Various attempts have been made to evaluate the correct value (A*=146 A/cm2.K2) ofRichardson's constant. In 2005 S. Ferrero et al. published their research in which they performedan analysis of electrical characterizations of twenty Ti/4H-SiC(titanium on silicon carbide) Schottkydiodes with the help of thermionic emission theory and evaluated the value of Richardson's constantto be 17±8 A/cm2.K2; which is very low as compared to the theoretical value of 146 A/cm2.K2.Wehave tried in this paper to evaluate the Richardson's constant's value by nearly same experimental tech-niques followed by S. Ferrero et al. and additionally, have applied Tung's theoretical approach whichdeals with the incorrect value of A* in the perspective of Schottky barrier inhomogeneities caused bythe presence of nanometer size low barrier patches present in the uniform high barrier of the Schottkydiode.We have fabricated two Ti/4H-SiC (titanium on silicon carbide) Schottky diodes with differentareas and oneMo/4H-SiC (molybdenumon silicon carbide) Schottky diode. In this paper we have pre-sented a comparative analysis of forward current-voltage characteristics of all three Schottky diodes.In all three cases we were successful in the evaluation of nearly correct value of Richardson's constant.This work emphasizes the effects of differentmetal-SiC combinations and laboratory environments onthe evaluation of Richardson's constant and the effective area involved in the current transport. As pre-dicted by Tung's model the effective area is seen to be substantially different from the geometric areaof the Schottky diode. Evaluated values of A*, with an error of ±2, come out to be 145.39, 148.33and 148.33 A/cm2.K2for Ti/4H-SiC(large area), Mo/4H-SiC and Ti/4H-SiC(small area) Schottkydiodes, respectively.
Systematic study of interface trap and barrier inhomogeneities using I-V-T characteristics of Au/ZnO nanorods Schottky diode