Cmp system having an eddy current sensor of reduced height

Abstract

By providing an eddy current sensor element in a polishing tool at a reduced height level in combination with a corresponding optical endpoint detection system, standard polishing pads may be used, thereby enhancing the lifetime of the polishing pad and increasing tool utilization.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]Generally, the subject matter disclosed herein relates to the field of manufacturing integrated circuits, and, more particularly, to chemical mechanical polishing (CMP) process tools used for the formation of advanced metallization structures, such as so-called damascene structures, in which metal trenches and vias are formed in an insulating layer, while subsequently filling the vias and trenches with a metal and planarizing the structure by removing the excess metal using a polishing process.[0003]2. Description of the Related Art[0004]Typically, the fabrication of modern integrated circuits requires a large number of individual process steps, wherein a typical process sequence involves the deposition of conductive, semiconductive or insulating layers on an appropriate substrate. After deposition of the corresponding layer, device features are produced by patterning the corresponding layer with well-known means, such ...

AI Technical Summary

Benefits of technology

[0018]Generally, the subject matter disclosed herein is directed to CMP tools and related components, such as polishing pads, sensor components and the like, which enable an in situ monitoring of the polishing process, wherein at least an inductive sensor may be provided that generates a signal related to the amount of conductive material formed on a surface to be treated. As previously explained, in highly advanced CMP tools, typically optical process control and process control based on inductive sensor concepts, for instance using the eddy current principle, may be provided concurrently in order to enhance controllability and flexibility of the respective CMP tools. In these conventional CMP tools, sophisticated polishing pads may have to be used including extra thin pad windows for enabling both efficient optical coupling and efficient inductive coupling. Due to the sophisticated design of the respective polishing pad, significantly increased cost of ownership may be encountered, in particular as reduced lifetime of the corresponding window portions may require more frequent replacement of a polishing pad. In illustrative embodiments disclosed herein, a respective inductive sensor is provided that is appropriately designed to enable the usage of pad windows of increased thickness and / or standard polishing pads as are typically used in optical endpoint detection systems of CMP tools without additional eddy current sensor elements, thereby increasing the overall lifetime of the polishing pad.

Problems solved by technology

Due to the sophisticated design of the respective polishing pad, significantly increased cost of ownership may be encountered, in particular as reduced lifetime of the corresponding window portions may require more frequent replacement of a polishing pad.

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