Mechanical-stressing measurements of formation energy of single Shockley stacking faults in 4H-SiC

Abstract

Abstract The formation energy γ ISSF eq . of single Shockley stacking faults (1SSFs) in thermo-equilibrium is crucial for validating the anomalous expansion mechanism of 1SSF induced by forward current injection in 4H-SiC bipolar devices. As a function of variable mechanical stress externally applied to a plate sample of 4H-SiC, we systematically measured the ultraviolet intensity thresholds demarcating photo-induced expansion and contraction of 1SSFs. The experimental results on two types of 1SSF differing in the Schmid factor of mobile partial dislocations achieving 1SSF expansion/contraction showed a γ ISSF eq . value of 4.7 ± 1.6 mJ m−2, significantly smaller than the reported value of 14 ± 2.5 mJ m−2 obtained by transmission electron microscopic measurements.