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Viewing Asperity Behavior Under The Wafer During Chemical Mechanical Polishing, Caprice Gray, Daniel Apone, Chris Rogers, Vincent Manno, Chris Barns, Mansour Moinpour, Sriram Anjur, Ara Philipossian

Vincent P. Manno

Recent experimental advances using dual emission laser induced fluorescence and image processing have provided high spatial and temporal resolution maps of the slurry layer during chemical mechanical polishing (CMP). Intensity differences in the images correspond to fluid layer thickness variations as the slurry passes between different pad and wafer topographies. Asperities expand under 14 μm deep wells and are compressed beyond the trailing edge of the wells. Air pockets travel from the leading to the trailing edge of the wafer through 27 μm deep wells. The pads tested were Freudenberg FX9, Rodel IC1000, and experimental pads from Cabot Microelectronics.