EFFECTS OF SCALING ON DOUBLE GATE MOSFET

Abstract

Scaling factor of semiconductor device is continually decreasing. But in MOSFET when scaling factor is scale down in such a way that channel length is decreased below to 100nm then short channel effect (SCE) is appeared. Below 100nm channel length Double Gate MOSFET (DG-MOSFET) is selected to suppress SCE. DG MOSFET is more relevant to further scale down. In against of MOSFET, DG-MOSFET has tremendous advantage when it is scale down. Since the potential distribution in double-gate MOSFET differs greatly from that in single gate MOSFET because of symmetrical device structure with quite low channel doping concentration, then the scaling theory developed for bulk MOSFET cannot be applied to double-gate MOSFET. In this thesis constant field scaling has been applied to DG MOSFET and then effects of scale down have been shown. To show effects analytically, firstly equations of electrons concentration, electric potential, electric field, threshold voltage, drain current and tranconductance are derived and modified for two dimensional, very low doped DG MOSFET and then influence of scaling down of channel thickness, channel length, oxide thickness and voltage have been analytically analyzed on these equations and DG MOSFET