POLISHING SHEET

To provide a polishing sheet that is suited for mirror polishing, and capable of obtaining a mirror plane of higher quality, that is a mirror plane with high specular in-plane uniformity and less flaws, in silicon bare wafers, glass, compound semiconductor substrates and hard disk substrates or the like.SOLUTION: A polishing sheet in the present invention has, on its surface layer, a soft porous layer which includes: a plurality of apertures on its surface; and a plurality of teardrop-like holes from the apertures to an internal part. In the polishing sheet, there are a plurality of almost linear grooves within a range of the soft porous layer surface of the polishing sheet that is brought into contact with a polishing object substrate during polishing. At least some of the grooves exist independently without intersecting with the other grooves.SELECTED DRAWING: Figure 8 【課題】シリコンベアウエハ、ガラス、化合物半導体基板およびハードディスク基板等においてより品質の高い鏡面、すなわち鏡面性の面内均一性が高く、欠陥が少ない鏡面を得られる、鏡面研磨に好適な研磨シートを提供する。【解決手段】本発明の研磨シートは、表面に複数の開口部を有し、前記開口部から内部に涙滴状の孔を複数有する軟質多孔層を表層に有する研磨シートであって、被研磨基板が研磨中に接触する研磨シートの該軟質多孔層表面の範囲内には略直線状の溝が複数あり、少なくとも一部の溝は、他の溝とは交わらずに独立して存在していることを特徴とする。【選択図】図８