Frequency effect on capacitance and conductance characteristics of Au/HfO2/p-Si Schottky diode prepared by RF sputtering method

Abstract

HfO₂ thin film was deposited on p type Si substrate by radio frequency sputtering method for the fabrication of Au/HfO₂/p-Si Schottky diode. The capacitance (C) and conductance (G) properties of the Au/HfO₂/p-Si diode were examined at various frequencies and voltages. The properties of the diode were investigated within the voltage range of (-3V) - (+3V) and frequency range of 1 kHz - 1 MHz. The characteristics of C and G against voltage of the diode were determined to be strongly dependent on bias frequency and voltage. The capacitance decreases significantly with increasing of the frequency, showing the existence of steady interface state density. The series resistance ( ) and interfacial state density ( ) distributions of the produced diode were tried to be clarified. The frequency dependency of the  and  were found using conductance and Hill–Coleman’s technique and it has been determined that the  and  decreases with increasing frequency from 997 Ω and 7.89 x10¹¹ eV^-1 cm^-2 for 1 kHz to 144 Ω and 2.49 x 10¹¹ eV^-1 cm^-2 for 1 MHz. The results of the study showed that the Au/HfO₂/p-Si structure fabricated by RF sputtering method can be used as a Schottky diode in electronic applications in a wide frequency range.