One of the key concerns for CMP operations is maintaining close control over slurry quality particularly the particle size. Large aggregate size can have undesirable effects on removal rates, filter life and defect levels. A good understanding of the slurry behavior is thus very helpful in improving the CMP process reliability and reduction in cost of ownership. For metal CMP slurries containing a high concentration of ionic oxidizers, stability and aggregation issues are particularly important. The aggregation can be controlled to a large extent by the CMP distribution loop parameters such as agitation in the day-tank and th eturbulence during flow through the tubes. The emphasis of this paper is on how the agitation in day tan and the oxidizer affect the stability of Granite 14~(TM) slurry used for tungsten polishing. Bulk measurement techniques such as sedimentation rate measuremnets and diffuse light transmission have been used in this study to monitor the aggregate behavior in the slurry during agitation.
展开▼
