FIGS. 6A and 6B show a cell structure for realizing the circuit structure shown in FIGS. 5A and 5B. FIG. 6A is a plan view, and FIG. 6B is a sectional view taken along a line 6B--6B in FIG. 6A. This is a stack cell structure in which the ferroelectric capacitors are formed after formation of the cell transistors, and more particularly, a bit line post-forming cell structure in which the bit lines