Comparative study of the lubricating behavior between 12-in. copper disk and wafer during chemical mechanical polishing

In this study, a specially designed carrier with a one-zone pneumatic loading system that uses a thick copper disk as the workpiece was developed. Comparative studies of the fluid pressure and workpiece orientation between the disk and wafer carriers during chemical mechanical polishing were conducted. The results reveal that the copper disk leans down toward the leading edge and produces a negative-dominated (approximately 70%) fluid pressure, which differs from the multi-zone carrier but agrees with other studies in which the fluid pressure is measured from the disk side. Different balancing statuses and wedged gaps are formed in these two structures.