Tungsten oxidation kinetic after wet cleaning: XPS and ToF-SIMS Characterization

摘要

Tungsten importance in semiconductor manufacturing is renewed more and more due to its usage not only as metallization for plugs, but also in metal gates architectures. As the scaling down of the devices is becoming aggressive, the metal interfaces become more critical. Hence, a deeper understanding of the evolution of the W surface after wet cleaning processes is becoming increasingly more important. In this paper we have characterized the oxidation kinetic of tungsten deposited with different techniques after cleaning with several products commonly used as BEOL polymer removers. The surfaces have been analyzed both with XPS and ToF-SIMS, in order to characterize not only the kinetic of the oxidation, but also the kind of the oxide formed on the surface.