High breakdown voltage with low on-state resistance of p-InGaN/n-GaN vertical conducting diodes on n-GaN substrates

p-InGaN/n-GaN vertical conducting diodes were grown on freestanding n-GaN substrates by metal organic vapor phase epitaxy. The homoepitaxial growth produced a high-quality GaN layer, as evidenced by the full width at half maximum of the (0002) x-ray rocking curve is as low as 34 arc sec. For a diode with a 3.6-mu m-thick n-GaN layer, a high breakdown voltage (V-B) of 571 V is obtained with a low on-state resistance (R-on) of 1.23 m Omega cm(2), leading to the figure of merit, (V-B)(2)/R-on, of 265 MW/cm(2). This is the highest value among those previously reported for GaN-based vertical conducting Schottky and p-n junction diodes. (c) 2006 American Institute of Physics.