Threshold voltage extraction methods for MOS transistors

Abstract

The threshold voltage of the MOS transistor is a very important parameter used in all circuit simulation programs. The aim of this paper is to compare several largely applied threshold voltage extraction methods used both for long channel and short channel MOSFETs. This methods use either the linear operation region or the saturation operation region of the transistors. The new derivative extraction method proposed in this paper doesn't depend on the operation region for long channel devices and gives comparable results for short channel devices. It is a very simple and accurate extraction method. The experimental data used in the paper were measured using a HP4155B system. The mathematical calculation and the threshold voltage extraction are performed using MATHCAD designed programs.