The present invention provides a method for manufacturing a semiconductor structure, which comprises: a) providing a substrate (100); b) forming a dummy gate stack on the substrate (100), wherein the dummy gate stack consists of a gate dielectric layer (203) and a dummy gate (201) located on the gate dielectric layer (203), and the material of the dummy gate (201) is amorphous Si; c) performing ion implantation to regions exposed on both sides of the dummy gate (201) on the substrate (100), so as to form source/drain regions (110); d) forming an interlayer dielectric layer (400) that covers the source/drain regions (110) and the dummy gate stack; e) removing part of the interlayer dielectric layer (400) to expose the dummy gate (201) and removing the dummy gate (201); and f) annealing to activate dopants in source/drain regions. Procedures of the traditional gate-replacement process have been modified by the method for manufacturing a semiconductor structure provided by the present invention, thus etching period can be easily controlled, etching difficulty is alleviated, and stability of etching process is guaranteed as well.