Patent ID: 9224874
Filing Date: 2015-12-29
Classification: H01L

Abstract:
1. A semiconductor storage device comprising: a semiconductor pillar; a tunnel insulating film directly on a side surface of the semiconductor pillar; a charge accumulation layer directly on a side surface of the tunnel insulating film; an intermediate dielectric film directly on a side surface of the charge accumulation layer; and a control gate electrode around the intermediate dielectric film, wherein the intermediate dielectric film includes a laminated film of silicon oxide films of multiple layers, silicon nitride films of at least one layer, and a silicon oxynitride film, and wherein an oxygen content of the silicon oxynitride film is CNTo and a nitrogen content of the silicon oxynitride film is CNTn, and the nitrogen content CNTn/(CNTo+CNTn) of the silicon oxynitride film decreases gradually or in a stepwise manner from the silicon nitride film adjacent to one side of the silicon oxynitride film to the silicon oxide film adjacent to the other side of the silicon oxynitride film.