Fracture strength analysis of single-crystalline silicon cantilevers processed by focused ion beam

Abstract

The fracture strength properties of single-crystalline Si micro-components fully processed via focused ion beam were successfully evaluated by an in situ nano-mechanical testing system. Fracture initiation of all tested specimen was completely brittle within the detection limit of the testing system. By using different types of cantilever specimens (smooth/notched), it was suggested that the fracture initiation along the {111} plane was controlled primarily by the critical normal stress component regardless of the magnitude of shear stress component. The average strength value for FIB-processed specimens (σc=8.1GPa) was found to be approximately the same as that of wet-etch-processed specimens while larger than that of dry-etch-processed specimens.