Extreme Bandgap Al_0.63Ga_0.37N Quasivertical Schottky Barrier Diodes with a High Baliga Figure of Merit of 630 MW cm⁻²

"Extreme bandgap n-Al0.63Ga0.37N quasi-vertical Schottky barrier diodes (SBDs) with doping densities of ≈8 × 1017 cm−3 (Sample A) and ≈2 × 1017 cm−3 (Sample B) are grown on an AlN/sapphire substrate using metalorganic-chemical vapor deposition (MOCVD). Sample A achieves a high forward current density of ≈59.5 kA cm−2 at 10 V with an ION/IOFF ratio of ≈108 (calculated from the forward current at + 3.8 V and the reverse current at −1 V) and an ideality factor of 2.8. Sample B has a forward current density of ≈6.25 kA cm−2 and a much better ideality factor of 1.9. For Sample B, a breakdown voltage of 389 V is measured, which translates into a breakdown field of ≈7.8 MV cm−1 and a Baliga figure of merit of 630 MW cm−2, which are the highest values ever reported for quasi-vertical Schottky barrier diodes with a similar AlxGa1−xN composition.