Dislocation-mediated plasticity in silicon during nanometric cutting : a molecular dynamics simulation study materials science in semiconductor processing

摘要

The nucleation and propagation of dislocations and its consequence on the defect structure in silicon during nanometric cutting are not well known, although the amorphization and high pressure phase transformation studies on silicon have remained at the epicentre of research across various disparate disciplines for over a decade. This paper proposes a new mechanism of crystal plasticity identified by a fully automated dislocation extraction algorithm in molecular dynamics simulations of nanometric cutting of silicon for different cutting planes/directions at a wide range of temperatures (300 K-1500 K). Alongside amorphization of silicon, our simulations revealed nanoscale stochastic nucleation of dislocations and stacking faults, which serve as mediators of microscopic plasticity during various contact loading operations and manufacturing processes of silicon. Of interest is that, irrespective of the cutting temperature, the stacking faults, which were not formed for both the (010)[100] and (111)[1 ̅10] crystal setups, were generated with three atomic layers in the (110)[001 ̅] cutting.