Patent ID: 6991516
Filing Date: 2006-01-31
Classification: B24B

Abstract:
1. A method of chemical mechanical polishing a layer that covers an underlying surface on a substrate, comprising: polishing the layer at a first polishing station and applying a first plurality of pressures to a plurality of regions of the substrate; monitoring a plurality of portions of the substrate during polishing at the first polishing station with a first in-situ monitoring system; determining a plurality of thicknesses based on measurements by the first in-situ monitoring system; calculating in a closed-loop control system the first plurality of pressures to apply to the plurality of regions of the substrate; determining whether a representative thickness of the layer is less than a threshold thickness; and if the representative thickness is less than the threshold thickness, halting calculation of pressures by the closed-loop control system and applying a plurality of first predetermined pressures to the plurality of regions of the substrate.