METHOD OF FORMING FINE PATTERNS IN SEMICONDUCTOR DEVICE

摘要

A method of forming fine patterns in a semiconductor device is provided to stably obtain fine patterns less than 50 nm with uniform vertical profile without generating undercut, by forming spaces on a sidewall of mask patterns. A method of forming fine patterns in a semiconductor device comprises the steps of: forming a plurality of first mask patterns(108) arranged such that the patterns are spaced in first intervals within a first region(A), and spaced in second intervals that is narrower than the first intervals within a second region(B), on a substrate(100) including a target etching layer(104a); successively forming a first layer(110) having a regular thickness, and a second layer made of a material having an etch selectivity with respect to the first layer, on a surface of the first mask patterns; partially removing the second layer to completely remove the second layer within the first region, and form a plurality of second mask patterns(114) made of residues of the second layer between the first mask patterns within the second region; forming a first spacer(118a) on sidewalls of an opening defined by removal of the second layer within the first region; partially removing the first layer to partially expose the first and second mask patterns, and form a plurality of second spacers made of the second layer on the sidewalls of the opening; and etching the target etching layer using the first and second mask patterns to form fine patterns.