Residual stress in thin-film parylene-c

Abstract

This paper reports the influence of thermal annealing on the residual stress in parylene-c thin-films on silicon. Although recently others have used the diaphragm bulge testing method to measure the residual stress in parylene, this is the first extensive study of residual stress in parylene using the load-deflection method and rotating tip strain gages. This paper supports the hypothesis that stress is relaxed in parylene-c films at elevated temperatures (>100/spl deg/C) and that thermal stress accounts for 90% of the residual stress in films that have undergone annealing at these elevated temperatures. It was found that this held true up to 180/spl deg/C which is above the glass transition temperature of the material.