Semiconductor devices having selectively tensile stressed gate electrodes and methods of fabricating the same

Abstract

A semiconductor device includes an active region. A gate electrode is disposed on the active region. An isolation region adjoins the active region, and is recessed with respect to a top surface of the active region underlying the gate electrode. The isolation region may be recessed a depth substantially equal to a height of the gate electrode. In some embodiments, the gate electrode is configured to support current flow through the active region along a first direction, and a tensile stress layer covers the gate electrode and is configured to apply a tensile stress to the gate electrode along a second direction perpendicular to the first direction. The tensile stress layer may cover the recessed isolation region and portions of the active region between the isolation region and the gate electrode. In further embodiments, an interlayer insulating film is disposed on the tensile stress layer and is configured to apply a tensile stress to the gate electrode along the second direction.