Semiconductor structures is provided. The semiconductor structure includes a semiconductor substrate having a first region and a second region. A surface of the first region of the semiconductor substrate contains a gate structure, a surface of the second region of the semiconductor substrate contains a dummy gate structure, and the semiconductor substrate under the dummy gate structure contains an isolation structure. The semiconductor structure further includes a bulk layer having a substantially flat reshaped surface formed in the semiconductor substrate at each of two sides of the gate structure; and a protective layer formed on the reshaped surface of the bulk layer.