The observation of negative transconductance effect caused by real-space-transfer of electrons in metal oxide semiconductor field effect transistors fabricated with Ta/sub 2/O/sub 5/ gate dielectric

Abstract

N-channel metal oxide semiconductor field effect transistors (MOSFETs) with Ta/sub 2/O/sub 5/ gate dielectric were fabricated. An intrinsic Ta/sub 2/O/sub 5//silicon barrier height of 0.51 eV was extracted from the gate current. The effective Ta/sub 2/O/sub 5//silicon barrier height including image force barrier lowering is about 0.37 eV with drain to source voltage V/sub DS/ ranging from 1.5 V to 4.0 V. Due to the low barrier height, negative transconductance effect was observed in the linear region. The decrease of drain current is due to the real space transfer of electrons from the drain terminal to the gate electrode.