Adjusting the eddy current measurement

Abstract

The present invention describes, among other things, a method of controlling polishing during a polishing process. The method comprises the steps of: receiving, at time t, a measurement thickness(t) of a thickness of a conductive layer of a substrate undergoing polishing from an in-situ monitoring system; receiving, at time t, a measured temperature T( t); calculate the resistivity ρ of the conductive layer at the measured temperature T(t) T ; Calculate the resistivity ρ using T adjusting the measurement of thickness to generate an adjusted measured thickness; and detecting a polishing endpoint or an adjustment to a polishing parameter based on the adjusted measured thickness.

Description

technical field [0001] The present disclosure relates to chemical mechanical polishing, and more particularly to monitoring of conductive layers during chemical mechanical polishing. Background technique [0002] Integrated circuits are typically formed on a substrate by sequentially depositing conductive, semiconductive, or insulating layers on a silicon wafer. Various fabrication processes require planarization of layers on a substrate. For example, one fabrication step involves depositing a filler layer over a non-planar surface, and planarizing the filler layer. For some applications, the filler layer is planarized until the top surface of the patterned layer is exposed. For example, a metal layer can be deposited on the patterned insulating layer to fill trenches and holes in the insulating layer. After planarization, the metal forms vias, plugs, and wires in the remainder of the patterned layer's trenches and holes to provide conductive paths between the thin film c...

AI Technical Summary

Problems solved by technology

Thus, determining polishing endpoint based solely on polishing time can lead to intra-wafer or wafer-to-wafer non-uniformity

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