| 摘要 |
PURPOSE: A polysilicon plug formation method of semiconductor devices is provided to prevent a local loss by using a polysilicon slurry having a high polishing selectivity compared to the polysilicon. CONSTITUTION: A diffusion barrier metal(3), a bit line metal(4), a buffer layer(5), a mask oxide(6) and a polysilicon hard mask are sequentially formed on a word line insulator(1) and a metal plug(2). A bit line pattern is formed by patterning the polysilicon hard mask, the mask oxide, the buffer layer, the bit line metal and the diffusion barrier metal. An oxide spacer is formed at both sidewalls of the bit line pattern. After forming a polysilicon plug on the resultant structure, a bit line insulator is deposited. The resultant structure is polished to expose the mask oxide(6) by using a slurry for polishing an oxide. The polysilicon plug is isolated by polishing the mask oxide(6) using a polysilicon slurry.
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