A promising Si–Cr–Nd–C solution system designed for rapid growth of 3C-SiC at a low temperature of 1873 K

Abstract

As 3C-SiC can transform to other polytypes when the temperature is ≥2073 K, the current physical vapor transport (PVT) method can hardly grow wafer-grade 3C-SiC because its growth temperature is normally ≥2473 K. Therefore, solution growth is considered the most promising approach for the growth of wafer-grade 3C-SiC. However, few solution systems are available for growing 3C-SiC, which possess acceptable C solubilities and facilitate growth rate at growth temperatures below 2073 K. To address this challenge, this study designed a new Si–Cr–Nd–C solution that shows promise for the rapid growth of 3C-SiC at 1873 K, which is a significantly lower growth temperature than that required by most solution systems and the PVT method. The average C solubility in the SiC saturated Si-(40-x) mol% Cr-x mol% Nd alloy melts increased by 49.6 and 58.5 times at 1823 K and 1923 K, respectively, compared to the conventional Si-40 mol% Cr alloy melt without Nd. Notably, this study showed that the polytype of grown SiC crystal could transform from 4H-SiC to 100% 3C-SiC by adjusting the Nd content in the Si-(40-x) Cr-x Nd alloy melts, and the average growth rate of the SiC crystal at 1873 K was enhanced by 2.2 times by increasing the Nd content from 0 mol% to 20 mol%. Finally, rapid growth of the 3C-SiC single crystal is expected if the nucleation and growth of 3C-SiC with a single orientation can be controlled.