Study of frequency dispersion of capacitance-voltage characteristics of boron-doped diamond Schottky diodes

Abstract

A single-crystal diamond doped with boron was studied in this work. For electrical measurements an array of Schottky contacts and a large Ohmic contact were fabricated. The capacitance-voltage (C-V) characteristics of the sample were obtained experimentally in wide temperature range and modeled. At high temperature (445 K) the slope of the C-V characteristics does not depend on the test signal frequency. The calculated concentration of free charge carriers is the same for all frequencies within the experimental error and approximately corresponds to the total boron concentration. At low temperatures (235 K), there is a significant difference in capacitances measured at different frequencies, the calculated concentration varies from 5·1017 cm-3 to 5·1015 cm-3 in the available frequency range. The reasons for the frequency dispersion of capacitance-voltage characteristics of boron-doped diamond diodes are discussed.