A semiconductor device and a method of fabricating same are disclosed. The semiconductor device includes: an SOI substrate including, stacked from the bottom upward, a lower substrate, a buried insulator layer and a semiconductor layer, wherein active regions surrounded by trench isolation structures are formed in the semiconductor layer; a gate electrode layer formed over the semiconductor layer, the gate electrode layer extending from active regions to trench isolation structures; and a source region and a drain region formed in the active regions that are on opposing sides of the gate electrode layer, wherein at least one end portion of the gate electrode layer laterally spans over interfaces of the active regions and the trench isolation structures toward the source region and/or the drain region. Thereby leakage at the interfaces of the active regions and the trench isolation structures can be reduced, resulting in improved performance of the semiconductor device.