Study of FIB milling induced damage and contamination on ex-situ lift-out TEM specimen and methodology to reduce the artifacts

Conventional FIB ex-situ lift-out is the most common technique for TEM specimen preparation. However, the FIB milling induced artifacts limit the TEM image quality. By a novel double cross-sectional lamellae preparation, the sidewall amorphous layers were studied. It was noted excess damage layer and additional redeposition layer were observed on different side of TEM specimen, which induced by ion beam irradiation and redeposition of sputtered material respectively when cutting the TEM specimen free from trench at 0 degree stage tilt. By the bottom cut-first FIB method, the damage layer and redeposition layer were therefore reduced. Real TEM cases have shown that the method offers better TEM image quality compared to that of the samples prepared by normal FIB procedures, while maintaining high TEM sample preparation throughput.