Patent ID: 7871309

Claim:
A polishing pad having a polishing region and a light-transmitting region, wherein a water permeation preventive layer is provided on one surface of the polishing region and the light-transmitting region, and the light-transmitting region and the water permeation preventive layer are made of the same material integrally in a single piece, wherein each of the polishing region and the light-transmitting region comprise a polymer made from raw materials on equipment that comprises surfaces contacting said raw materials, wherein said surfaces comprise no metal other than chrome such that each of said regions have a concentration of Fe of 0.3 ppm or less, a concentration of Ni of 1.0 ppm or less, a concentration of copper of 0.5 ppm or less, a concentration of zinc of 0.1 ppm or less and a concentration of Al of 1.2 ppm or less.