Evaluation of electrical and thermal properties of single crystalline diamond with large area of $18\ \mathbf{mm}\times 18\ \mathbf{mm}$ for power module

Diamond substrate was evaluated from the viewpoint of voltage withstand and thermal performance. High voltage of up to 30 kV was successfully applied without electrical breakdown to thin substrate of 300 μm. Superior thermal performance of 0.95 K/W compared to conventional materials (silicon nitride and aluminum nitride) was also measured with a single-crystalline mosaic diamond substrate with large area of 18 mm×18 mm.