A semiconductor structure and a method for forming the semiconductor structure are provided. The semiconductor structure includes a substrate, and a first dielectric layer, a first gate structure and a plurality of second gate structures over the substrate. A second protection layer is formed on a top of a second gate structure. A first source-drain doped layer is formed between the first gate structure and an adjacent second gate structure. The first dielectric layer covers sidewalls of the first and second gate structures, and exposes a top surface of the second protection layer. The semiconductor structure also includes a first conductive structure in the first dielectric layer over the first source-drain doped layer, and a conductive layer on the first gate structure and the first conductive structure. A top surface of the conductive layer is coplanar with a top surface of the first dielectric layer.