Numerical Analysis of Dislocation Density of SiC Crystals Tilted from [0001] Toward [12 over bar 10]$[ {1\bar 210} ]$ and [11 over bar 00]$[ {1\bar 100} ]$ Grown by Physical Vapor Transport

A 3D and time-dependent analysis of dislocation density using the Alexander-Haasen model to estimate the plastic deformation of tilted angle growth of 4H-SiC single crystals during crystal growth and cooling processes grown using the physical vapor transport method is performed. The growth direction is set to tilt from [0001] toward[12 over bar 10]$[ {1\bar 210} ]$ and [11 over bar 00]$[ {1\bar 100} ]$ to fabricate wafers to stabilize polytype during crystal growth of the epitaxial layer. The maximum dislocation density in SiC crystals increases as the tilted angle increases, whereas von Mises stress, which is one of the measures of dislocation density, decreases. The calculated results show dislocation density distribution in the crystal grown in [0001] exhibits six-folded symmetry, whereas that in the crystal grown in the tilt direction from [0001] toward [12 over bar 10]$[ {1\bar 210} ]$ and [11 over bar 00]$[ {1\bar 100} ]$ exhibits asymmetric distribution.