• Chinese 8-inch 4H-SiC substrate yields average 35-45% usable area due to micropipe densities of 0.3-0.5 cm^-2, versus 60% for Wolfspeed's 6-inch, delaying cost parity.
• Domestic epitaxy (Naura, CETC) achieves 85-90% BPD-to-TED conversion, below the >95% threshold needed to prevent bipolar degradation in 1,200V+ MOSFETs.
• Beta-Ga2O3's Baliga figure of merit is 3x SiC, but its thermal conductivity (0.23 W/m·K) forces 3x die area for 10kV switches, negating cost advantages.
• An 8-inch SiC fab requires $800M+ CAPEX for 100k wafers/year; Ga2O3 could cut substrate cost by 80%, but no commercial 4-inch substrates exist yet.
• China's equipment push (Naura, CETC) is closing the gap in epitaxy and ion implantation, but crystal growth remains the bottleneck, with 6-inch SiC still dominant.