Post-FIB Cleaning of TEM Specimens from 14 nm and Other FinFETs by Concentrated Argon Ion Milling

TEM specimens prepared using a Ga FIB are susceptible to artifacts, such as surface amorphization and ion-implanted layers, that can be problematic in advanced technology nodes, particularly for FinFETs. As this article shows, however, post-FIB cleaning via concentrated argon ion milling makes for a fast and effective specimen preparation process for FinFET devices controlled to a thickness of less than 20 nm. Although the results presented here are based on 14 nm node FinFETs, the method is also applicable to the 10 and 7 nm FinFET technologies currently in production.