Adhesion Evaluation of PMMA/Silicon Film Structures
Hyeong Sick Ju
Bernhard R. Tittmann
Abstract
As the thin film technology has emerged in various fields, adhesion of the film interface becomes an important issue in terms of the longevity and durability of thin film devices. Diverse nondestructive methods utilizing acoustic techniques have been developed to assess the interfacial
integrity. As an effective technique based on the ultrasonic wave focusing and the surface acoustic wave (SAW) generation, scanning acoustic microscopy (SAM) has been investigated for adhesion evaluation. Visualization of film microstructures and quantification of adhesion weakness levels
by the SAW dispersion are the recent achievements of SAM. To overcome the limitations in the theoretical dispersion model only suitable for perfectly elastic and isotropic materials, a new model has been more recently developed in consideration of film anisotropy and viscoelasticity and applied
to the adhesion evaluation of polymeric films fabricated on semiconductor wafers.