Using Nano-Probing Technique to Clarify Nickel Silicide beyond Process Window Causing Device Failure

摘要

A scanning electron microscopy (SEM) based nano-probing system is used in this study to clarify nickel silicide phase beyond process window. According to the nano-probing measurement result and the cross-sectional transmission electron microscopy (TEM) images, phenomena of junction leakage along with high resistance and a larger nickel silicide area are observed at failure site at the same time. The type of failure mechanism and in-line process issue caused multiple failure phenomena at failure site will be the major focuses in this paper. Nickel silicide phase transformation from NiSi to NiSi_2 is highly suspected by the comparison of sheet resistance and silicon consumption. Consequently, nickel silicide beyond process window could be verified immediately.