Flash EEPROM cell and method of manufacturing the same

摘要

The invention relates to a flash EEPROM cell and method of manufacturing the same. The method of manufacturing a flash EEPROM cell includes sequentially forming a tunnel oxide film, a polysilicon layer for a floating gate and a hard mask layer on a semiconductor substrate; patterning the hard mask layer and then forming a hard mask layer spacer at the etching side of the patterned hard mask layer; removing the exposed portion of the polysilicon layer for the floating gate by etching process using the patterned hard mask layer and the hard mask layer spacer as etching masks thus to form first and second patterns that are separated in two; removing the patterned hard mask layer and the hard mask layer spacer and then depositing a dielectric film and a polysilicon layer for a control gate on the entire structure, thus forming a first floating gate, a second floating gate and a control gate by self-aligned etching process; and forming a drain junction and a source junction by cell source/drain ion implantation process. Thus, the present invention can prevent lower of the quality of the tunnel oxide film and thus increase the coupling ratio.