Semiconductor device and manufacturing method therefor

The invention discloses a semiconductor device and a manufacturing method therefor. The method comprises the steps: providing a substrate structure which comprises a substrate, one or more semiconductor fins on the substrate, and a trench isolation structure around each fin. Each trench isolation structure comprises a first trench isolation part and a second trench isolation part, which are located at two sides of the corresponding fin in the longitudinal direction; and also comprises a third trench isolation part and a fourth trench isolation part, which are located at two ends of the corresponding fin in the longitudinal direction. The method also comprises the steps: forming a patterned first hard mask layer on the substrate structure, wherein the patterned first hard mask layer is provided with an opening, so as to expose the upper surfaces of the corresponding third and fourth trench isolation parts; forming a first insulating material layer, so as to achieve the filling of the opening and to form an ins