Interface trap density estimation in FinFETs from the subthreshold current

In this work we present a measurement approach to determine the interface trap density in FinFETs as a function of their energy. It is based on the precise determination of the gate voltage dependent ideality factor of the subthreshold current in this device. The required measurement accuracy for temperature, drain current and transconductance is derived, and we propose an implementation for wafer-level device measurement on contemporary test set-ups. Exemplary interface trap distributions are shown as obtained from two FinFET device technologies, featuring the commonly observed bathtub shape.