Experimental and Theoretical Investigations of Cured and Uncured Disiloxane Bisbenzocyclobutene Thin Films

Abstract

The main challenge in the large-scale commercial applications of benzocyclobutene (BCB) dielectrics is to perform their curing rapidly and efficiently at low temperatures, and in the same time, to obtain large area, high quality, pinhole free dielectric thin films. For that purpose, we investigated numerous uncured and cured BCB films, approximately 2 µm thick, spin-coated on glass/ITO surface, using optical and AFM microscopy, infrared (IR) and Raman spectroscopy, and complete these results with appropriate Linear Combination of Atomic Orbitals (LCAO) calculations. That way we relate microscopic characteristics of the involved molecules, and macroscopic properties of the cured and uncured polymers, which is important for their practical applications.

Keywords:

• AFM
• Calculations
• Curing
• Disiloxane bisbenzocyclobutene
• IR and Raman spectroscopy
• Thin films

ACKNOWLEDGMENTS

This work is supported by Ministry of Science and Technological Development of Republic of Serbia under the grant 141009-Physics. The authors are indebted to Dr. Alberto Montaigne Ramil for his help in analyses of AFM results.

Notes

E _t  = total energy, E _b  = bonding energy, ΔH = enthalpy of formation, MP2 = Moller-Plasset correlation energy, h ν _o  = zero-point vibrational energy (all in units of [kcal/mol]), I = first ionisation potential, µ = dipole moment.

∗Bonds unique for PBCB_1 molecule, appeared after the first step of polymerization.