3D Crystalline Structures of Stress Induced Voiding in Cu Interconnects by Focused Ion Beam and Electron Backscattered Diffraction

The planar and cross-sectional crystalline analyses were performed on the stress induced voiding (SIV). The SIV was initiated at the triple junction of grain boundaries, not at the junction of twin and grain boundaries. The void grew preferentially in one of the grains joining at the triple junction. From stress calculation based on the measured crystalline structure, the voided grain is the stress concentration