| 摘要 |
PURPOSE: A gate formation method in flash memory device is provided to be capable of improving reliability of devices, by solving the problem of polysilicon residue generated upon etch process for forming a gate pattern. CONSTITUTION: A gate oxide film(12), the first doped polysilicon film(13), a dielectric film(14), the second doped polysilicon film(15), the third undoped polysilicon film(16), a tungsten silicide film(17) and an anti-reflection film(18) are sequentially formed on a semiconductor substrate(11). The anti-reflection film, the tungsten silicide film, the third undoped polysilicon film and the second doped polysilicon film are then patterned by lithography and etching process, thus forming a control gate. Next, the dielectric film and the first polysilicon film are patterned by self-aligned etch process using the patterned anti-reflection film as a mask, thus forming a floating gate.
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