A semiconductor device including a substrate having a central region and a peripheral region; an integrated circuit structure on the central region; and a first structure on the peripheral region and surrounding the central region, wherein a portion of the first structure includes a first fin structure defined by a device isolation region in the substrate; a first dielectric layer covering an upper surface and side surfaces of the first fin structure and an upper surface of the device isolation region; a first gate structure on the first fin structure, the first gate structure including a first gate conductive layer, a first gate dielectric layer covering lower and side surfaces of the first gate conductive layer, and first gate spacer layers on side walls of the first gate conductive layer; and a first insulating structure covering the first dielectric layer and the first gate structure.