Accurate surface potential determination in Schottky diodes by the use of a correlated current and capacitance voltage measurements. Application to n-InP

Abstract

Based on current voltage (I—Vg) and capacitance voltage (C—Vg) measurements, a reliable procedure is proposed to determine the effective surface potential Vd(Vg) in Schottky diodes. In the framework of thermionic emission, our analysis includes both the effect of the series resistance and the ideality factor, even voltage dependent. This technique is applied to n-type indium phosphide (n-InP) Schottky diodes with and without an interfacial layer and allows us to provide an interpretation of the observed peak on the C—Vg measurements. The study clearly shows that the depletion width and the flat band barrier height deduced from C—Vg, which are important parameters directly related to the surface potential in the semiconductor, should be estimated within our approach to obtain more reliable information.