At least one layer of insulator film (61-63) and single-crystal film (71-73) are alternately stacked and deposited on a surface of a semiconductor substrate (50), and an impurity-doped region (104-113) formed in each semiconductor film (71-73) is used as a gate, source or drain of a MOS transistor.
Thus, a three-dimensional semiconductor device is constructed in which MOS transistors are arranged, not only in the direction of the semiconductor substrate surface, but also in a direction perpendicular thereto.