Observation of submicronic contacts and vias by scanning ion and electron microscopy

Scanning ion and electron microscopy of focused ion beam cross-sections has been used to observe 0·6 μm contacts and 0·7 μm vias of a 0·5 μm CMOS technology. Three different kinds of cross-sections have been tested to improve the observation quality. The comparison of images obtained with ions and electrons provides information on ion and electron contrast mechanisms. This technique has been used to identify very small defects in interconnection structures and to evaluate the 0·5 μm CMOS metallization process.