Comment on "negative capacitance at metal-semiconductor interfaces" [J. Appl. Phys. 68, 2845 (1990)]

Abstract

Recently, Wu, Yang, and Evans [J. Appl. Phys. 68, 2845 (1990)] ascribed excess negative and positive capacitances at abrupt Schottky diodes to interface charges and a "waterfall" of electrons "falling off the Schottky barrier cliff." This comment points out that such strange admittances are not related to interface charge at the front Schottky contact but to defective back contacts, as previously demonstrated [Phys. Rev. Lett. 60, 53 (1988) and Mater. Res. Soc. Symp. Proc. 91, 433 (1987)].