Helios MX1 PFIB-SEM Techniques

Semiconductor analysis techniques enabled with the Helios MX1 PFIB-SEM

Learn how the Thermo Scientific Helios MX1 PFIB-SEM, with its multi-ion species plasma FIB, ultra-high-resolution SEM, and integrated metrology with 3D reconstruction, can provide the process control insights you need with automated workflows to maximize your efficiency for metrology and defect analysis.

Overcoming in-line metrology limits with diagonal milling

This technique enables rapid and precise nanometer-scale through- stack measurements of critical device structures across 300 mm wafers—data inaccessible to traditional in-line metrology. Used in memory devices like 3D NAND and DRAM, it reveals CD trends through the device height, providing statistically valid process feedback. Diagonal milling uses the Helios MX1 PFIB-SEM’s high-throughput argon plasma source to reveal buried features along a sloped cut, allowing CD measurements at defined heights.

 

Engineers can quickly assess etching quality, bowing, twisting, and CD variation, improving fab process control and performance optimization.

Diagonal milling through 3D NAND layers providing nanometer-scale CD information directly from 300 mm wafers.

Precise delayering for high-resolution SEM

Using proprietary gas chemistry and the xenon plasma source, the Helios MX1 PFIB-SEM enables precise, large-area planar delayering of 3D NAND memory cell arrays at the wafer level. This allows for high-resolution SEM metrology directly in the fab, accelerating feedback and high-volume data collection. With automated end-pointing, material is removed and tracked, allowing precise layer by layer mill control capturing thousands of through stack CD measurements per memory cell. This supports comprehensive statistical analysis of key metrics like bow CD, twist, eccentricity, shape, and taper, enhancing process control and performance evaluation.

Delayering to measure CDs of the memory cell array at target layers.

High-throughput cross-sectioning and automated metrology workflows

The Helios MX1 PFIB-SEM enables high-throughput cross-sectioning of structures like through-silicon vias (TSVs) directly on 300 mm wafers using an argon plasma ion beam. Integrated metrology software provides automated measurements, delivering high-resolution SEM metrology data within the fab. This streamlined workflow significantly shortens the time to actionable data and accelerates the process feedback loop.

TSV cross sectioned using the argon ion beam enabling precise measurements.

Wafer level defect analysis with high-throughput cross-sectioning

Advanced packaging interconnects are becoming more complex. Micro-bump and hybrid bonding technologies remain key to 3D packaging. Consequently, defects are often introduced in R&D and manufacturing. Wafer-level root cause analysis avoids breaking wafers to characterize defects such as misalignment, particles, and voids, speeding up yield ramp. The Helios MX1 PFIB-SEM’s large-volume-removal argon plasma FIB quickly exposes cross-sections, and high-resolution SEM imaging reveals defect causes, helping address TSV fabrication and wafer stacking challenges efficiently.

Micro-bump cross sectioned to reveal defects

3D characterization including virtual slice metrology and buried defect analysis

Multi-scale 3D analysis is often essential for uncovering buried defects and visualizing structures that would otherwise remain hidden. The Helios MX1 PFIB-SEM enables fast, precise, and efficient serial sectioning of large volumes using argon plasma milling, followed by high-resolution SEM imaging at the nanometer scale. The resulting datasets can be processed to generate detailed 3D reconstructions that reveal structural interfaces and defects. Additionally, for metrology applications, virtual slices can be extracted from the 3D volume.

 

This technique provides direct, through-volume insight into individual NAND channel diameter, eccentricity, and shape, including overlay and inter-deck etch alignments, providing statistically relevant multi-channel trends.

3D volume reconstruction with virtual slice metrology.
3D volume reconstruction with virtual slice metrology showing channel x-position vs. depth

For Research Use Only. Not for use in diagnostic procedures.