In a method, a charged metal dot is deposited on a first position of a surface of a semiconductor substrate. Then, a charged region is formed on a second position of the surface of the semiconductor substrate, thereby establishing of which an electric field direction from the first position toward the second position. The first position is spaced apart from the second position by a distance. Thereafter, a precursor gas flows along the electric field direction on the semiconductor substrate, thereby forming a carbon nanotube (CNT) on the semiconductor substrate.