Using exclusion ring technology to avoid CVD tungsten bevel contamination

摘要

The tungsten chemical vapor deposition (WCVD) process has been used in manufacturing semiconductor devices for many years. Because of its excellent step coverage, tungsten is used to fill high-aspect-ratio contacts and vias in logic and memory devices. Its use as an interconnect material in memory devices is driven by its superior electromigration properties. The inherent low resistivity of tungsten has fostered the emergence of new applications using this material, including advanced memory devices in which both bit and word lines will be made of tungsten.