Failure mechanisms of silicon-based atom-probe tips

Atom-probe (AP) analysis of silicon based samples frequently fail due to rupture of the tip. We have investigated the stability and failure mechanisms of silicon tips when prepared for AP analysis via Focused Ion Beam (FIB) milling. We observed four mechanisms that commonly lead to failure of the tips. These mechanisms are a deformation of the tips apex due to an interaction between the oxidized amorphous layer and induced mechanical vibrations, a rip off of an isolating oxide-layer, the rip off of a cap layer due to insufficient adhesion and a failure of the tip in the course of the analysis due to the rising voltage applied to the tip. In this paper we will discuss all four mechanisms show evidence of the causes of the breakdown and discuss options that allow avoiding tip failure.