A method of manufacturing a nonvolatile memory device wherein first gate lines and second gate lines are formed over a semiconductor substrate. The first gate lines are spaced-from each other at a first width, the second gate lines are spaced-from each other at a second width, and the first width is wider than the second width. A first ion implantation process of forming first junction regions in the semiconductor substrate between the first gate lines and the second gate lines is performed. A second ion implantation process of forming second junction regions in the respective first junction regions between the first gate lines is then performed.