Polishing pad and cushion layer for polishing pad
A polishing pad includes at least a polishing layer and a cushion layer and is characterized in that the difference in hardness in Shore D hardness between the polishing layer and the cushion layer is 3 or more.
1. A polishing pad comprising:
a polishing layer having a polishing side surface configured to polish a semiconductor wafer with a circuit pattern; and
a cushion layer integrally formed on top of the polishing layer opposite to the polishing side surface, wherein the cushion layer has a compression recovery of 90% or more, contains a photosetting material having rubber elasticity, and has a platen attachment side surface opposite to the polishing layer and configured to be attached to a platen; said platen attachment side surface having a plurality of recesses etched in a thickness direction, each recess of the platen attachment side surface being defined by side walls substantially perpendicular to a plane of the platen attachment side surface wherein said side walls are attached to a concave upper portion and a lower convex portion.
2. A polishing pad according to claim 1 , wherein the material having rubber elasticity comprises a rubber-type resin having compressibility and a photosetting resin.
3. The polishing pad according to claim 1 , wherein the plurality of recesses of the platen attachment side surface are constructed by a plurality of grooves.
4. The polishing pad according to claim 1 , wherein the plurality of recesses of the platen attachment side surface are constructed by a half-tone dot structure containing a plurality of holes.