Physics / mechanism
Silicon carbide (SiC) is a wide-bandgap (WBG) semiconductor: bandgap 3.26 eV (4H polytype), breakdown field ~3 MV/cm, thermal conductivity ~490 W/m·K — roughly 3× silicon on all three figures. These properties enable power devices that switch faster, run hotter, and waste less energy than Si equivalents. Key device types: MOSFETs and Schottky barrier diodes (SBDs) rated 650 V–3.3 kV. State of the art: 200 mm wafer production ramping (Wolfspeed, Coherent, SICC), on-resistance figures approaching theoretical limits, defect density (micropipes, basal plane dislocations) still the primary yield lever. Dominant application: EV inverters, where SiC cuts switching losses ~50% vs Si IGBT.
Competitive landscape
GaN-on-Si competes directly below 900 V — lower substrate cost, higher switching frequency, but inferior at high-voltage/high-temperature. Si IGBTs remain entrenched in cost-sensitive, lower-frequency applications. GaAs and InP are irrelevant here. Diamond is a longer-horizon competitor with superior theoretical properties but no manufacturable substrate ecosystem. The real competitive axis is SiC vs GaN segmentation by voltage class and thermal budget.
| SiC | GaN-on-Si | Si IGBT | |
|---|---|---|---|
| Voltage sweet spot | 900 V–3.3 kV | 100–650 V | 600 V–6.5 kV |
| Switching freq | 10–100 kHz | 100 kHz–10 MHz | 1–20 kHz |
| Substrate maturity | 150/200 mm | 6–8” (on Si) | Commodity |
Companies using
Connected ideas
Sources
Frontier (open questions)
- To be added.