Semiconductor memory device having improved memory cells provided with cylindrical type capacitors

摘要

A semiconductor memory device having a storage region constituted with the arrangement of a plurality of memory cells on a main surface of a semiconductor substrate. Each memory cell includes a switching element and a passive element for signal retention connected to the switching element, for retaining the electric charges transferred from the switching element. The passive element includes a central electrode having a generally columnar shape provided protruded on the main surface in a first direction away from the main surface, and the fins constituted with a conductor extending in the first direction and protruded from the outer periphery of the central electrode. Owing to the existence of the fins, the surface area of a signal storage electrode of the passive element is increased. In other words, the quantity of electric charges to be stored is increased.