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 200–380K. Titanium dioxide (TiO2) thin film was deposited on a polycrystalline n-type Silicon (Si) substrate using the DC magnetron sputtering system at 200°C. In order to improve the crystal quality deposited film was annealed at 900°C in air atmosphere for phase transition from amorphous to rutile phase. The barrier height (Φb) and ideality factor (n) were calculated from I–V characteristics. An increase in the value of Φb and a decrease in n with increasing temperature were observed. The values of Φb and n for Au/TiO2(rutile)/n-Si SBDs ranged from 0.57eV and 3.50 (at 200K) to 0.82eV and 1.90 (at 380K), respectively. In addition, series resistance (Rs) and Φb 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 Rs values exhibit an unusual behavior that it increases with increasing temperature.