Reconstruction of physical-vapor-transport SiC growth setup for large crystal height

Reducing SiC wafer cost requires higher usable crystal height and material yield. We reconstruct a single-coil RF-heated PVT-SiC setup using low-cost graphite changes: (i) thermally equalizing insulation from multilayer expanded-graphite sheets and (ii) bottom spacing via a cylindrical spacer. In a 168-h run, we achieved ~70 mm height with nominal/substantial yields 80.9%/87.0% vs. 19.5%/38.2% and reduced gas leakage from 27.2% to 4.1%. Simulations identified ΔTsource (axial source-temperature span) as governing; reducing it increases the initial growth rate, independent of configuration. This offers a practical, scalable route to higher PVT-SiC throughput without reactor remodeling or costly components on existing lines.