Formation method of semiconductor structure

A formation method of a semiconductor structure comprises the following steps: etching the side wall of an initial first mask layer, reducing the size of the initial first mask layer along the extension direction of an initial fin structure, and forming a first mask layer; forming an initial isolation layer covering the first mask layer, wherein the initial isolation layer exposes the top surface of the first mask layer; after the initial isolation layer is formed, removing the first mask layer; and after the first mask layer is removed, etching the initial fin structure by taking the initial isolation layer as a mask. By controlling the process parameters of etching the initial first mask layer, the width of the formed first mask layer can be small enough, the accuracy is high, the process difficulty is effectively reduced, the size of the formed opening is small enough, and the performance of the formed semiconductor structure can be improved. 一种半导体结构的形成方法，包括：刻蚀所述初始第一掩膜层侧壁，减小所述初始第一掩膜层沿初始鳍部结构延伸方向上的尺寸，形成第一掩膜层