Provided are a semiconductor device and a method of fabricating the semiconductor device. The semiconductor device includes a first conductive well region in a semiconductor substrate and a second conductive well region on or in the first conductive well region. A gate electrode is in a trench on a gate insulation layer, and the trench is in the second conductive region and the first conductive well region. A drain includes a drain insulation layer, a (polysilicon) shield layer, and drain plug. The drain insulation layer is in a trench in the second conductive region and the first conductive well region. The shield layer encloses the drain plug. A lower portion of the drain plug contacts the second conductive well region. A first conductive source region is at a side of the gate electrode.