Low-Temperature Growth of High-Quality SiC Single Crystals via TSSG from Si–Nd–C Melt: Multiphysics Simulation and Experimental Validation

The top-seeded solution growth (TSSG) method is a promising technique for growing high-quality silicon carbide (SiC) single crystals. However, the inherently low carbon solubility in the Si–C system limits its growth efficiency. In this study, neodymium (Nd) was introduced as a solvent additive to enhance carbon solubility and enable the efficient low-temperature growth of SiC single crystals at 1823 K. A 2D axisymmetric numerical model based on CGSim was developed to investigate heat conduction, convection, mass transport, and interfacial reactions. The effects of varying Nd concentrations on the temperature field, melt flow structure, carbon transport pathways, and supersaturation distribution were systematically analyzed. Experimentally, SiC single crystals were successfully grown at 1823 K using induction heating TSSG, and their morphology, orientation, and quality were characterized via SEM and EBSD. The experimental results were in good agreement with the simulations. This work is the first to demonstrate the growth of high-quality SiC single crystals from a Si–Nd–C solution at 1823 K. The results confirm that the addition of Nd significantly increases carbon solubility in the melt, facilitates effective carbon transport and uniform deposition, and thus promotes controlled crystal growth under low-temperature conditions. Furthermore, the optimal Nd concentration range for SiC single-crystal growth was identified as 15–25 mol %. Among them, 15 mol % Nd is favorable for achieving stable and uniform high-quality crystals, while 25 mol % Nd provides an efficient solution environment for rapid crystal growth.