Studies of barrier height mechanisms in metal–silicon nitride–silicon Schottky barrier diodes

In this paper we present a complete experimental study and theoretical treatment of the barrier height of metal–silicon nitride–silicon Schottky barrier diodes. This study avoids the ambiguities of previous investigations of metal–insulator semiconductor Schottky barriers by use of a more complete and more exact model and a wider range of experimental conditions. The barrier height of these diodes was measured as a function of nitride thickness for a variety of contact metals. From this data the effects of interface traps, fixed charge defects and band lineups can be distinguished from each other and the role that each of these mechanisms plays in determining the barrier height can be ascertained. The barrier height vs metal and barrier height vs thickness data show no signs of the effects of interface traps. Instead, the differences in barrier height observed depend solely on the band lineup at the metal–nitride interface, and fixed charge defects.