A moisture blocking structure includes an active fin disposed on a sealing region of a substrate, the substrate including a chip region and the sealing region surrounding a periphery of the chip region, the active fin continuously surrounding the chip region and having a winding line shape in a plan view. A gate structure covers the active fin and surrounds the periphery of the chip region. A conductive structure is disposed on the gate structure, the conductive structure surrounding the periphery of the chip region.