The temperature dependent analysis of Au/TiO2 (rutile)/n-Si (MIS) SBDs using current-voltage-temperature (I-V-T) characteristics

Abstract

In this study, the main electrical parameters of Au/TiO2(rutile)/n-Si Schottky barrier diodes (SBDs) were analyzed by using current-voltage-temperature (I-V-T) characteristics in the temperature range 200-380 K. Titanium dioxide (TiO2) thin film was deposited on a polycrystalline n-type Silicon (Si) substrate using the DC magnetron sputtering system at 200 degrees C. In order to improve the crystal quality deposited film was annealed at 900 degrees C in air atmosphere for phase transition from amorphous to rutile phase. The barrier height (Phi(b)) and ideality factor (n) were calculated from I-V characteristics. An increase in the value of Phi(b) and a decrease in n with increasing temperature were observed. The values of Phi(b) and n for Au/TiO2(rutile)/n-Si SBDs ranged from 0.57 eV and 3.50 (at 200 K) to 0.82 eV and 1.90 (at 380 K), respectively. In addition, series resistance (R-s) and Phi(b) values of MIS SBDs were determined by using Cheung's and Norde's functions. Cheung's plots are obtained from the donward concave curvature region in the forward bias semi-logarithmic I-V curves originated from series resistance. Norde's function is easily used to obtain series resistance as a function of temperature due to current counduction mechanism which is dominated by thermionic emission (TE). The obtained results have been compared with each other and experimental results show that R-s values exhibit an unusual behavior that it increases with increasing temperature. (C) 2012 Elsevier Ltd. All rights reserved.