Layer structure having contact hole, method of producing the same, fin- shaped capacitor using the layer structure, method of producing the fin- shaped capacitor and dynamic random access memory having the fin- shaped capacitor

摘要

A dynamic random access memory (DRAM) device includes a stacked capacitor including a storage electrode, a dielectric film and a cell plate. In a preferred embodiment, the storage electrode contacts with a diffusion region of a substrate through a contact hole. The storage electrode has a first fin which has a first uniform portion with a width greater than the width of the contact hole, and a second uniform portion serving as a side wall, which is formed around an inner-wall of the first uniform portion defining the first opening, so that a second opening defined by the second uniform portion, has a width which is substantially identical to the width of the contact hole. The use of the second uniform portion to form the stacked capacitor allows for a reduction in the size of the contact hole relative to the conventional DRAM devices, and therefore allows for a reduction in the overall size of the DRAM device of the present invention, relative to conventional DRAM devices.