A planarization monitor has been applied to the copper system to investigate pattern dependencies during copper overburden planarization. Conventional profilometry and a noncontact, acousto-optic measurement tool, the Insite 300, are utilized to quantify the planarization performance in terms of the defined step-height-reduction-ratio (SHRR). Illustrative results as a function of slurry, pad type and process conditions are presented. For a typical stiff-pad copper CMP process, we determined the planarization distance to be approximately 2mm.