The invention relates to a method for forming a semiconductor structure, comprising: providing a semiconductor substrate which comprises a dummy gate formed thereon, a spacer surrounding the dummy gate, source and drain regions formed on two sides of the dummy gate, respectively, and a channel region formed in the semiconductor substrate and below the dummy gate; removing the dummy gate to form a gate opening; forming a stressed material layer in the gate opening; performing an annealing to the semiconductor substrate, the stressed material layer having tensile stress characteristics during the annealing; removing the stressed material layer in the gate opening; and forming a gate in the gate opening. By the above steps, the stress memorization technique can be applied to the pMOSFET.