Abstract: The techniques of the present invention facilitate the control of an IC chip fabrication level of a fabrication process based upon the design pattern of the IC chip being fabricated. A grid having multiple sections is imposed over the design pattern of a fabrication level of the IC chip. Then, pattern density values are automatically established for the design pattern contained in each section of the grid. The IC chip fabrication level is then controlled based upon the pattern density values. For example, the established pattern density values facilitate the automatic determination of a CMP process stop parameter, or the automatic compensation for etch rate variations caused by pattern density differences across the design pattern of the IC chip.

Abstract: An apparatus and method for determining a selected endpoint in the polishing of layers on a workpiece in a chemical/mechanical polishing apparatus where the workpiece is rotated by a motor against a polishing pad. When a difficult to polish layer, i.e., one requiring a chemical change in a surface skin of the layer which skin is then abraded away by a mechanical process is removed from a more easy to polish surface, i.e., one that relies solely on mechanical abrasion and does not need to have a chemically converted skin thereon. The power required to maintain a set rotational speed in a motor rotating the workpiece significantly drops when the difficult to polish layer is removed. This current drop is used to detect the point at which the polishing must be stopped to avoid over polishing effects, i.e., dishing or thinning or removal of the more easily removed underlying material. Thus, an end point in the process can be established.