The Cu Based AlGaN/GaN Schottky Barrier Diode

The electrical characteristics of Cu and Ni/Al AlGaN/GaN Schottky barrier diodes on Si substrates are compared. The onset voltage of Cu Schottky diodes is about 0.4 V less than the Ni/Al contact. For the Cu/Ni Schottky contact, the leakage current is 4.7×10^-7 A/mm at -10 V. After annealing, the leakage current is decreased to 3.7×10^-7 A/mm for 400°C or 4.6×10^-8 A/mm for 500°C, respectively. The electrical property is affected by the thickness ratio of Cu to Ni. The Cu/Ni for 80/20 nm shows a low onset voltage, while the Cu/Ni for 20/80 nm shows a low leakage current. Both breakdown voltages are above 720 V.