Controlled nanocrack patterns for nanowires

Recent experiments have shown a new approach of nanowire fabrication by filling cracks with semiconductor materials or metals. Full exploration of this approach calls for a computational model to predict the crack patterns in a thin film. This paper considers crack propagation in a heterogeneous thin film with etched space and stressers for cracking guidance. A phase field model applicable to multiple materials is proposed, which eliminates the need of explicit crack front tracking. The elastic field is solved by an efficient iteration process in Fourier space. The computations show that the propagation direction of nanocracks can be effectively controlled via pre-patterning.