| 摘要 |
PURPOSE: A method for CMP(chemical mechanical polishing) of ruthenium titanium oxide layer is provided to improve the polishing speed of the RTO and to reduce defects by adding nitric acid and ceric ammonium nitrate to an abrasive. CONSTITUTION: An RTO layer(200a) as a barrier metal is deposited on a semiconductor substrate(100) having a storage node contact hole buried in a gate(120), an oxide layer(140) ad a polysilicon layer(160). At this time, the RTO layer(200a) is selectively removed by CMP using slurry. The slurry is provided with an abrasive made of CeO2 or ZrO2 and an additive composed of nitric acid and ceric ammonium nitrate.
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