Solution growth of silicon carbide using unary chromium solvent

Abstract

Solution growth of silicon carbide (SiC) using unary chromium (Cr) solvent was studied because the system enables a high solubility difference and a low degree of supersaturation, which would lead to rapid growth with a stabilized growth interface. The liquidus composition at SiC saturation in a quasi-binary Cr–SiC system was studied at 1823–2173K. The measured carbon (C) contents are in good agreement with the thermodynamic evaluation using the sub-regular solution model. In addition, growth experiments using a unary Cr solvent were performed by the bottom-seeded travelling solvent method. The obtained growth rates at 1803–1923K with a temperature difference of 15–70K were proportional to the solubility difference between the seed and source temperatures, indicating that the growth was controlled by the mass transfer of C in the solution. The maximum growth rate of 720µm/h at 1803K was much higher than the growth rate by Si-rich solvents, suggesting that the Cr-rich solvent is suitable for the rapid growth at a low temperature.