In this paper an extended drain-current conductance method is introduced, which can be used for extraction of separated drain and source resistors, forward and reversed modes carrier mobilities and effective channel length of MOSFET. The new single device extraction method is successfully applied to logic devices with symmetric doping profiles and DRAM array devices with highly asymmetric doping profiles. Furthermore a new physical definition is introduced for effective channel length which provides a better understanding of the device. (C) 2009 Published by Elsevier Ltd.