The temperature, frequency and voltage dependent characteristics of Al-TiW-Pd2Si/n-Si structure using I-V and G/ω-V measurements

In this study it was investigated the behavior of forward and reverse bias current-voltage (I-V), capacitance-voltage (C-V) and conductance-voltage (G/ω-V) characteristics of Al-TiW-Pd2Si/n-Si Schottky diodes fabricated by the magnetron sputtering method. Experimental results show that ideality factor n and zero-bias Schottky barrier height are strong function of temperature. The forward characteristics (I-V) are analyzed on the basis of the standard thermionic emission model and the assumption of a Gaussian distribution of the barrier height. The values of Schottky barrier heights and zero-bias standard deviation have been calculated as 0.535 eV and 0.069 V, respectively. The interface states density profile in the band gap of semiconductor has been calculated. On the basis of (C-V) and ((G/ω-V) characteristics of Al-TiW-Pd2Si/n-Si structures over a wide frequency range of 5 kHz- 5 MHz series resistance distribution profile have been investigated. The C-V-f and G/ω-V-f characteristics of studied structures show fairly large frequency dispersion especially at low frequencies due to equilibrium with the semiconductor. Dielectric properties and electrical conductivity of Al-TiW-Pd2Si/n-Si structures in the frequency range of 5 kHz-10 MHz and voltage range from 4 V to 10 V have been investigated in detail by using experimental C-V and G/ω-V measurements. Experimental results indicate that the values of ε show a steep decrease with increasing frequency for each voltage. It can be concluded that the interfacial polarization can be more easily occurred at low frequencies and the majority of interface states at metal semiconductor interface, consequently contributes to derivation of dielectric properties of Al-TiW-Pd2Si/n-Si structures. The reason is explained in term of displacement of atoms at the fabrication of silicides and the presence of hexagonal emptiness in crystal lattice of Si