Method of forming fine pitch hardmask patterns and method of forming fine patterns of semiconductor device using the same

A method of forming hardmask patterns, comprising:

• forming a hardmask layer on a substrate;
• forming a plurality of first mask patterns on the hardmask layer at a first pitch;
• forming a buffer layer covering the plurality of first mask patterns, and having an upper surface having recesses between adjacent first mask patterns;
• forming second mask patterns filling in the recesses formed in the upper surface of the buffer layer,
• partially removing the buffer layer to simultaneously expose upper surfaces of the plurality of first mask patterns and the upper surfaces of the second mask patterns;
• partially removing the buffer layer using the plurality of first mask patterns and the second mask patterns as an etch mask to expose the upper surface of the hardmask layer between the first mask pattern and the second mask pattern;
• and
• etching the hardmask layer using the first mask patterns and the second mask patterns as an etch mask to form a plurality of hardmask patterns at a second pitch which is about ½ of the first pitch.

A method of forming fine patterns of a semiconductor device, comprising:

• forming a first oxide film on a substrate;
• forming a hardmask layer by stacking a nitride film and a second oxide film on the first oxide film;
• forming a plurality of first mask patterns on the second oxide film;
• forming a third oxide film on the first mask patterns, the third oxide film having an upper surface that defines recesses between adjacent first mask patterns;
• forming second mask patterns within the recesses formed in the upper surface of the third oxide film;
• partially removing the third oxide film to expose the upper surfaces of the first mask patterns;
• partially removing the third oxide film to expose the hardmask layer using the first mask patterns and the second mask patterns as an etch mask;
• etching the hardmask layer using the first mask patterns and the second mask patterns as an etch mask to form hardmask patterns;
• etching the first oxide film and the substrate using the hardmask patterns as an etch mask to form trenches in the substrate, and
• filling the trenches with an insulating film to form an isolation region.

A method of forming fine patterns of a semiconductor device, comprising:

• forming a hardmask layer on an etch film subjected to etching on a substrate;
• forming a plurality of first mask patterns on the hardmask layer;
• forming a buffer layer on the first mask patterns, the buffer layer having an upper surface defining recesses between adjacent first mask patterns;
• forming second mask patterns within the recesses formed in the upper surface of the buffer layer;
• partially removing the buffer layer to expose upper surfaces of the first mask patterns;
• partially removing the buffer layer using the first mask patterns and the second mask patterns as an etch mask to expose the hardmask layer;
• etching the hard mask layer using the first mask patterns and the second mask patterns as an etch mask to form hardmask patterns;
• and
• etching the etch film using the hardmask patterns as an etch mask.