<i>Ab initio</i> density functional theory calculation of stacking fault energy and stress in 3C‐SiC

Abstract

Abstract Stacking faults (SFs) in the cubic polytype of silicon carbide (3C‐SiC) can bring about the leakage current in devices or cause warping of wafers. Along with experimental efforts with the aim to reduce SFs in 3C‐SiC, theoretical approach is needed to reveal the mechanical aspects of SFs. In this study, we employ ab initio density functional theory calculations to investigate the fundamental mechanical properties of SFs in cubic SiC, including the effect of stress and doping atoms (substitution of C by N or Si). Stress and strain induced by SF formation is quantitatively evaluated. Calculation of SF energies indicates that extrinsic SFs are stable. The extrinsic SFs containing double and triple SiC layers are found to be slightly more stable than the single‐layer extrinsic SF, which supports experimental observations. Neglecting the effect of local strain induced by doping, nitrogen doping around an SF obviously increase the SF formation energy, while SFs seem to be easily formed in Si‐rich models. Effect of tensile or compressive stress on SF energies is found to be very small, suggesting stress condition (large compression) induced by substitution of C atoms by Si should not substantially change the formability of SFs.