Semiconductor structure and forming method thereof

Abstract

A semiconductor structure and a forming method thereof are provided. In one form, a forming method includes: forming separated mandrel lines, where opposite sidewalls of adjacent mandrel lines in a second direction are a first sidewall and a second sidewall; forming a sacrificial spacer on a sidewall of the mandrel line; forming a sacrificial layer on a part of the base between adjacent sacrificial spacers; forming a filling layer on the base; removing the sacrificial layer to form an opening; removing the sacrificial spacer to form a trench; forming a mask spacer on a sidewall of the trench, where the mask spacer is further filled between the sidewall of the mandrel line and the filling layer, and the mask spacer located on the sidewall of the trench forms a first groove; forming a second groove running through the filling layer between the sidewall of the trench and the mask spacer located on the second sidewall; removing the mandrel line to form a third groove, where a cutting layer is formed in at least one of the third groove, the second groove, and the first groove, and the cutting layer cuts the corresponding groove along the first direction; and patterning a target layer below the third groove, the second groove, and the first groove to form a target pattern. The embodiments in the present disclosure improve the pattern precision of the target pattern.