A display device includes: a substrate; an inorganic insulating layer disposed on the substrate; a conductor disposed on the inorganic insulating layer; and an organic insulating layer disposed on the conductor, where an opening is defined through the organic insulating layer to expose a part of the upper surface of the conductor, and at least one material selected from a siloxane, a thiol, a phosphate, a disulfide including a sulfur series, and an amine is bonded on the part of the upper surface of the conductor exposed through the opening.