In this paper, a simple macro model of n-channel MOSFET with dual workfunction gate (DWFG) structure is proposed. The DWFG MOSFET has higher transconductance and lower drain conductance than conventional MOSFET. Thus analog circuit design using the DWFG MOSFET can improve circuit characteristics. Currently, device models of the DWFG MOSFET are insufficient, so simple series connected two MOSFET model is proposed. In addition, a two stage operational amplifier using the proposed DWFG MOSFET macro model is designed to verify the model.

In this paper, TCAD assessment of 30 V class n channel EDMOS (extended drain metal-oxide-semiconductor) transistors with DWFG (dual work function gate) structure are described, Gate of the DWFG EDMOS transistor is composed of both p- and n-type doped region on source and drain side. Additionally, lengths of p- and n-type doped gate region are varied while keeping physical channel length. Two-dimensional device structures are generated trough TSUPREM-4 and their electrical characteristics are investigated with MEDICI. The DWFG EDMOS transistor shows improved electrical characteristics than conventional device i.e. higher transconductance (gm), better drain output current (ION), reduced specific on-resistances (R0N) and higher breakdown characteristics (BVDss).