| 摘要 |
PROBLEM TO BE SOLVED: To raise the polishing efficiency of a silicon wafer, using polishing liquid which does not contain free abrasive grains, and to prevent the metallic pollution of the wafer at polishing. SOLUTION: The polishing liquid is made by adding an inorganic alkaline agent to pure water and adjusting the pH value of this solution to 11.0-12.5. Each quantity of KOH (or NaOH) and K2 CO3 (or Na2 Co3 ) to be added is 0.05-0.2 wt.%. A polishing tool (polishing roller, a polishing tape, etc.), where polishing abrasive grains are fixed to the polish working face, and a silicon wafer are set in a polisher. The polish working face of the polishing tool is brought into pressure contact with the surface of the silicon wafer so as to polish it, while supplying the surface of the silicon wafer with the above polishing liquid at a prescribed flow rate. As a result, a mirror face silicon wafer free of metallic pollution can be obtained at 0.5-0.7μm/min. As compared with the conventional polishing liquid consisting of pure water, this polishing liquid accelerates polishing of the semiconductor wafer by the molded item of the fixed abrasive grains. The polishing liquid is superior in stability, and forms a complex with metallic elements, so it can prevent pollution caused by the metallic element at the surface of the wafer.
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