Polishing pad
The present invention provides a polishing pad which can improve qualities of an object to be polished by improving the flatness of the object. A polishing surface 1 a of a polishing pad 1 is subjected to a mechanical process, such as buffing, so that the flatness of the surface is improved, and corrugations on the polishing surface have a cycle of 5 mm-200 mm and a largest amplitude of 40 μm or less. As a result, the flatness of the object polished by the polishing pad 1 , such as a silicon wafer, is improved.
1. A polishing pad for polishing an object to be polished, the polishing pad comprising a polishing surface to be pressed onto the object to be polished, wherein:
the polishing surface has waviness having dimensions in a range of 5 mm-200 mm along the polishing surface, and
a largest amplitude of the waviness is 40 μm or less.
2. A polishing pad for polishing an object to be polished, the polishing pad comprising a polishing surface to be pressed onto the object to be polished, wherein a zeta potential of the polishing surface, before a break-in process for the polishing pad, measured with the use of a neutral solution is equal to or above −50 mV and less than 0 mV.
3. The polishing pad as claimed in claim 1 , wherein
a zeta potential of the polishing surface measured with the use of a neutral solution is equal to or above −50 mV and less than 0 mV.
4. The polishing pad as claimed in claim 3 , wherein
an underground layer is provided below a polishing layer comprising the polishing surface.
5. The polishing pad as claimed in any of claims 1 through 3 , wherein
an average surface roughness Ra of the polishing surface is equal to or above 1 μm and equal to or below 5 μm.
6. The polishing pad as claimed in claim 5 , wherein
an underground layer is provided below a polishing layer comprising the polishing surface.
7. The polishing pad as claimed in any of claims 1 and 2 , wherein
an underground layer is provided below a polishing layer comprising the polishing surface.
8. The polishing pad as claimed in claim 1 , wherein the largest amplitude is 10-40 μm.
9. The polishing pad as claimed in claim 1 , wherein the largest amplitude is a value measured in a distance range of 5-200 mm along the polishing surface.