Abstract: A method for forming an isolation structure in a nonvolatile memory device includes forming a gate insulation layer, a gate conductive layer, and a hard mask over a substrate, etching the hard mask, the gate conductive layer, the gate insulation layer, and a portion of the substrate to form a trench, forming a first insulation layer over an inner surface of the trench and filled in a portion of the trench, removing the hard mask, and forming a second insulation layer over the first insulation layer and filled in the trench.

Abstract: A flash memory device and a method for fabricating the same are provided. The method includes: preparing a semi-finished substrate where floating gates and an isolation layer isolating the floating gates are formed; recessing a predetermined portion of the isolation layer to make the floating gates protrude; etching another predetermined portion of the isolation layer to form a trench therein; forming a dielectric layer over the isolation layer and the floating gates; and forming a control gate over the dielectric layer such that the control gate fills the trench.

Abstract: A method of manufacturing a flash memory cell is disclosed. The method comprises the steps of forming an oxide film on a semiconductor substrate in which a device separation film is formed and then patterning the oxide film to expose the semiconductor substrate at a portion in which a floating gate will be formed; sequentially forming a tunnel oxide film and a first polysilicon layer on the entire structure, and then flattening the first polysilicon layer until the tunnel oxide film is exposed to form a floating gate; etching the tunnel oxide film and the oxide film in the exposed portion to a given thickness and the forming a dielectric film on the entire structure; sequentially forming a second polysilicon layer, a tungsten silicide layer and a hard mask and then patterning them to form a control gate; and injecting impurity ions into the semiconductor substrate at the both sides of the floating gate to form a junction region.