Soft and conditionable chemical mechanical polishing pad with window and method of polishing substrate

A wedge clamp includes a top wall, a bottom wall, a front wall, a rear wall opposite the front wall, and a fluid port traversing from the front wall to the rear wall. The fluid port has a front opening and a rear opening to allow cooling fluid to pass therethrough. In one embodiment, the front opening is a rounded isosceles trapezoid in shape with a pair of parallel substantially planar side walls of different length and a pair of arcuate side walls connecting the pair of planar side walls. The rear opening has a greater surface area proximate the rear wall and a smaller surface area proximate the front opening, resulting in a funnel-shaped opening to cause an increase in velocity of the cooling fluid passing through the fluid port.