| 摘要 |
PURPOSE: A method for fabricating a flash memory device is provided to prevent a decrease of a source line width and thereby to prevent a decrease of resistance. CONSTITUTION: In a fabrication of a flash memory device, a semiconductor substrate(201) on which a floating gate and a control gate form a stack gate is provided. The stack gate is composed of a tunnel oxide(202), a first polysilicon layer(203), a dielectric layer(204), a second polysilicon layer(205), a tungsten silicide layer(206) and a nitride layer(207). Next, a photoresist layer(208) is deposited and patterned by using a self-aligned source mask to define a common source line. A trench(209) is then formed in the substrate(201) by an anisotropic etching method to increase effective width of the source line. Also, a tilt implantation process is performed by using the patterned photoresist layer(208) as an implant mask. After the photoresist layer(208) is removed, another ion implantation process is again performed using another photoresist layer. Thereby, the common source(210) and drains(211) are formed in the substrate(201).
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