エッジ・ロールオフ抑制に有効な研磨パッドの選定方法

抄録

As the substrates of semiconductor devices, silicon wafers are required to have extremely high surface flatness for increasing the integration density of the devices. Edge roll-off, which deteriorates the surface flatness near the wafer edge in polishing process as the final stage of the wafer manufacturing, is strongly demanded to be suppressed. Hardness is thought to be one of the most important specifications of polishing pads for estimating the obtained edge roll-off, and then compressibility of polishing pads is widely evaluated in practical process. However, it has not been clarified whether the obtained edge surface flatness can be estimated by the conventional hardness tests of polishing pads. In this study, we investigated the evaluation method of deformation property of polishing pads for estimating the obtained edge roll-off. Polishing experiments on silicon wafers confirmed that the obtained edge surface flatness was able to be estimated by the proposed evaluation method of deformation property of polishing pads.