In situ deformation of micro-objects as a tool to uncover the micro-mechanisms of the brittle-to-ductile transition in semiconductors: the case of indium antimonide

Abstract

At ambient temperature and pressure, most of the semiconductor materials are brittle: this is the case of the III–V compound semiconductor indium antimonide, InSb. To study the role of dislocation nucleation at the onset of brittle-to-ductile transition, InSb micro-pillars have been fabricated by focused ion beam and in situ compressed at room temperature in a scanning electron microscope, in order to correlate the observation of slip traces at the pillar surface and features of the stress–strain curve. Transmission electron microscopy (TEM) thin foils have been cut out of the pillars to study the deformation microstructure. The TEM study of dislocations and the observation of slip traces at surfaces show that increasing the surface-to-volume ratio of the pillars modifies the dislocation nucleation conditions and favors plasticity even at room temperature. The role of dislocation nucleation from free surfaces is thus discussed within the larger context of the micro-pillar compression technique and extrinsic size effects.

Keywords:

• semiconductors
• micro-pillars
• compression
• plasticity
• dislocations
• brittle-to-ductile transition