Methods and apparatuses for monitoring and controlling mechanical or chemical-mechanical planarization of microelectronic substrate assemblies

Abstract

Methods and apparatuses for mechanical and/or chemical-mechanical planarization of semiconductor wafers, field emission displays and other microelectronic substrate assemblies. One method of planarizing a microelectronic substrate assembly in accordance with the invention includes pressing a substrate assembly against a planarizing surface of a polishing pad at a pad/substrate interface defined by a surface area of the substrate assembly contacting the planarizing surface. The method continues by moving the substrate assembly and/or the polishing pad with respect to the other to rub at least one of the substrate assembly and the planarizing surface against the other at a relative velocity. As the substrate assembly and polishing pad rub against each other, a parameter indicative of drag force between the substrate assembly and the polishing pad is measured or sensed at periodic intervals. The measured drag force can be used to generate a plot of work versus time. The work versus time plot is then integrated to determine an estimated work exerted at the pad/substrate interface. The planarizing process is terminated when the estimated thickness is at least approximately within a range of desired substrate assembly thickness for endpointing the substrate assembly according to a predetermined relationship between work and substrate assembly thickness.