Patent ID: 9070640
Filing Date: 2015-06-30
Classification: H01L

Abstract:
1. A method of forming fine patterns, the method comprising: providing a structure including a lower mask layer, a hard mask layer stacked on the lower mask layer and a buffer mask layer stacked on the hard mask layer; patterning the hard mask layer and the buffer mask layer to form first openings therein; forming sacrificial patterns filling the first openings, the sacrificial patterns protruding from a top surface of the buffer mask layer; forming a spacer pattern filling spaces between sacrificial patterns adjacent to each other, the spacer pattern having gaps therein, and each of the gaps exposing a respective portion of the buffer mask layer located in a central region of a polygon whose vertices coincide with the locations of sacrificial patterns adjacent to each other, respectively; etching portions of the buffer mask layer exposed by the gaps of the spacer pattern to form holes therein that expose the hard mask layer; etching portions of the hard mask layer exposed by the holes in the buffer mask layer to form second openings in the hard mask layer; and subsequently etching the lower mask layer using the hard mask as an etch mask.