We fabricated a Schottky barrier diode (SBD) on ion-implanted diamond substrates. The SBDs contained lightly doped regions under the Schottky electrodes and heavily doped regions beneath the Ohmic contacts. The current remained below 6.4 × 10−11 A at reverse biases of up to 10 V, but increased sharply at a forward bias of −3.5 V. The Schottky barrier height and ideality factor under forward bias were estimated to be 1.1 eV and 10, respectively. The hole concentrations obtained by measuring the capacitance at various supplied voltages were in good agreement with the values obtained from the Hall effect measurements.

In this study, we fabricated p-type diamond Schottky barrier diodes, and performed selective B doping for the p-type channel and Ohmic region by double ion implantation. Schottky barrier diodes were redesigned the configuration and the shape of Ohmic and Schottky electrodes to improve device characteristics. The fabricated device exhibited a rectification ratio of approximately 2400 because of decreasing the parasitic resistance to 2.7 × 107 Ω and the ideality factor to 2.7. The Schottky barrier height was obtained to be 1.04 eV. It is indicated that the diamond Schottky barrier diode fabricated only by B ion implantation is improved by refinement of the electrode structure. The hole concentration was estimated to be 3.0 × 1017 cm−3 from the C-V measurements.