METHOD OF FABRICATING FLASH MEMORY DEVICE TO INCREASE COUPLING RATIO BETWEEN FLOATING GATE AND CONTROL GATE

摘要

PURPOSE: A method of fabricating a flash memory device is provided to increase a coupling ratio between a floating gate and a control gate by forming an uneven part on an upper surface of the floating gate by an etch process using a photoresist pattern having an uneven surface. CONSTITUTION: A tunnel oxide layer(22) and a floating gate polysilicon layer(23) are formed on a semiconductor substrate(21) including an isolation layer. A photoresist pattern is formed on the floating gate polysilicon layer. The floating gate polysilicon layer is patterned by an etching process. An uneven structure is formed on the patterned floating gate polysilicon layer. Residues of the photoresist patterns are removed therefrom. A dielectric layer(28) and a conductive material layer(29) for control gate are formed on the floating gate polysilicon layer. A control gate is formed by a second etching process.