In the double-sided polishing process of silicon wafers, there is a strong demand to reduce amount of edge roll-off (ERO) while improving global flatness of a wafer. In the present study, we clarified the negative effects of uneven wear of the polishing pads on the global flatness of a wafer can be suppressed when the deformation of the polishing pads is large. As for the ERO, we found small deformation of the polishing pad near the top surface was effective in reducing the amount of ERO. In addition, we revealed small distance from the surface of the polishing pad at the area under the wafer to that at the area around the wafer was also effective in reducing the amount of ERO. On the basis of the findings, we developed a three-layered polishing pad which was expected to reduce the amount of ERO while achieving the good global flatness.

在硅晶片的双面抛光工艺中，强烈要求减少边缘滚落（ERO）的数量，同时改善晶片的整体平坦度。在本研究中，我们阐明了当抛光垫的变形较大时，可以抑制抛光垫的不均匀磨损对晶片整体平面度的负面影响。至于ERO，我们发现靠近顶部表面的抛光垫小变形可有效减少ERO的数量。另外，我们发现从抛光垫的表面到晶片下方的区域与晶片周围的区域的距离很小，这对于减少ERO量也是有效的。基于这些发现，我们开发了一种三层抛光垫，有望减少ERO的数量，同时获得良好的整体平坦度。