Anisotropic Crystallization Growth of 4H-SiC: Insights from Molecular Dynamics

Silicon carbide (SiC) exhibits outstanding physical and chemical properties, making it highly promising for applications in power electronics and high-temperature sensors. Among its polytypes, 4H-SiC has attracted significant attention due to its superior electrical properties and high thermal conductivity. However, structural defects arising during the growth of SiC crystals hinder their practical application, and the conventional physical vapor transport (PVT) method lacks effective in situ monitoring capabilities. In this study, molecular dynamics (MD) simulations were conducted using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) to model the solid-liquid growth of 4H-SiC with various crystal orientations under the NPT ensemble. The effect of temperature on crystallization was analyzed, and 1900 K was determined to be the optimal simulation temperature. The impact of crystal orientation on crystallization quality and defect distribution was systematically investigated by analyzing the radial distribution function, growth rate, morphology, and defect characteristics. The results indicate that the F1 and F2 orientations exhibit high crystallization efficiency and low defect densities. In contrast, the F3 and F4 orientations exhibit higher defect concentrations, although some self-healing behavior is observed. These findings provide theoretical guidance for optimizing 4H-SiC synthesis and improving its performance, thereby facilitating the broader application of high-quality SiC crystals in next-generation electronic devices.