Provided is a manufacturing method of s semiconductor structure. The method includes: providing a substrate, wherein the substrate has a plurality of fin portions and at least one recessed portion, the at least one recessed portion is located between two adjacent fin portions of the plurality of fin portions and a bottom surface of the at least one recessed portion is lower than a surface of the substrate between the two of the plurality of fin portions; forming a doping layer on a sidewall of the plurality of fin portions, the surface of the substrate, and a sidewall and a bottom portion of the at least one recessed portion; and forming a dielectric layer on the doping layer. A top surface of the doping layer and a top surface of the dielectric layer are lower than a top surface of each of the plurality of fin portions.