A semiconductor structure and a method for forming the same are provided. The method includes: providing a base, a pattern transfer material layer being formed above the base; performing first ion implantation, to dope first ions into the pattern transfer material layer, to form first doped mask layers arranged in a first direction; forming first trenches in the pattern transfer material layer on two sides of the first doped mask layer in a second direction, to expose side walls of the first doped mask layer; forming mask spacers on side walls of the first trenches; performing second ion implantation, to dope second ions into some regions of the pattern transfer material layer that are exposed from the first doped mask layers and the first trenches, to form second doped mask layers; removing the remaining pattern transfer material layer, to form second trenches; and etching the base along the first trenches and the second trenches, to form a target pattern. The present disclosure improves the accuracy of pattern transfer.