Modeling the Abnormal Behavior of the 6H-SiC Schottky Diode Using Lambert W Function

Abstract

Electrical study of Ni and Ti metals of Schottky contacts on n-6H-SiC epitaxial layers is performed, by current-voltage (I-V) characterization. Ni/6H-SiC shows inhomogeneous barrier height behavior. Thermionic emission model is coupled with the Lambert function to obtain an explicit form of the Schottky equation as well as to specify the number of branches necessary for modeling the abnormal behavior. The inhomogeneous barrier height for the investigated Ni/6H-SiC junction can be reproduced by a model that includes two Schottky branches, which give a low (L) and a high (H) Schottky barriers ( L bn   0.92 eV, H bn   1.56 eV), as well as give a low and a high ideality factors (n L  1.93, n H  1.23).