METHOD OF FORMING AN ETCHING MASK

摘要

A method for forming an etch mask is provided to obtain ultra-fine line/space patterns by forming a plurality of spacers using two materials with different etch selectivity. A pre-pattern(204) containing a first material is formed on a substrate(200). A first spacer(208) is formed at both sidewalls of the pre-pattern. The first spacer contains a second material with a relatively different etch selectivity compared to the first material. The width of the first spacer is the same as that of the pre-pattern. A second spacer(210) is formed at each sidewalls of the first spacer. The second spacer contains the first material. The width of the second spacer is the same as that of the pre-pattern. A third spacer(212) is formed at each sidewall of the second spacer. The third spacer contains a second material. The width of the third spacer is the same as that of the pre-pattern. A thin film(214) containing the first material is formed on the resultant structure.