Revisiting MOSFET threshold voltage extraction methods

This article presents an up-to-date review of the several extraction methods commonly used to determine the value of the threshold voltage of MOSFETs. It includes the different methods that extract this quantity from the drain current versus gate voltage transfer characteristics measured under linear operation conditions for crystalline and non-crystalline MOSFETs. The various methods presented for the linear region are adapted to the saturation region and tested as a function of drain voltage whenever possible. The implementation of the extraction methods is discussed and tested by applying them to real state-of-the-art devices in order to compare their performance. The validity of the different methods with respect to the presence of parasitic series resistance is also evaluated using 2-D simulations.