Use of focused ion beam sample preparation for Auger analysis

Abstract

Abstract FIB cross‐sections are often used to get access to sample features of interest. Due to the inherent surface sensitivity an AES measurement is favourable for small feature compositional analysis on such samples. Even though the primary electron beam diameter of a modern field emission AES instrument is about 30 nm and thereby nearly ten times that of a SEM, the analysis volume of an AES measurement is much smaller than that of SEM/EDX. As AES measurements on small sample features can last for many hours it is mandatory to compensate a likely mechanical drift. In this procedure at regular intervals SE images are compared with an SE image recorded at the beginning of the measurement. Lateral drifts are compensated by an additional electrostatic deflection of the primary beam. For this purpose on low contrast samples or samples with periodically repetitive structures a FIB crater cut into the sample surface can be successfully applied as a marker feature to determine sample drift. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)