On the wide range frequency and voltage dependence of electrical features and density of surface states of the Al/(Cu:DLC)/p-Si/Au Schottky diodes (SDs)

Abstract

Due to their high dielectric strength, high resistivity, and extended range of band gap, diamond-like carbon films have great potential in the semiconductor device applications. In this study, Cu-doped diamond-like carbon (DLC) film deposited on Si substrate by electrodeposition technique to obtain Au/Cu-DLC/p-Si Schottky diodes (SDs). X-ray photoelectron spectroscopy was used to investigate the chemical compositions of the film. The (capacitance/conductance)-voltage-frequency (C-V-f, G-V-f) features of this structure were investigated between 1 kHz and 3 MHz. The basic electronic parameters of the SDs such as diffusion potential (V-D), Fermi energy (E-F) level, barrier height (phi(B)), and depletion layer (W-D) thickness were calculated from the reverse-bias C-2-V curves depending on frequency. The values of V-D, phi(B), and series resistance were changed from 0.372 V, 0.665 eV, and 243.5 omega at 10 kHz to 0.603 V, 0.896 eV, and 35.9 omega at 3 MHz, respectively. The voltage and frequency-dependent spectra of interface states and their life time were also obtained by both the parallel conductance and high-low-frequency capacitance methods, respectively. The obtained results confirm the potential usage of DLC film in electronic device, and fabricated device shows excellent dielectric properties.