Method for forming patterns for semiconductor device

Abstract

A method for forming patterns for semiconductor device includes following steps. A substrate including a hard mask layer and a sacrificial layer is provided. A plurality of mandrel patterns are formed on the substrate. A spacer is respectively formed on sidewalls of the mandrel patterns. The mandrel patterns are removed to form a plurality of spacer patterns directly formed on the sacrificial layer. A plurality of first blocking layers are formed in the sacrificial layer after forming the spacer patterns. A plurality of second blocking layers exposing at least a portion of the sacrificial layer and at least a portion of the first blocking layers are formed on the substrate. The sacrificial layer and the hard mask layer are etched with the spacer patterns, the first blocking layers, and the second blocking layers serving as etching masks to form a patterned hard mask layer on the substrate.