A high-speed transmission electron microscope was developed for probing laser-induced fast nonperiodical processes on the nanosecond time scale. 7–11 ns illuminating electron pulses—up to three—are produced by a laser pulse-driven photocathode. The electron gun can be used both for nanosecond exposure and conventional stationary operation. The introduced microscope is operated in three different modes for investigations of laser treated thin films: (1) Bright-field imaging, tracking changes of the texture and transport of neutral material; (2) dark-field imaging, mapping transient plasmas; and (3) selected area diffraction to study fast phase transitions. Presently, the space resolution is ≈200 nm.

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Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

In this paper we introduce novel tools for an improved failure analysis process flow for complex packaged microsystems. This failure analysis process flow starts with a non-destructive defect localization using an improved Lock-In Thermography (LIT). After fault isolation, a highly efficient target preparation can be performed using cross-sectioning by combined pulsed-laser ablation and high-current Focused-Ion-Beam (FIB) milling in a specifically modified FIB device. The sample quality achieved is high enough to enable improved high-resolution material analysis of cross-sectioned structures using Scanning Electron Micrography (SEM) and Electron Back-Scatter Diffraction (EBSD), particularly for the analysis of highly resistive bonding interconnects, intermetallic compound identification, and texture analysis. To illustrate the complete workflow of the approach, a failure analysis of a vertically integrated microsystem using a microinsert technology is described. The particular benefit of each step is compared to conventional approaches in failure analysis. In addition, the potential of the new failure analysis methodology for future applications using System in Package (SiP) technologies is highlighted. Failure analysis workflowTechnologies for the assembly of complex SiP solutions and 3D integration as well as for embedding of active and passive components into built-up layers of substrates have attracted increasing attention during recent years. In addition to the technological aspects, the reliability properties are also of paramount importance.Due to these new systems' complex designs, dimensions, and materials, traditional failure-analysis methods established for semiconductor front-end technologies are either not applicable or have to be adapted to the specific requirements of SiP and 3D integration technologies. The need for failure identification in stacked or buried components has to be taken into account, including information on vertical fault position and the broad variety of material combinations involved. Thus, it is essential to develop new methods to detect reliability-limiting or failed structures in highly integrated systems. These methods must be able to be applied during technology development, quality testing, reliability assessment, and failure analysis of field returns. The paper aims at demonstrating novel tools that can be implemented into a stepwise fast and efficient failure analysis process flow for complex integrated microsystems. In the first section of the paper, we show the application of non-

The ablation of chromium films by nanosecond laser pulses was tracked by triple-frame high-speed transmission electron microscopy and selected area diffraction (exposure time ≈7–11 ns, frame spacings 20 ns–10 μs). At lower fluences the films were shattered during heatup and cooldown, producing debris with huge in-plane accelerations up to 1010 m/s2 and rotations with 106 rps. At higher fluences the ablation is proceeded by a domain-patterned evaporation. These effects are responsible for the high damage in laser-produced patterns in chromium films. They were all explained as being due to stress waves, launched by an extremely fast nonthermal 3%–4% expansion/contraction of the bcc lattice constant during heating/cooling.