3D Stacked Die Interconnect (14 nm Si Node)

Crossbeam laser FIB-SEM provides high quality imaging of microbumps and BEOL structures buried 860 μm deep in a 3D package; <1 hour total laser + FIB time.
ZEISS Crossbeam laser FIB-SEM is a site-specific cross-section solution enabling faster package failure analysis and process optimization.
Combined in the Crossbeam laser FIB-SEM is a fs-laser for speed, Ga+ beam for accuracy, and SEM for high-resolution imaging to enable the fastest workflows. The isolated laser chamber prevents contamination of the electron column and detectors from ablated materials, while ensuring sample integrity with easy transfer between the SEM and laser chamber under vacuum.
Fastest access to site-specfic buried features
The Crossbeam laser removes one cubic millimeter of Si with minimal artifacts in 30 minutes, compared to the days it would take other commonly used approaches. Integration of the laser and FIB into a single system and correlated workflows provide the fastest results and keeps the sample under vacuum.
Crossbeam laser FIB-SEM images microbumps buried 860 µm deep in <1 hour.
Minimal to no artifacts and best specimen quality
The Crossbeam laser workflow avoids mechanical polish artifacts such as delamination or cracks in fragile and stressed materials, while providing higher cross-section accuracy than mechanical cross sections.
Fs-laser ablation is athermal[1] so the laser affected zone (LAZ) is minimal, and it is often possible to image package interconnects immediately after laser ablation, without a need for FIB polish.
[1] K. Sugioka et al., doi:10.1038/lsa.2014.30
Cu-pillar microbump images taken directly after fine polishing using the fs-laser.
Backscattered electron (left) and secondary electron (right) images of Cu-pillar microbump after Ga-FIB polishing step.
Highest imaging performance with ablation contaminants segregated
The well-known imaging quality obtained with ZEISS Gemini electron columns are combined with an EsB detector for unique compositional contrast. The Crossbeam laser family has good performance for high quality analysis of insulating and low-contrast materials. Laser ablation is segregated from the main chamber to maintain high vacuum and clean chamber conditions for optimized imaging quality.
Samples can be easily shuttled back and forth under vacuum between the imaging and ablation chambers, ensuring a pristine sample protected from exposure to oxygen throughout the entire preparation and analysis sequence.