to induce a controlled flex in the polishing layer to conform to the global topography of the wafer surface while maintaining a controlled rigidity over the local topography of the wafer surface application_number US 87482392 A description referring now to fig6 a polishing pad 50 having a polishing layer 52 a rigid layer 54 and a resilient layer 56 according to the present invention is shown the polishing pad so is designed to operate in the polishing apparatus 20 of fig4 the three layers are bonded together and to the platen 21 of polishing apparatus 20 with adhesives which are well known in the art the elements which perform the same or similar function as described with reference to fig1 5 are indicated by the same reference numerals in fig6 polishing layer 52 is composed of a material having good polishing characteristics such as urethane or composites of urethane and other materials the polishing layer 52 is also thin and relatively incompressible in a preferred embodiment of the present invention polishing layer 52 should be no more than 0 003 inches thick and have a compression modulus in the range of 600 to 2000 pounds per square inch a polishing layer 52 of different thickness may be used provided the polishing layer material used has a compression modulus which compensates for the difference in the thickness of the layer rigid layer 54 provides a backing of controlled rigidity to the polishing layer 52 the rigid layer 54 should be made of a material which is resistant to chemical attack by.