Accurate Gate Impedance Determination on Ultraleaky MOSFETs by Fitting to a Three-Lumped-Parameter Model atFrequencies From DC to RF

Abstract

We present an experimental methodology that demonstrates the suitability of the conventional three-lumped- parameter model for gate impedance of MOSFET devices at frequencies from dc to the gigahertz range, which permits accurate extraction of model parameters. The parasitic effects at a high frequency are minimized by using radio frequency techniques (i.e., short return paths and de-embedding structures), whereas a robust parameter extraction algorithm overcomes possible instrument inaccuracies. When combined, these allow simultaneous extraction of all three parameters (i.e., Cgate, RDT and Rseries) from the model. The technique is applied to conventional SiO2 -based MOSFET devices and to ultraleaky HfO2 devices with aggressively scaled gate dielectric thickness.