Semiconductor device including gate electrode having damascene structure and method of fabricating the same

A gate electrode conductive layer is formed on an active region that is recessed relative to field oxide layers so as to define a damascene structure. The gate electrode conductive layer is formed on the active region but is not formed on a field region so that the thickness of an interlayer insulation layer deposited in a succeeding process is reduced, thereby reducing or preventing voids within the interlayer insulation layer. A polysilicon is formed on the bottom of the active region by selective epitaxial growth, thereby minimizing the influence of micro scratches, pits or stringers occurring on the bottom of the active region.