Eliciting stable nanoscale fracture in single-crystal silicon

In this letter, we demonstrated stable nanoscale fracture in single-crystal silicon using an in-situ wedge-loaded double cantilever beam (DCB) specimen. The fracture toughness K (IC) was calculated directly from instrumented measurement of force and displacement via finite element analysis with frictional corrections. Measurements on multiple test specimens were used to show K (IC )= 0.72 +/- 0.07 MPa m(1/2) on {111} planes and observe the crack-growth resistance curve in <500 nm increments. The exquisite stability of crack growth, instrumented measurement of material response, and direct visual access to observe nanoscale fracture processes in an ideally brittle material differentiate this approach from prior DCB methods. IMPACT STATEMENT In-situ fracture toughness experiments on single-crystal silicon revealed stable nanoscale fracture and identified the shape of the crack-growth resistance curve, role of fabrication-induced artifacts, and origin of fracture surface features.