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)

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 ( Φ 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 , Φ B , and series resistance were changed from 0.372 V, 0.665 eV, and 243.5 Ω at 10 kHz to 0.603 V, 0.896 eV, and 35.9 Ω 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.