A semiconductor device includes conductive lines spaced from a substrate, and an insulating spacer structure between the conductive lines and defining a contact hole. The insulating spacer structure is adjacent a side wall of at least one of the conductive lines. The device also includes an insulating pattern on the conductive lines and insulating spacer structure, and another insulating pattern defining a landing pad hole connected to the contact hole. A contact plug is formed in the contact hole and connects to the active area. A landing pad is formed in the landing pad hole and connects to the contact plug. The landing pad vertically overlaps one of the pair of conductive line structures.