In this study, Schottky barrier diodes were fabricated on a 0.5-inch single-crystalline diamond wafer, and the quality of the wafer as well as the performance of the devices were characterized. A rocking curve map indicated that the FWHM of the central 8 x 8-mm region was 10-50 arc sec, which is similar to that of high-quality HPHT single-crystalline diamond. The fabricated pVSBDs on the p(-)/p(+) stacked layer showed a high operation limit for the electrical field, with the mean value of this limit being higher than 2.5 MV/cm when the electrode was smaller than 300 pm. The performance of the devices seemed to be associated with the quality of the wafer. This indicates that the leakage current of a device is determined by the quality of the diamond wafer on which it is fabricated. (C) 2009 Elsevier B.V. All rights reserved.