Method for forming patterns

A method for forming patterns comprising:

• forming etch target lines isolated from one another over a substrate;
• forming an etch barrier stack in which a first sacrificial material, first mask lines, a second sacrificial material and second mask lines intersecting with the first mask lines are sequentially disposed on the etch target lines;
• sequentially etching the second sacrificial material and the first sacrificial material using the second and first mask lines as etch masks to form island-shaped sacrificial openings isolated from one another in the first sacrificial material;
• forming island-shaped sacrificial pillars to fill the island-shaped sacrificial openings;
• etching the first mask lines to form island-shaped masks at intersections between the first mask lines and the second mask lines;
• etching the first sacrificial material using the island-shaped masks and the island-shaped sacrificial pillars as etch masks to form a sacrificial barrier including island-shaped openings that are isolated from one another to partially expose the etch target lines;
• and
• etching the etch target lines using the sacrificial barrier as an etch mask to form island-shaped patterns isolated from one another and isolation holes by cutting the etch target lines.