February_EDFA_Digital

edfas.org ELECTRONIC DEVICE FAILURE ANALYSIS | VOLUME 21 NO. 1 40 of Xe FIB). Pradip Sairam Pichumani, GlobalFoundries, presented several techniques to improve the quality of the final polished face including manual rocking and the use of a shadow mask made of a small piece of silicon. Discussions also included various stage rocking methods and pretilted sample holders, tungsten and multilayer pre-deposition, and defocusing to use the very edge of the beam tail. A novel suggestion by Becky Holdford, TI, retired, was discussed as well. It is best described as a “pseudo-inverted type” polishingmethod she developed using the tilt for finishing large wirebond sections from the bottom. T his year the Contactless Fault Isolation and Nanoprobing User Group included a wide variety of discussions. Fourteen topics were covered including: lock-in thermography, 3D packaging technol- ogy impact on probing, challenges for sample prep, cross sectional nanoprobing, and EBIRCH techniques at the advanced technology nodes. Further topics in the areas of VLP use and experiences, laser-based techniques includ- ing TIVA, pulsed IV nanoprobing, reliability and end-of-life nanoprobing, extended temperature range probing (-40°C toextremelyhighpower debug), LVPoptical crosstalk, SEM beam damage during nanoprobing at advanced technol- ogy nodes, and lastly threshold voltage shifts encountered during debug, were also discussed. Numerous comments came fromthe audience ofmore than 90 attendees during the discussion period. Sample prep for nanoprobing and VLP (577 nm/785 nm) was a hot topic and all agreed it is one of the biggest challenges as the process shrinks to 7 nm and beyond. In addition, concerns were raised about debug at lower temperatures because increasing power density is a big challenge for smaller silicon footprints. The urgency to come upwith newcooling solutionswas voiced. For nano- probing, the plasma FIB is being used to achieve uniform and quicker results for sample prep. The idea of adding an argon ion gun to clean the contacts after delayering was alsodiscussed. For reliability and end-of-life nanoprobing, attendees commented that it could be useful in helping both foundry anddesign to check if simulationsmatch the post-Si data, and could also be a goodway to confirmthat real life aging matches the nanoprobing stress. All topics were well received with active discussions and Q&A. Each one included the issues and challenges being faced in the contactless probing and nanoprobing areas, and follow-up discussions helped raise pertinent questions and concerns about how the industry canmove forward. With the introduction of the online user group forum this year, we hope to continue the efforts to tackle these issues and other challenges throughout the year and keep the discussion active. We look forward to a great 2019 user group meeting as well. ISTFA 2018 CONTACTLESS OPTICAL/NANOPROBING EFA USER GROUP Chair/Co-Chairs: Dan Bockelman, Sweta Pendyala dan.bockelman@intel.com, sweta.pendyala@globalfoundries.com F or the Sample Prep User Group forum, more than 80 people attended fromvarious companies to interact and discuss the issues, bottlenecks, and interesting processes involved in sample preparation. The modera- tor provided various primer topics to get the audience involved and allow the interaction to begin. Highlighted below are the topics covered during the meeting. ISTFA 2018 SAMPLE PREP USER GROUP Chair: Jim Colvin admin@fainstruments.com The first topic discussed was methods and different approaches for quickly removing the overmoldonmolded packages to access capacitors for further FA. Use of laser ablation followed by periodic x-ray imaging to determine the proximity of exposure to the start of the capacitorswas outlined. Use of fuming H 2 SO 4 with an eye dropper was broached. Kapton tape used around devices to prevent