Thermomigration of molten Cr-Si-C alloy in 4H-SiC at 1873–2273 K

The effect of Al addition to a Cr solvent without molten Si on the surface morphology in a solution growth of SiC

“…The behavior of the growth surface is believed to be affected by many growth parameters, such as supersaturation of the solute and the surface energy. 6,[10][11][12][13][14]16,30,37,38) The supersaturation in the vicinity of the seed crystal is related to the temperature and flow distribution in the solvent. As shown by Eq.…”

“…There are many relationships that may be used to predict the viscosity of a multicomponent system using thermodynamic parameters. 20,[24][25][26][27][28][29][30][31] Those formulas that incorporate both viscosity and surface energy were employed in this work, because the present study involved both liquid Cr metal and Cr-Al alloys. The relationship between the viscosity (h) of a pure liquid metal and temperature was examined by Zhang et al, 20) who reported an Arrhenius equation incorporating a pre-exponential term ( ) h 0 and activation energy (E), written as:…”

“…This equation demonstrates that the viscosity of the metal decreases with increasing temperature. Kawanishi et al 30) established that the viscosity of a liquid alloy can be described as:…”

Review of solution growth techniques for 4H-SiC single crystal

“…Although helium (He) is more expensive than argon, it is favored by many scholars due to its lower viscosity and higher thermal conductivity (8 times of argon) [85] . The migration rate and Cr content in 4H-SiC are similar under He and Ar atmosphere, it is proved that growth under He results in a higher growth rate than growth under Ar owing to the larger heat dissipation of the seed holder [68] . He impedes the voids formation inside the grown crystal and spontaneous nucleation in the solution, then, a smooth surface morphology can be obtained [86] .…”

“…The heat dissipation was adjusted through the shaft and thermal flow through the crystal by changing the thickness of rigid insulation inside the hollow graphite holder, which reduced the lateral temperature gradient at the SiC-solution interface [Fig. 18(f)] [42,68] . The hollow graphite rod was used to create a single crystal with a full-flat surface at a seed rotation rate of 60 rpm in Si-Ti solvent via ACRT.…”