Patent ID: 7358138

Claim:
A method of manufacturing a flash memory device, the method comprising the steps of: sequentially forming a tunnel oxide film, an oxide film, and a first conductive layer on a semiconductor substrate; infiltrating a first etchant between grains of the first conductive layer to form a plurality of nano-crystal points in the oxide film; removing the first conductive layer using a second etchant, wherein during the process of removing the first conductive layer, portions of the nano-crystal points of the oxide film are removed by the second etchant, thereby forming a plurality of nano-crystals formation holes in the oxide film; filling the plurality of holes with a non-conductive layer to form a plurality of nano-crystals respectively having an isolated shape; sequentially forming a dielectric layer and a second conductive layer on the oxide film including the plurality of nano-crystals; and sequentially patterning the second conductive layer, the dielectric layer, the oxide film including the nano-crystals, and the tunnel oxide film.