Advanced semiconductor packaging calls for advanced failure analysis solutions
Today’s semiconductors are a marvel to behold for anyone that appreciates intricate structures. For example, 2.5D and 3D packages contain multiple die types of hard and soft, insulating and conducting materials. Within each die bonded to interposers, substrates, or another die, high-density circuits and beam-sensitive materials coexist to create an increasingly sophisticated device.
While these devices enable superior performance, they also create a more challenging inspection, metrology, and testing environment. The ability to accurately target and remove materials in bulk without damage to sensitive regions of interest with high throughput is essential. In many cases, the region of interest (ROI) is a one-of-a-kind defect where the success rate needs to be at 100%.
Faced with these challenges, large volume analysis approaches have been developed to supplement the capabilities of a Focused Ion Beam (FIB) with a 1) standalone semiconductor ablation tool or 2) with an ablation laser in a second chamber accessible via a transfer portal. These solutions are effective for bulk milling, but both approaches have shortcomings when faced with precision failure analysis applications such as advanced semiconductor devices.
Sample navigation accuracy is limited when transferring a sample between a semiconductor ablation tool (either a stand-alone laser or one within a separate chamber) to a FIB. This error leads to larger processing times to reach the ROI. Since the initial laser-ablated cut-face is often as large as ~1 mm2, any error in its placement leads to additional large volumes the FIB must remove to selectively reach the ROI or defect. The maximum FIB current available is directly related to the removal rate making the plasma focused ion beam (PFIB) the preferred choice compared to the traditional FIB.
Making a DualBeam a TriBeam with integrated semiconductor laser ablation
To address current solutions’ deficiencies and provide flexibility in processing and analyzing a broad range of materials, Thermo Fisher Scientific has expanded its DualBeam product line with a fully integrated femtosecond laser in a single chamber.
Thermo Fisher Scientific Helios 5 Laser PFIB integrates a plasma focused ion beam (PFIB), a femtosecond laser, and a scanning electron beam in a single chamber for maximum throughput and precision. Furthermore, the three beams are at a single coincident axis for the highest throughput, success rate, and precision for semiconductor packaging failure analysis.
Benefits of a plasma beam, femtosecond laser, and single coincident axis
- Higher confidence in precisely navigating to the defect for laser ablation and final polishing for accurate and timely data collection for failure analysis.
- Material removal using the femtosecond laser is ~400 times faster than a PFIB and ~15,000 times faster than a Gallium FIB.
- PFIBs offer ~40x faster-milling speed than traditional Ga FIBs, allowing for quick and precise large cross-sectioning and clean-up post-laser ablation.
- Coincident axis allows for precision laser cut placement, PFIB milling, and imaging of large cross-sections in minutes without damaging sensitive ROIs/defects.
- Elimination of the need to transfer samples to a separate chamber or instrument significantly reduces processing time and sample contamination.
- Damage from the heat-affected zone is greatly diminished by using a laser pulse duration in the femtoseconds.
Available with Thermo Fisher’s Helios PFIB family, including the Helios 5 Laser PFIB, Helios 5 Laser Hydra and Helios 5 Laser, these instruments provide a new level of capabilities for large volume analysis of increasing complex structures.
To learn more about these solutions and how they enable high-volume bulk material removal, fine deprocessing, and imaging in one instrument, watch our on-demand SPARK webinar.
Adam Stokes is a product marketing manager at Thermo Fisher Scientific