Method for separating fine patterns of a semiconductor device

Abstract

A method for forming a fine pattern of a semiconductor device, in which a first-to-be-patterned layer is formed on a semiconductor substrate, a photoresist film is coated on the first-to-be-patterned layer, and the photoresist film is patterned and cured to obtain a thermally stable photoresist film pattern. Thereafter, a second material layer is formed on the entire surface of the semiconductor substrate on which the photoresist film pattern is formed, by a low temperature plasma method, and the second material layer is anisotropically etched to thereby form a spacer made of the second material layer on the sidewalls of the photoresist film pattern. A first pattern is formed by anisotropically etching the first-to-be-patterned layer, using the spacer and the photoresist film pattern as an etching mask. The spacer and the photoresist film pattern are then removed. Using the first pattern thus obtained, a fine pattern which is the inverse of the first pattern can be formed. The separation interval between the individual elements can be reduced so as to be less than or equal to the minimum design rule, and a fine pattern below optical resolution can be attained.

Dependencies are inferred from the claim text.