Semiconductor device including a field effect transistor and a passive capacitor having reduced leakage current and an improved capacitance per unit area

Abstract

A semiconductor device comprises a field effect transistor and a passive capacitor, wherein the dielectric layer of the capacitor is comprised of a high-k material, whereas the gate insulation layer of the field effect transistor is formed of an ultra thin oxide layer or oxynitride layer so as to provide for superior carrier mobility at the interface between the gate insulation layer and the underlying channel region. Since carrier mobility in the capacitor is not of great importance, the high-k material allows the provision of high capacitance per unit area while featuring a thickness sufficient to effectively reduce leakage current.