Multipurpose sample holder for advanced Transmission Electron Microscopy (TEM) sample preparation which reduces cost of the tool and most importantly simplifies the workflow is introduced. Following the current demand for user-friendly interface, semi-automated approach is aimed to be build up. Abilities to prepare advanced TEM lamellae in various geometries without rotary nanomanipulator and using various end-point detection signals are perceived as biggest advantages of this design.

An advanced sample preparation protocol using Xe+ Plasma FIB for increasing FA throughput is proposed. We prepared cross-sections of 400 μm and wider in challenging samples such as a BGA (CSP), bond wires in mold compound or a TSV array. These often suffer from FIB milling artifacts. The unsatisfactory quality of the cross-section face is mainly due to extremely different milling rates of the various materials (polyimide, tin, copper, mold compound, platinum), ion beam induced ripples [1] or due to significant surface topography. We explored the usability of the protocol for standard cross-sections and also tested the preparation of TEM lamellae. The process parameters of the proposed approach were compared with the standard methods of Xe+ Plasma FIB FA with respect to preparation time and cross-section quality. Aiming for ultimate results, we incorporated the Rocking stage technique which also greatly improves cross-section quality.

High speed FIB cross-sectioning of polyimide material was traditionally very difficult because of artifacts created by FIB on the cross section plane. Therefore we propose a simple method, which retains the high speed of the FIB process, but significantly improves the quality of the cross section plane. The method involves a hard mask positioned close to the intended place of the cross section using a precise manipulator. This then enables highly accurate and site-specific FIB cross-sectioning. Cross sections can be made very quickly and with the excellent quality in comparison to standard procedures based on gas-assisted deposition of a protection layer.

Reducing FIB induced damage on TEM samples is very important in order to preserve the sample structure, especially on modern semiconductor devices. We have compared the damage caused by Ga ion beam to our measurements of the damage caused by Xe ion beam and came to the conclusion that Xe ion beam induced damage is significantly lower at 30 keV beam energy. This has been proven by several independent analytical methods. Our results show that TEM sample preparation by Xe ion beam causes less amorphous damage and increase the quality of the lamella and in many cases it will allow to prepare the lamella by finishing it even at 30 keV, without the final cleaning step at the low beam energy. Final polishing step by Xe beam at beam energy 3 keV further reduces the amorphous layer, but the difference against Ga beam is not so significant like at 30 keV.

Cross sections of large Through Silicon Vias (TSV) and solder bumps are often prepared using the Focused Ion Beam (FIB). The high current Xe plasma ion source allows fast and precise target preparation of TSV with small diameter. Solder bumps can be accessed due to the high milling rate too. However, the high current milling by plasma FIB causes the worsening of the milled surface quality. An optimized FIB scanning strategy accompanied with the novel rocking stage for the sample tilting during the milling has been developed for the plasma FIB. Whole milling process is observed by the Scanning Electron Microscopy (SEM). Time to prepare a cross section is accelerated and the excellent quality is suitable for subsequent failure analysis. Also important is proper sample cleaving before FIB milling. Using an accurate method to cleave the sample prior to FIB preparation further reduces the overall sample preparation time. The high quality cross sections prepared using this new method are ready not only for SEM but also for EDX and EBSD analysis, either 2D or 3D, when combined with FIB slicing. Broadening the analysis to these techniques increases the obtainable information, allowing the arrangement of materials and their crystalline structure to be studied in a detail.

3D tomography of TSVs was performed by combining Xe plasma FIB milling and lift-out techniques. This approach allows analyzing the structure of TSVs in detail using a method faster than the usual 3D tomography by Ga FIB and more precise than X-ray tomography. Both well-filled TSVs and TSVs with voids were analyzed and the results were compared. The analysis procedure was optimized in order to reduce the analysis time and to increase the throughput. The lift-out of the analyzed block of material was performed to obtain 90° angle between TSV and the ion beam axes, which is critical to reduce the curtaining effect and which allowed to increase FIB beam current significantly, reducing the analysis time.