Stability of multiple Shockley type basal plane stacking faults in heavily nitrogen-doped 4H-SiC crystals

•The stability of multiple SSFs in heavily N-doped 4H-SiC crystals was investigated.•The calculated energy levels in SSFs were compared with the experimental results.•The formation energies of SSFs were also calculated based on the ANNNI model.•Based on these results, the stability of multiple SSFs was discussed.•SSSFs except 2SF(6,2) are not formed during growth of heavily N-doped 4H-SiC. The stability of various types of multiple Shockley type basal plane stacking fault in heavily nitrogen-doped 4H-SiC crystals was theoretically investigated on the basis of the quantum well action (QWA) mechanism. The energy levels of confined electrons within multiple Shockley stacking faults (SSFs) were calculated using the simple quantum well model and compared to the experimental values estimated from photoluminescence measurements. The formation energies of the stacking faults were also calculated on the basis of the axial next nearest neighbor Ising (ANNNI) model for SiC polytypes. Based on these physical and electronic parameters, the stability of multiple SSFs in heavily nitrogen-doped 4H-SiC crystals was discussed, and it was revealed that the stacking sequence of multiple SSFs largely affects their stability; SSFs having a cubic stacking sequence of medium thickness (five to six Si-C bilayer thickness) are stable in heavily nitrogen-doped 4H-SiC crystals at the typical growth and device processing temperatures of SiC, i.e., 1500–2600 K.