Characterization of capacitance-voltage features of Ni/diamond Schottky diodes on oxidized boron-doped homoepitaxial diamond film

The electrical properties of Ni/diamond Schottky diodes fabricated on oxidized boron-doped homoepitaxial diamond film have been studied in order to investigate the electrical behavior of diamond-based electronic devices. The current-voltage (I-V) characteristics of the Ni-Schottky contacts to the boron-doped homoepitaxial diamond film show excellent rectification properties. The capacitance-voltage (C-V) features of the Ni/diamond Schottky diodes were characterized in the frequency range from 10(-3) to 2X10(5) Hz. The C-V measurements indicate that the space charge density (N-t) and built-in potential (V-d) values are approximately 6.0X10(16) cm(-3) and 1.25 V, respectively, and show weak frequency dependence in the range from 10(-3) to 10(4) Hz. Capacitance-frequency measurement at zero bias indicated that the degrading capacitance at high frequency (>10(4) Hz) is primarily due to the high series resistance of the homoepitaxial diamond film. (C) 2003 Elsevier Science B.V. All rights reserved.