Polishing pad methods of manufacture and use

Abstract

The present invention is directed to polishing pads useful in determining an end to the useful wear life thereof. In a simple embodiment of the present invention, a polishing pad that is used with slurries is dyed on one side in a manner that causes the dye to permeate the pad to a limited depth that does not cause total coloring. Another embodiment of the present invention involves a fixed abrasive pad that has fixed abrasives embedded into the pad to a selected depth where at least one color level is within the portion of the pad that contains the fixed abrasives. After dyeing the pad, the pad is attached to the polishing platen. During the polishing operation, a color change signals a time to stop the polishing operation and change the pad. With multiple colors in the pad, limited only by the ability to dye the pad with uniform depth levels, characteristic wear patterns can be observed and adjustments made accordingly to prolong and optimize pad life. A pad having voids and optional abrasives incorporated therein is also disclosed. The contents of each void facilitates the detection of the degree to which the polishing pad has been worn during a polishing operation. Substances may be stored within voids that are released by the breach of the voids caused abrasion during the polishing operation. Visual or audible diagnostics resulting from the breaching of voids are useful to control the polishing operation and thus increase yield.