Role of silicon vacancies in formation of Schottky barriers at Ag and Au contacts to 3C-and 6H-SiC

Abstract

A modified Ludeke model assuming that interfacial defect states are responsible for the formation of the Schottky barrier is applied to calculate the barrier heights Φbn in the systems 〈Ag, Au〉-〈3C-, 6H-SiC〉. Excellent agreement with experimental data is obtained. The calculation also shows that the concentration of silicon vacancies determining the Φbn value depends only slightly on the nature of the metal constituent of the contact.