Analysis of Mode I and II Crack tip Stress Fields for MEMS Structures with Cubic Elastic Anisotropy

Abstract

This paper addresses analysis of mode I and II crack tip singular stress fields in single crystal silicon and 3C-SiC used as MEMS mechanical structures. Fundamental solutions of anisotropic elastic fields of isolated dislocations obtained by Eshelby, Hirth and Lothe were used to derive the closed form crack tip singular stress fields. It was concluded that three elastic stiffness coefficients of diamond lattice structure have important role to control the crack tip singular stress fields, and maximum hoop stress for mixed mode proposed by Erdogan and Sih.