Method of manufacturing semiconductor devices

A method of manufacturing a semiconductor device, the method comprising:

• preparing a lower structure having a first region, a second region, and a third region;
• forming a first sacrificial core having a first width on the first region, a second sacrificial core having a second width on the second region, and a third sacrificial core having a third width, greater than the first width and the second width, on the third region;
• forming spacers on the first region of the lower structure, a first mask structure including the second sacrificial core and the spacers on the second region of the lower structure, and a second mask structure including the third sacrificial core and the spacers on the third region of the lower structure;
• and
• etching the lower structure using the spacers, the first mask structure, and the second mask structure,
• wherein the first width is equal to the second width, and a width of the spacers is equal to the first width.

A method of manufacturing a semiconductor device, the method comprising:

• stacking a lower sacrificial layer and an upper sacrificial layer on a lower structure having a first region, a second region, and a third region;
• forming a first upper sacrificial core on the first region and a second upper sacrificial core on the second region by etching the upper sacrificial layer;
• forming first spacers on side walls of the first upper sacrificial core and side walls of the second upper sacrificial core;
• removing the first upper sacrificial core and the second upper sacrificial core;
• forming a photoresist pattern having a width wider than a width of the first upper sacrificial core on the third region;
• forming first lower sacrificial cores on the first region, second lower sacrificial cores on the second region, and a third lower sacrificial core on the third region, by etching the lower sacrificial layer using the first spacers and the photoresist pattern as an etching mask;
• forming second spacers on side walls of first lower sacrificial cores, side walls of second lower sacrificial cores, and side walls of a third lower sacrificial core;
• forming a protective pattern covering the second region and the third region;
• removing the first lower sacrificial cores formed on the first region;
• and
• etching the lower structure using the second spacers on the first region, the second lower sacrificial cores and the second spacers on the second region, and the third lower sacrificial cores and the second spacers on the third region.