FIGS. 7A and 7B show another cell structure for realizing the circuit structure shown in FIGS. 5A and 5B. FIG. 7A is a plan view, and FIG. 7B is a sectional view taken along a line 7B--7B in FIG. 7A. 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 pre-forming cell structure in which the bit l