Four-dimensional scanning transmission electron microscopy (4D-STEM) is a spatially resolved electron diffraction technique that records the electron scattering distribution at each point of the electron beam raster, thereby producing a four-dimensional dataset. The final article in this series covers ptychography, a form of computational imaging that recovers the phase information imparted to an electron beam as it interacts with a specimen.

Four-dimensional scanning transmission electron microscopy (4D-STEM) is a spatially resolved electron diffraction technique that records the electron scattering distribution at each point of the electron beam raster, thereby producing a four-dimensional dataset. This second installment of this series presents applications of 4D-STEM, including measurements of crystal orientation and phase, short- and medium-range order, and internal electromagnetic fields.

Four-dimensional scanning transmission electron microscopy (4D-STEM) is a spatially resolved electron diffraction technique that records the electron scattering distribution at each sampling point. 4D-STEM provides researchers with information that can be analyzed in a multitude of ways to characterize a sample’s structure, including imaging, strain measurement, and defect analysis. This article introduces the basics of the technique and some areas of application with an emphasis on semiconductor materials.

This is the story of how the mainstream Omniprobe FIB lift-out solution was invented and delivered to the market.

This article discusses sample preparation challenges that have impeded progress in producing bias-enabled TEM samples from electronic components, as well as strategies to mitigate these issues.

This article discusses the tradeoffs associated with minimizing beam dose in a scanning transmission electron microscope (STEM) and explains how to reduce beam exposure through subsampling and inpainting, a signal reconstruction technique that optimizes image quality and resolution. Although the method is described in the context of STEM imaging, it applies to any scanned imaging system.

This article provides a brief overview of STEM-in-SEM, discussing the pros and cons, recent advancements in detector technology, and the emergence of 4D STEM-in-SEM, a relatively new method that uses diffraction patterns recorded at different raster positions to enhance images offline in selected regions of interest.

This Master FA Technique column describes an easy and inexpensive solution to the problem of preparing TEM cross-sectional samples from etched wafers with large aspect ratio vias.

Long-term stability studies indicate that cathode degradation is one of the main failure mechanisms in anode-supported SOFCs. In order to better understand the microstructural degradation mechanisms of the cathode and the influence of oxygen partial pressure at relevant operating temperatures, the authors of this article acquired TEM samples from technological cells to study cation interdiffusion mechanisms and LSM-YSZ interactions, particularly in areas where LSM grains are in contact with YSZ electrolyte. Here they present and interpret the results.

The ability to discern the composition and placement of atoms in a sample makes TEM one of the most powerful characterization tools for microelectronic components. For many devices, however, the dynamics underlying normal operation do not displace atoms. Device function is, instead, mediated by electronic and thermal processes that have little effect on physical structure, necessitating additional tools to determine the causes of failure. In this article, the author presents results indicating that STEM EBIC, with the new SEEBIC mode, can provide electronic contrast that complements the physical-based contrast of STEM imaging. By identifying device features at higher risk of failure, the two methods may open a path to predictive failure analysis.

Three case studies involving 14 nm SRAM technology show how progressive FIB cross-sectioning and top-down analysis can be supplemented with nanoprobing and TEM tomography to determine the root cause of failure. In the first case, the memory failure is traced to an abnormal gate profile. In the second case, the failure is attributed to a metal line short, and in the third case, a gate defect.

This article describes an ebook titled STEM-in-SEM: Introduction to Scanning Transmission Electron Microscopy for Microelectronics Failure Analysis , intended as an introductory tutorial for those with little or no transmission imaging experience and as a source of ideas for SEM users looking to expand the imaging and diffraction capabilities of their equipment.

TEM specimens prepared using a Ga FIB are susceptible to artifacts, such as surface amorphization and ion-implanted layers, that can be problematic in advanced technology nodes, particularly for FinFETs. As this article shows, however, post-FIB cleaning via concentrated argon ion milling makes for a fast and effective specimen preparation process for FinFET devices controlled to a thickness of less than 20 nm. Although the results presented here are based on 14 nm node FinFETs, the method is also applicable to the 10 and 7 nm FinFET technologies currently in production.

Transmission electron microscopes have been improved in various ways over the past two decades, giving rise to new characterization techniques. Among the innovations discussed in this article are the introduction of field emission guns, the incorporation of CCD cameras and X-ray detectors, and the use of lens correction systems. Such improvements have had a significant impact on failure analysis through the emergence of new TEM techniques, including precession electron diffraction for grain and strain analysis, noise reduction processing for low dose EELS mapping of ultra-low-k materials, and EDX tomography for elemental 3D imaging of defects on a nanometer scale.

Ex-situ lift out (EXLO) techniques rely on van der Waals forces to transfer FIB milled specimens to various types of carriers using a glass probe micromanipulator. This article describes some of the latest EXLO techniques for site specific scanning transmission electron microscopy, including the use slotted half-grids and vacuum-assisted lift out for plan-view analysis.

Recent developments in automated image acquisition and metrology using transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) have significantly improved the speed, precision, and usability of these techniques for controlling advanced semiconductor device manufacturing processes. As device dimensions have continued to shrink, these techniques may be needed to replace scanning electron microscopy (SEM) for the smallest critical dimension (CD) measurements. This article describes the use of automated S/TEM in a high-throughput CD-metrology workflow to support process development and control and explains how automated sample-preparation, data-acquisition, and metrology tools increase both throughput and data quality.

Off-axis electron holography is a TEM-based imaging technique that reveals dopant anomalies and junction profiles in semiconductor devices. This article explains how the method works and how it is being used to visualize transistor source-drain regions, diffusion-related defects, and other features of interest in TEM samples. It also discusses related challenges and compares off-axis electron holography with other profiling techniques, particularly junction staining.

This article discusses the practice of FIB-based in situ lift-out, a sample preparation method that has proven particularly useful for failure analysis. It explains how samples are now being made for a wide range of TEM techniques, including holography, tomography, high-angle annular dark-field scanning, and electron energy-loss spectroscopy. In most cases, achieving optimal quality requires the use of alternate FIB milling angles, as in plan-view, sideways, and backside milling, all of which are discussed.

Shortcuts in failure analysis are sometimes to save time or money or because equipment or expertise is unavailable. This article presents simple but effective solutions in four areas, including deprocessing, FIB milling, microcleaving, and TEM sample preparation, that may help analysts work through or around such situations.

Energy-filtered transmission electron microscopy (EFTEM) is an imaging technique that uses inelastically scattered electrons and energy filters to produce high-quality images and elemental maps. This article reviews the measurement physics of EFTEM, compares and contrasts it with other imaging and chemical analysis techniques, and presents several application examples to demonstrate its use in semiconductor device failure analysis.