Electrical characteristics of Ti-Si(100) interfaces

Abstract

The Schottky barrier height of titanium on both n-type and p-type Si(100) has been measured in the temperature range 85-355 K using a current-voltage technique. Auger electron spectroscopy and X-ray photoemission spectroscopy were used to characterize the silicon surfaces and to monitor the reaction between titanium and silicon. The results showed that only a few monolayers of SiO2 at the interface have a large effect on the barrier height and its temperature dependence, compared with that of silicide formation. The n-type and p-type barrier heights for both the metal on Si(100) surfaces with minimal surface oxide present and the reacted silicide phase were found to decrease with increasing temperature and with the same coefficient within the experimental error. This coefficient was found to be approximately equal to one-half the temperature coefficient of the indirect energy gap in silicon, consistent with the predictions of recent models of barrier formation based on Fermi level pinning in the center of the indirect band gap. © 1989.