We compare two extraction methods based on the Y-function technique to extract the massive (>100 k Omega) series resistance observed in SOI-MOSFET devices. A part the application of these methods for such high series resistance, the novelty in this paper is that our methods are based on the I-DS - V-GS characteristics measured for several drain voltages in the linear domain, while the classic methods are based on characteristics measured for several channel length. Here, we compare two types of SOI-MOSFET devices: Ultra-Thin Body (UTB) and Nano-Scale Body (NSB) sharing same W/L ratio but having a channel thickness of 46 nm and 1.6 nm, respectively. These devices were fabricated simultaneously on the same silicon wafer using a selective "gate recessed" process. Their respective current voltage characteristics measured at room temperature were found to be different by several orders of magnitude. In this paper, we show that, by using two kinds of Y-function based methods, the I-DS - V-GS characteristics of NSB can be analytically modeled by a massive series resistance depending on the gate voltage. (C) 2013 Elsevier Ltd. All rights reserved.