Silicon → SiC → III-N.
Superjunction is a structural concept that can interact with different semiconductor materials. Material choice changes electric-field limits, mobility, thermal conductivity, processing, cost and the practical voltage/frequency envelope.
Silicon
The mature home of commercial high-voltage SJ MOSFETs. Excellent manufacturing ecosystem and cost position make it highly relevant for 500–800 V-class conversion.
Examples: CoolMOS, MDmesh, DTMOS, ROHM SJ families.
Silicon carbide
Wide bandgap and high critical electric field enable thinner high-voltage drift regions. SJ structures are being explored to push conductivity further within SiC.
Research example: Fuji Electric has published work on 1.2 kV SiC SJ MOSFETs.
Polarization engineering
III-nitride heterostructures can exploit spontaneous and piezoelectric polarization. Emerging work explores intrinsic charge balancing for superjunction-like structures.
What changes when the material changes?
No material wins every metric. System architecture, frequency, voltage, thermal path, packaging and economics determine the right choice.
| Dimension | Silicon SJ | SiC SJ / SiC | III-N / polarization SJ |
|---|---|---|---|
| Manufacturing maturity | Very high | High for mainstream SiC, SJ variants emerging | Emerging for SJ concept |
| High-voltage potential | Strong at mainstream conversion voltages | Very strong | Strong research potential |
| Thermal conductivity | Moderate | High | Depends on stack/substrate |
| Cost position | Generally favorable | Higher | Process-dependent |
| Switching frequency | Strong when optimized | Strong | Potentially very strong |
Research source: Fuji Electric SiC superjunction research ↗