Effect of Al doping on the natural growth direction of 6H-SiC crystals: From the DFT Calculation to Experiment

To achieve the regulation of 6H-SiC crystal morphology at low temperatures in the Acheson process, this study investigates the growth direction evolution of 6H-SiC by altering the surface energy differences between crystal planes through Al doping, using a combination of density functional theory (DFT) calculations and experimental methods. DFT results indicate that Al doping exerts differential effects on the surface energies of 6H-SiC crystal planes via electron distribution adjustment and chemical bond reconstruction, thereby influencing the growth direction of 6H-SiC. This mechanism provides a theoretical basis for controlling crystal growth direction through doping. Experimental results demonstrate that Al doping alters the natural growth direction of 6H-SiC from the <10-10> direction to gradient growth along the <0001> direction.