シリコンウェーハ・エッジの高平坦仕上げを実現する研磨パッドの開発（静的・動的モデルによるエッジ平坦性の向上）

摘要

Recently the achievement of further high flatness of workpiece is strongly required in mirror finishing. Especially the edge roll off of silicon wafers as the substrates of semiconductor devices is demanded to decrease in polishing process for raising the yield of IC chips. However, the conventional polishing pad cannot meet the demand. In the previous study, a double-layered polishing pad having extra-fine fiber layer as upper layer and hard polymer layer as lower layer was developed to overcome the problem and it was found that the pad brought the high-flat edge and high finishing efficiency. In this study, constitution of the polishing pad was analyzed and investigated by using finite element method of a polishing model and considering the relative dynamic motion between the pad and the workpiece for improving the edge flatness further. A series of polishing experiments for silicon wafers revealed that the flatness of the edge shape is improved significantly with the newly developed pad based on the analytical results.%半導体デバイスのおもな基板材料であるシリコンウエーハは大口径化とともにさらなる高平坦化が進んでいる．しかし，研磨加工では工作物エッジがだれてしまう，いわゆるエッジ・ロールオフの問題がある．そのためシリコンウェーハにはチップ製造に利用できない外周額域として，エッジ部除外幅（Edge Exchusion ；E．E.）が設定されている．