Negative transconductance effect in metal oxide semiconductor field effect transistors fabricated with Ta2O5 gate dielectric

N-channel metal oxide semiconductor field effect transistors with Ta₂O₅ gate dielectric were fabricated. An intrinsic Ta₂O₅/silicon barrier height of 0.51 eV was extracted from the gate current. The effective Ta₂O₅ /silicon barrier height including image force barrier lowering is about 0.37 eV with drain to source voltage V_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