Papers by Author: S. Borsari

Abstract: 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.

Abstract: Tungsten is a metal widely used for interconnections. As a consequence of more stringent requirements in terms of aspect ratio deriving from device shrinking, the filling of W plugs is becoming more and more critical and new deposition techniques need to be employed to properly fill contacts and trenches. For example ALD nucleation layers need to be coupled to CVD deposition. Since physical-chemical properties of W are heavily influenced by deposition techniques, the effect of wet cleanings on different kind of W needs to be fully understood in order to avoid any kind of W corrosion or recession during wet cleaning with W exposed. In this paper the effect of several chemicals commonly used in BEOL wet cleanings for polymer removal, has been investigated on W films deriving from both CVD and ALD deposition techniques.