Method of manufacturing a semiconductor device

A method for fabricating a semiconductor device, the method comprising:

• forming a spacer structure in which first and second spacers extending in a first direction are spaced apart from each other and alternately disposed along a second direction on an etch target layer, wherein the first spacers and the second spacers are formed of materials having different etch rates;
• forming first spacer lines having end portions that are aligned with a third direction, the third direction intersecting with the first direction, through selective etching of the first spacers;
• forming second spacer lines having end portions that are aligned with a fourth direction, the fourth direction being parallel with the third direction, through selective etching of the second spacers;
• and
• etching the etch target layer using the first and second spacer lines to form first line patterns having end portions aligned with the third direction and second line patterns having end portions aligned with the fourth direction.