Fin structure for vertical field effect transistor having two-dimensional shape in plan view

A method for manufacturing a fin structure for a vertical field effect transistor (VFET), the method comprising:

• forming a plurality of mandrels on a substrate, the mandrels having at least one first gap therebetween;
• forming a plurality of first spacers on side surfaces of the mandrels, respectively, such that at least one second gap, which is smaller than the first gap, is formed between the first spacers;
• forming a second spacer on side surfaces of the first spacers;
• removing the mandrels and the first spacers to leave the second spacer formed on the side surfaces of the first spacers;
• removing the second spacer, formed on the side surfaces of the first spacers, at a predetermined portion so that the remaining second spacer has a same two-dimensional (2D) shape as the fin structure;
• and
• removing a portion of the substrate, except below the remaining second spacer, and the remaining second spacer so that the substrate below the remaining second spacer forms the fin structure.