielectric constants, limited thermal stability, and hygroscopic nature restrict their utility in semiconductor applications. In this study, 4-acryloylbenzocyclobutene (BCB-V-COOH) was synthesized via a Heck reaction between 4-bromobenzocyclobutene and acrylic acid. Subsequently, BCB-V-COOH was copolymerized with bisbenzocyclobutene-bis-divinylsiloxane (DVS-b-BCB) at varying ratios to produce the oligomer BCB-SO-COOH. These oligomers were then graft-modified with glycidyl methacrylate to yield BSA Resin, which was blended with the photoinitiator to formulate photoresists. The structures of the BSA Resins were characterized using proton nuclear magnetic resonance (¹H NMR) and Fourier transform infrared (FTIR) spectroscopy. Studies on the photo-thermal curing kinetics revealed that the acrylate double bonds rapidly crosslinked under 365 nm UV irradiation, while the BCB moieties formed crosslinked networks via a ring-opening mechanism during thermal curing. The incorporation of BCB significantly enhanced the thermal stability and dielectric properties of the BSA Resins. Moreover, the BSA Resin achieved a patterning resolution of 10 µm with exceptional dimensional stability. Therefore, this work demonstrates the promising potential of BSA Resin for applications in microelectronic packaging.