The present disclosure provides a semiconductor structure having an insulating layer positioning on a substrate; a semiconductor fin partially located in the insulating layer; and a metal gate over the semiconductor fin and the insulating layer. The semiconductor fin includes a first region including a first lattice constant and a second region in proximity to the metal gate, including a second lattice constant. At least one dislocation is located only in the second region of the semiconductor fin. The present disclosure provides a method for manufacturing a semiconductor structure, including forming a gate over a first semiconductor layer, removing a portion of the first semiconductor layer in proximity to a sidewall of the gate and obtaining a recess, and forming a second semiconductor layer in the recess. At least one dislocation is in-situ formed in the second semiconductor layer without extending to the first semiconductor layer.