A method for forming a dual interlayer dielectric layer, which is capable of preventing an interlayer delamination phenomenon generated between an etch stop layer and an interlayer dielectric layer is provided. An interlayer dielectric layer of a dual structure is formed such that a first interlayer dielectric layer and a second interlayer dielectric layer are sequentially stacked on the etch stop layer. The etch stop layer is formed on a substrate, the substrate having a source/drain region and a gate formed therein. The dual interlayer dielectric layer is selectively etched, and a conductive material is deposited thereon, thereby forming a contact. The O3-TEOS layer and the PE-TEOS layer used as the first interlayer dielectric layer can relieve a compressive stress and improve adhesion force, respectively, thereby preventing the interlayer delamination phenomenon.