Silicidation using nickel and Dysprosium stack on Si(100): NiSi 2 formation and impact on Schottky Barrier Height

Abstract

High contact resistance R c at the silicide/semiconductor interface could limit the drive current in Field Effect Transistors (FETs) at sub-22 nm technology nodes. 1 For n-channel FETs, lowering the effective electron Schottky Barrier Height B n at the silicide/semiconductor interface will reduce R c. Incorporating rare earth materials such as Dysprosium (Dy) during nickel silicidation to form Ni-Dy alloy contacts 2 has been reported to lower B n. Previously, the B n lowering was attributed to the formation of a Dy-rich interlayer between the silicide and semiconductor. In this paper, we report new findings that NiSi 2 formation is the main reason for the reduction in B n for Dy-incorporated Ni silicides. © 2011 IEEE.