| 摘要 |
PURPOSE: A method for forming a gate electrode of a high integrated memory device having a dual gate and a silicide layer is provided to prevent dopant depletion in a gate polysilicon. CONSTITUTION: After a silicon substrate(1) is provided with an isolation layer(2) and a gate oxide(3), an undoped polysilicon layer(4) for a gate electrode is deposited on the gate oxide(3). Next, phosphorus ions are implanted into the polysilicon layer(4) at the first energy, and then arsenic ions are implanted into the polysilicon layer(4) at the second energy smaller than the first energy to prevent a decrease in a concentration of phosphorus ions in the polysilicon layer(4). Thereafter, a silicide layer is deposited on the polysilicon layer(4) and treated by heat. Finally, the silicide layer, the polysilicon layer(4) and the gate oxide(3) are patterned together, resulting in a gate electrode.
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