Development of Techniques to Quantify Chemical and Mechanical Modifications of Polymer Surfaces: Application to Chemical Mechanical Polishing

Abstract

This thesis is devoted to development of techniques to quantify chemical and mechanical influences during chemical mechanical polishing (CMP) near the surface of a polymer film, poly (biphenyl dianhydride-p-phenylenediamine) (BPDA-PDA). To quantify chemical modifications during CMP, an iterative algorithm has been proposed to extract depth profiles based on Ficks second law of diffusion in a multi-element system from data supplied by angle resolved x-ray photoelectron spectroscopy. It has been demonstrated that the technique can be used to quantify the depth of chemical modification of BPDA-PDA surfaces treated with alkaline solutions. Polymer chains near the surface realign themselves during CMP and polarized infrared spectroscopy is chosen in this thesis to quantify chain orientations induced by CMP to evaluate the mechanical influence. A theoretical framework based on a 44 matrix method for spectral simulation together with an oscillator model for BPDA-PDA has been used to obtain quantitative chain orientation information on a post-CMP BPDA-PDA sample by fitting simulated polarized infrared spectra to experimentally generated spectra. Verification of the oscillator model was established from the complex refractive indices of BPDA-PDA films, which were determined using a new method (R/T ratio method) developed in this thesis to extract complex refractive indices of films with biaxial symmetry from polarized transmission and reflection spectra.