Bend Testing of Silicon Microcantilevers from 21A°C to 770A°C

The measurement of mechanical properties at the microscale is of interest across a wide range of engineering applications. Much recent work has demonstrated that micropillar compression can be used to measure changes in flow properties at temperatures up to 600A degrees C. In this work, we demonstrate that an alternative microscale bend testing geometry can be used to measure elastic, plastic, and fracture behavior up to 770A degrees C in silicon. We measure a Young's modulus value of 130 GPa at room temperature, which is seen to drop with increasing temperature to a parts per thousand 125 GPa. Below 500A degrees C, no failure is seen up to elastic strains of 3%. At 530A degrees C, the microcantilever fractures in a brittle fashion. At temperatures of 600A degrees C and above plastic deformation is seen before brittle fracture. The yield stresses at these temperatures are in good agreement with literature values measured using micropillar compression.