Method for forming a semiconductor structure

摘要

A method for semiconductor structure formation includes: providing a substrate; forming a first lower mask layer on the substrate; forming a first patterned mask on the first lower mask layer; forming a second lower mask layer on the first lower mask layer and overlaying the first patterned mask; forming a second patterned mask on the second lower mask layer without the second patterned mask overlapping the first patterned mask; etching and undercutting the first lower mask layer and the second lower mask layer to form the third patterned mask with the first patterned mask and the second patterned mask; etching the substrate by using the third patterned mask to form a plurality of islands; and removing the third patterned mask.