Size distribution of these particles is shown in Fig. 5. EDX data indicates that these samples primarily included the elements carbon, oxygen, silicon, and aluminum, with silicon representing a larger fraction than aluminum. However, as silicon is often the subject of abrasion in CMP, further study will be necessary to concretely demonstrate that these particles originate in the CMP slurry versus being generated as a byproduct of the process. Such a study might be conducted using a system in which silicon-containing slurries are not used, thus eliminating the slurry as a source for any observed silicon in the waste.