CUSHION FOR POLISHING PAD AND POLISHING PAD USING THE CUSHION

摘要

This invention provides a polishing pad that can achieve polishing which can realize excellent flatness of a polished surface and evenness of the film thickness after polishing, and, at the same time, can realize a high polishing rate, and also has excellent polishing evenness of a polishing object such as an insulating film or a metallic film, and a cushion using the polishing pad. The cushion satisfies the requirements that, in the measurement of the dynamic compression viscoelasticity under conditions of 23°C, static load 27.6 kPa, frequency 11 Hz, and amplitude 1 µm, (1) the difference in phase between dynamic stress and deformation is not more than 4 degrees, and (2) the ratio of the maximum value of the deformation to the maximum value of the dynamic stress ([maximum value of deformation]/[maximum value of dynamic stress]) is not less than 0.5 µm/kPa. The polishing pad comprises the cushion layer for a polishing pad and a polishing layer.