Patent ID: 10529570

Abstract:
A method for preparing a semiconductor structure includes the following steps. A target layer is formed over a substrate. A first patterned mask is formed over the target layer and includes plural first openings separate from each other. The first openings are filled with a first sacrificial layer. A patterned core layer is formed on the first sacrificial layer and includes plural closed patterns and plural second openings within the closed patterns of the patterned core layer. Plural spacers are formed on sidewalls of the patterned core layer. The spacers are removed to form a plurality of third openings over the substrate. The first sacrificial layer and the first patterned mask are etched through the third openings. The first sacrificial layer is removed to form a second patterned mask on the target layer. The target layer is etched through the second patterned mask to form a patterned target layer.