Method of making a semiconductor memory device

Claim 1

In a method of manufacturing a node electrode of a dynamic random access memory consisting essentially of one MOS transistor and one stacked capacitor, the method of manufacturing a semiconductor memory device comprising the processes of: forming a MOS transistor consisting essentially of a gate electrode serving both as a gate electrode with a gate insulating film and as a word line, an n-type node diffused layer and an n-type bit diffused layer that are formed on the surface of a p-type silicon substrate, depositing an interlayer insulating film over all of a surface of the MOS transistor, and opening a node contact hole in said interlayer insulating film that reaches said node diffused layer; forming a stacked film by alternately depositing a first conductor film and a second conductor film wherein, said first conductor film consists essentially of an n-type polycrystalline silicon film, and said second conductor film consists essentially of an oxygen-rich n-type polycrystalline silicon film, and the formation process of said stacked film comprises the processes of: carrying out alternately deposition of an undoped polycrystalline silicon film, and formation of an oxygen-rich undoped polycrystalline silicon film on the surface of said undoped polycrystalline silicon film by exposing said undoped polycrystalline silicon film to an oxygen atmosphere, and forming a first stacked film consisting essentially of said undoped polycrystalline silicon film and said oxygen-rich undoped polycrystalline silicon film; and diffusing phosphorus into said first stacked film; forming a photoresist film in a region for forming a node electrode, and anisotropically etching said stacked film using said photoresist film as a mask; and isotropically etching at least a surface of said stacked film exposed by said anisotropic etching.