Semiconductor structure and forming method thereof

Abstract

A semiconductor structure and a forming method thereof are provided. The forming method includes: providing a base, where the base includes a first region; forming a bottom core material layer on the base; forming separate first core layers on the bottom core material layer of the first region; forming a first spacer on a side wall of the first core layer; removing the first core layer; after removing the first core layer, forming a second spacer on a side wall of the first spacer, where the first spacer and the second spacer located on the side wall of the first spacer constitute a main spacer structure layer; patterning the bottom core material layer by using the main spacer structure layer as a masking film to form a second core layer; removing the main spacer structure layer; after removing the main spacer structure layer, forming a third spacer on a side wall of the second core layer; removing the second core layer; and after removing the second core layer, patterning the base by using the third spacer as a masking film to form a desired pattern. Embodiments of the present disclosure can meet the demand of different types of pitches between the desired patterns, and are beneficial to accurately controlling the pitches between the desired patterns.