Semiconductor structure and manufacturing method thereof

A method for manufacturing a semiconductor structure, comprising:

• providing a substrate, a groove structure being forming in the substrate;
• forming a laminated structure on the substrate, the laminated structure comprising a first conductive material layer, a second conductive material layer and an insulating material layer from bottom up, wherein the first conductive material layer fills the groove structure and covers the surface of the substrate;
• and
• etching the insulating material layer, the second conductive material layer and the first conductive material layer sequentially to form an insulating layer, a second conductive layer, and a first conductive layer, respectively, the insulating layer, the second conductive layer and the first conductive layer jointly forming a first pattern structure;
• wherein a process of etching the first conductive material layer comprises a first etching stage and a second etching stage, wherein in the first etching stage, a first etching gas is used for etching the first conductive material layer until an upper surface of the substrate is exposed;
• and in the second etching stage, a second etching gas is used for etching the first conductive material layer, and
• wherein, a bottom width of the first pattern structure located in the groove structure is not smaller than that of the first pattern structure located outside the groove structure.