This chapter discusses the use of electron microscopy in metallographic analysis. It explains how electrons interact with metals and how these interactions can be harnessed to produce two- and three-dimensional images of metal surfaces and generate crystallographic and compositional data as well. It discusses the basic design and operating principles of scanning electron microscopes, transmission electron microscopes, and scanning transmission electron microscopes and how they are typically used. It describes the additional information contained in backscattered electrons and emitted x-rays and the methods used to access it, namely wavelength and energy dispersive spectroscopy and electron backscattering diffraction techniques. It also describes the role of focused ion beam milling in sample preparation and provides information on atom probes, atomic force microscopes, and laser scanning microscopes.

Several specialized instruments are available for the metallographer to use as tools to gather key information on the characteristics of the microstructure being analyzed. These include microscopes that use electrons as a source of illumination instead of light and x-ray diffraction equipment. This chapter describes how these instruments can be used to gather important information about a microstructure. The instruments covered include image analyzers, transmission electron microscopes, scanning electron microscopes, electron probe microanalyzers, scanning transmission electron microscopes, x-ray diffractometers, microhardness testers, and hot microhardness testers. A list of other instruments that are usually located in a research laboratory or specialized testing laboratory is also provided.

This article provides an overview of the most common micro-analytical technique in the failure analysis laboratory: energy dispersive X-ray spectroscopy (EDS). It discusses the general characteristics, advantages, and disadvantages of some of the X-ray detectors attached to the scanning electron microscope chamber including the lithium-drifted EDS detector, silicon drift detector (SDD), and wavelength dispersive X-ray detector. The article then provides information on qualitative and quantitative X-ray analysis programs followed by a discussion on EDS elemental mapping. The discussion includes a comparison of scanning transmission electron microscope-EDS elemental mapping and mapping with an SDD. A brief section is devoted to the discussion on the artifacts that occur during X-ray mapping.

There are several analytical methods available that can be used in-line on whole wafers as well as off-line on de-processed products that are returned from the field. These techniques are surface analytical techniques that can be used to characterize the bulk of the material. The main six methods used in semiconductor industry are: Auger spectroscopy, dynamic secondary ion mass spectroscopy, time of flight static secondary ion mass spectroscopy (ToF-SIMS), X-ray photoelectron spectroscopy, scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX), and transmission electron microscope-EDX. This review specifically addresses ToF-SIMS and describes some typical examples of the application of Auger and SEM-EDX.

This article presents methods that enable one to consistently, uniformly and quickly remove substrate silicon from units without imparting damage to the structure of interest. It provides examples of electron beam probing and backside nano-probing techniques. The electron beam probing techniques are E-beam Logic State Imaging, Electron-beam Signal Image Mapping, and E-beam Device Perturbation. Backside nano-probing techniques discussed include: Electron Beam Absorbed Current, Electron Beam Induced Resistance Change, four terminal resistance measurements, resistive gate defect identification, and circuit editing. The article also presents methods to prepare electron beam probing samples where some remaining silicon is required for the transistor functions and transmission electron microscope samples from units where the substrate silicon has been partially or completely removed.

The ultimate goal of the failure analysis process is to find physical evidence that can identify the root cause of the failure. Transmission electron microscopy (TEM) has emerged as a powerful tool to characterize subtle defects. This article discusses the sample preparation procedures based on focused ion beam milling used for TEM sample preparation. It describes the principles behind commonly used imaging modes in semiconductor failure analysis and how these operation modes can be utilized to selectively maximize signal from specific beam-specimen interactions to generate useful information about the defect. Various elemental analysis techniques, namely energy dispersive spectroscopy, electron energy loss spectroscopy, and energy-filtered TEM, are described using examples encountered in failure analysis. The origin of different image contrast mechanisms, their interpretation, and analytical techniques for composition analysis are discussed. The article also provides information on the use of off-axis electron holography technique in failure analysis.

This article covers common techniques for surface characterization, including the modern scanning electron microscopy and methods for the chemical characterization of surfaces by Auger electron spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry. The principles of surface analysis and some of the applications of the technique in polymer failure studies are also provided.

This chapter discusses the principles of scanning transmission electron microscopy (STEM) as implemented using conventional scanning electron microscopes (SEMs). It describes the pros and cons of low-energy imaging and diffraction, addresses basic hardware requirements, and provides information on imaging modes, detector positioning and alignment, and the effect of contrast reversal. It also discusses beam convergence and angular selectivity, the use of application-specific masks, and how to generate grain orientation maps for different material systems.

This chapter provides perspective on the physical dimensions associated with the microstructure of steel and the instruments that reveal grain size, morphology, phase distributions, crystal defects, and chemical composition, from which properties and behaviors derive. The chapter also reviews the definitions and classifications used to identify and differentiate commercial steels, including the AISI/SAE and UNS designation systems.

This chapter discusses the setup and use of a transmission electron detector in a typical scanning electron microscope (SEM). It describes the arrangement and function of the primary components in the detector, following the signal path from the sample to a micromirror array where it is directed by the user to either a CMOS sensor (to record diffraction patterns) or a photomultiplier tube (to observe real-space images). The chapter discusses some of the nuances of digital imaging and diffraction and includes examples in which transmission electron detectors are used to analyze gold films, carbon nanotubes, zeolite sheets, and monolayer graphene. It also describes emerging techniques, including four-dimensional STEM, thermal diffuse scattering, energy filtering, aberration correction, and atomic resolution imaging.

This chapter provides an overview of the tools and techniques used to examine failure specimens and the wealth of information that can be obtained from fracture surfaces, cracks, wear patterns, and other such features. It discusses the use of metallography, fractography, and optical and electron microscopy. It presents a number of images recorded using these methods and explains what they reveal about the mode of fracture and the state of the component prior to failure.