The effect of shear on nucleation and movement of basal plane dislocations in 4H-SiC

Basal plane dislocations (BPDs) are a key factor influencing the advancement of the 4H-SiC semiconductor. In this paper, the effects of shear forces on the nucleation and movement of BPDs are revealed by employing molecular dynamics simulations. The stress-strain curves of 4H-SiC subjected to different shear forces at different temperatures are obtained. It is found that the decrease in mechanical properties of 4H-SiC is mainly due to the occurrence of dislocation. This study also delves into the complexities of dislocation entanglement and slip, unraveling the impact on the mechanical properties of 4H-SiC. Moreover, the causes of dislocation within the crystal lattice were clarified from a microscopic atomic vantage point, shedding light on the intricate mechanisms involving chemical bond rupture and regeneration. These findings not only enrich our understanding of BPDs nucleation but also provide invaluable insights for mitigating BPDs in 4H-SiC.