STEM-EBIC imaging, a nano-characterization technique, has been used in the study of electrically active defects, minority carrier diffusion length, surface recombination velocity, and inhomogeneities in Si pn junctions. In this article, the authors explain how they developed and built a STEM-EBIC system, which they then used to determine the junction location of an InGaN quantum well LED. They also developed a novel FIB-based sample preparation method and a custom sample holder, facilitating the simultaneous collection of Z-contrast, EBIC, and energy dispersive spectroscopy images. The relative position of the pn junction with respect to the quantum well was found to be 19 ± 3 nm from the center of well.

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 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.

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.

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.

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.

Localizing defects in one-of-a-kind failures can take days, weeks, or even months, after which a detailed physical analysis is conducted to determine the root cause. TEM and STEM play complimentary roles in this process; TEM because of its superior spatial resolution and STEM because it produces images that are easier to interpret and is less susceptible to chromatic aberrations that can occur in thicker samples. In the past, the use of STEM in FA has been limited due to the time required to switch between imaging modes, but with the emergence of TEM/STEM microscopes with computer controlled lenses, the use of STEM is increasing. This article provides an overview of STEM techniques and present examples showing how it is used to characterize subtle and complex defects in ICs.

Scanning TEM electron beam-induced current (STEM EBIC) imaging is a promising technique for providing high-resolution electronic and thermal contrast as a complement to TEM’s physical contrast. This article presents recent progress in using the focused ion beam (FIB) to prepare thin, electrically contacted cross-section samples for STEM EBIC imaging and in situ biasing. Techniques involving both standard Ga+ FIB and Xe+ plasma FIB (PFIB) are described.

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.

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.

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.

This column describes a unique arrangement between two IC manufacturers that built and share a state-of-the-art failure analysis laboratory. The lab is dedicated to helping the two companies characterize their new technologies, debug new designs, measure IC performance, find defects responsible for yield loss, and improve product reliability. In addition to discussing the technical capabilities of the lab, our guest columnist also explains how the lab is funded and managed.

This article describes how focused ion beam (FIB) technology is being used in combination with various other analytical tools for failure and yield analysis of MEMS devices. It provides examples showing how FIB is used with TEM analysis, AFM analysis, scanning acoustic microscopy, and scanning laser microscopy.

X-ray tomography has been rapidly gaining acceptance in the semiconductor industry since the first demonstration of its use on IC interconnect in 1999. As failure analysts are discovering, X-ray imaging is more powerful than visible light microscopy and can be used to analyze larger samples than those that fit in an electron microscope. This article provides an introduction to the physics, signal processing, and algorithms involved in X-ray imaging and tomography and the factors that affect resolution.

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 describes two innovative methods that can significantly improve the resolution of SEM imaging: scanning transmission electron microscopy in a scanning electron microscope (STEM-in-SEM) and forward-scattered electron imaging (FSEI). Both methods can be implemented in any SEM using special sample holders. No other modifications are required. Test results presented in the article show that 1 to 2 nm resolution is possible in thin sections, uncoated polysilicon gates, and photoresist.

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.

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.

The third extended European Failure Analysis Network (EUFANET) workshop, “Smart FA for New Materials in Electronic Devices,” was held in Dresden, Germany, September 17-18, 2012. This article provides a summary of the event with highlights from presentations on flexible organic electronics, crystal defects in SiC, nanoprobing, and the capabilities of nano X-ray tomography.

This article explains why it has become necessary for equipment builders to analyze passive component failures and how the findings should be reported to manufacturers. It describes the general approach and steps involved in analyzing passive component failures and the methods and equipment used. It also explains how an actual failure involving a microwave switch was resolved.