The present disclosure provides a method for forming an integrated circuit (IC) structure. The method comprises providing a substrate including a conductive feature; forming aluminum (Al)-containing dielectric layer on the conductive feature; forming a low-k dielectric layer on the Al-containing dielectric layer; and etching the low-k dielectric layer to form a contact trench aligned with the conductive feature. A bottom of the contact trench is on a surface of the Al-containing dielectric layer.