Patent ID: 6682628
Filing Date: 2004-01-27
Classification: B24B,H01L

Abstract:
A machine for planarizing a microelectronic-device substrate assembly, comprising:a table having a bearing surface; a polishing pad having a planarizing zone positioned over the bearing surface of the table, the polishing pad having a backside supported by the bearing surface and a planarizing surface in a planarizing plane; a carrier assembly for controlling a substrate assembly, the carrier assembly having a head configured to hold the substrate assembly against the planarizing surface; a drive system having a shaft pivotally coupled to one of the carrier head or the table to move at least one of the table or the carrier head in a lateral movement at least generally parallel to the planarizing plane to impart relative lateral motion between the substrate assembly and the polishing pad thereby generating lateral drag forces; and an endpointing system including a force detector attached at a load site to at least one of the carrier head or the table, a computer readable medium programmed with a predetermined relationship between work exerted at a pad/substrate interface and thickness of the substrate assembly, and a computer programmed with an integration function being coupled to the force detector and the computer readable medium, the force detector being positioned at the load site to provide signals indicative of lateral drag forces to the computer, the computer integrating the product of the drag force signals and relative velocity over time to determine an estimated work exerted at the pad/substrate interface, and the computer correlating the estimated work with the predetermined relationship between work and substrate assembly thickness to ascertain an estimated thickness of the substrate assembly.