Current-voltage characteristic of Ti-pSi metal-oxide-semiconductor diodes

Abstract

The electrical characteristics of Ti‐pSi metal‐oxide‐semiconductor diodes have been studied as a function of temperature and of applied voltage, using conventional Schottky barrier capacitance‐voltage (C‐V) and current‐voltage (I‐V) measurements. The results show a strong deviation from those expected from thermionic emission and from the minority carrier injection theory for the current mechanism. Unlike other authors who proposed a multistep recombination‐tunneling mechanism, we have stressed that a model based on the inhomogeneity of the barrier height over the diode area predicts a temperature and voltage behavior of the I‐V characteristic similar to the recombination‐tunneling mechanism. The concept of inhomogeneity proposed by former authors is supported by Auger depth concentration profiles which show an intermixed region of Ti and Si. It is observed that the equilibrium semiconductor band bending exhibits a stronger temperature dependence than expected from the variation of the semiconductor Fermi level.