Patent ID: 6290572
Filing Date: 2001-09-18
Classification: B24B

Abstract:
In chemical-mechanical planarization of microelectronic substrate assemblies, a method for determining the status of a microelectronic substrate during a planarizing cycle comprising:determining an estimated value of an output factor that can be measured during the planarizing cycle without interrupting removal of material from the substrate by modeling the output factor based upon a predicted thickness of an outer layer over a first region on the substrate and an estimated erosion rate relationship based on a first erosion rate over the first region and a second erosion rate over a second region on the substrate;ascertaining an updated predicted thickness of the outer layer over the first region by measuring an actual value of the output factor during the planarizing cycle without interrupting removal of material from the substrate and calculating the updated thickness according to the actual value of the output factor and the estimated value of the output factor;repeating the determining procedure and the ascertaining procedure using the updated predicted thickness of the outer layer of an immediately previous iteration to bring the estimated value of the output factor to within a desired range of the actual value of the output factor; andcontrolling a process parameter of the planarizing cycle when the updated predicted thickness of the outer layer over the first region is within a desired range of a predetermined elevation for the substrate assembly.