As the semiconductor industry moves toward advanced nodes and complex 3D architectures, traditional Failure Analysis (FA) workflows often fall short due to time-consuming inter-instrument transfers, environmental contamination risks, and poor contextual continuity and spatial resolution. To address these limitations, we introduce a correlative, in-situ methodology that integrates Atomic Force Microscopy (AFM) directly into the vacuum chamber of a Scanning Electron Microscope (SEM) or Focused Ion Beam (FIB) platform.
This work particularly focuses on the combination of plasma FIB (PFIB) delayering with subsequent in-situ Conductive AFM (C-AFM) analysis performed under consistent vacuum conditions. The dual-beam configuration enables real-time switching between milling and probing modes, eliminating contamination risk. As a result, reproducible current and I/V spectroscopy measurements are acquired at identical regions of interest (ROI) across device layers.
The workflow is demonstrated on 3D NAND memory cells, where sub-50 nm features were probed without compromising the surface integrity. After deposition of a protective tungsten layer using a gas injection system, PFIB delayering was performed while the AFM probe was retracted to prevent material redeposition. Automated navigation based on SEM imaging and compatible navigation files enabled precise positioning of the AFM tip at the ROI, followed by sequential SEM and C-AFM imaging. This process was repeated to obtain depth-resolved electrical information from the same device.
The introduced in-situ approach enables efficient and reliable correlation of structural and electrical properties and is particularly beneficial for FA of complex devices such as SRAM, logic structures, vias, and interconnects. Ongoing developments, including electron-beam induced C-AFM [1], further extend the analytical potential of this methodology for advanced semiconductor FA.
We would like to thank Libor Strakos from Thermo Fisher Scientific, Brno, and Umberto Celano from Arizona State University for their support.
