Research Article
On the Evaluation of Gate Dielectrics for 4H-SiC Based Power MOSFETs
Table 1
List of physical properties of various dielectric materials reported in the literature.
| | Material | Dielectric
constant () | Bandgap
(eV) | (eV)
with respect to Si | (eV)
with respect to 4H-SiC | Structure | Preparation method |
| | SiO2 | 3.9 | 8.9 | 3.2 | 2.2–2.7 | Amorphous | Thermal, PECVD | | Si3N4 | 7.0 | 5.1 | 2.0 | — | Amorphous | Thermal, LPCVD, MOCVD | | SiON | 4.0–7.0 | 5.0–9.0
(O/N ratio) | 2.8 | — | Amorphous | Thermal, PECVD | | Al2O3 | 9.0 | 8.7 | 2.8 | 1.7 | Amorphous | Sputtering,
ALCVD | | HfO2 | 25 | 5.7 | 1.5–1.7 | 0.54 and 0.7–1.6 |
Mono, tetra, cubic | Sputtering,
ALCVD | | ZrO2 | 25 | 7.8 | 1.4 | 1.6 | Mono, tetra, cubic | ALCVD | | Ta2O5 | 26 | 4.5 | 1–1.5 | — | Orthorhombic | MOCVD | | Y2O3 | 15.0 | 5.6 | 2.3 | — | Cubic | — | | La2O3 | 30 | 4.3 | 2.3 | — | Cubic | — | | AlN | 9.14 | 6.2 | 2.2 | 1.7 | Wurtzite | MOCVD |
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