Single contact optical beam induced currents (SCOBIC) is a variation on the OBIC failure analysis technique that requires only one point of contact with the junction being examined. This article discusses the basic principles of this new method and how it compares with OBIC in terms of measurement performance. It also presents examples showing how SCOBIC can be used to analyze CMOS devices from the front and back side without need for complex FIB and microprobing procedures.

This article summarizes major discussion points from four User’s Group meetings held at the ISTFA 2009 conference. The topics addressed are "Optical Techniques: Growth and Limitations," "Resolution of Nanoprobing for 45 nm and Beyond: New Challenges," "FIB," and "Fast ASIC Fault Isolation: Efficiency and Accurate Resolution of Software-Based Fault Isolation."

The best spatial resolution that can be achieved with far-field optical fault localization techniques is around 20 times larger than the critical defect size at the 45 nm technology node. There is also a limit on the laser power that can be safely used on 45 nm devices, which further compromises fault localization precision. In this article, the authors explain how they overcome these limitations using pulsed laser-induced imaging techniques and a refractive solid immersion lens. Two case studies show how the combination of pulsed-laser scanning optical microscopy and a solid immersion lens improves localization precision and detection sensitivity.

The power of scanning optical microscopes (SOMs) lies in their ability to direct a small spot of light into an IC, producing photocarriers and heat in a localized area of the circuit. Photonic and thermal energy affect the I-V characteristics of the circuit in different ways, depending on the presence of defects and local material properties. This article explains how light beams interact with semiconductors and metals and how they influence the I-V characteristic of circuits and devices. It describes the basic physics of SOM measurements, provides examples of static and dynamic SOM techniques, and discusses emerging applications.

This column provides a ten-year retrospective on laser-based fault isolation techniques and the important role of laser signal injection microscopes.

Advancements in photodetector technology are revitalizing time-resolved emission (TRE) techniques in semiconductor failure analysis. In this article, the authors explain how superconducting single-photon detectors improve the capabilities of TRE measurements as demonstrated on 14 nm FinFET technology and an inverter chain with power supply voltages down to 0.4 V.

This column reviews a survey of the top ISTFA contributors from 1999 to 2008 and the topics addressed in their papers.

This article describes the basic measurement physics of scanning nitrogen vacancy (NV) microscopy and the various ways it can be used in semiconductor device failure analysis. Scanning NV microscopy can measure topography as well as magnetic fields, local current density, ac noise, and local temperature variations.

The 1997 National Technology Roadmap for Semiconductors (NTRS) and the 1999 International Technology Roadmap for Semiconductors (ITRS) include chapters outlining metrology needs for the silicon semiconductor industry during the next five years and beyond1. The grand challenges include affordable scaling, new materials and structures, and yield and reliability. Although additional requirements within these categories are detailed, it is often difficult for the analytical specialist or metrology equipment vendor to translate these grand challenges into detailed and meaningful roadmaps for success in analytical applications or instrument development. The path-to-impact of a single metrology activity is not always clear.

One of the pioneering developers of induced voltage alteration (IVA) measurement techniques assesses the current state of the technology, the impact of major advancements, and the potential for further improvements. The assessment pays particular attention to biasing approaches, phase-locked loop detection techniques, the effect of solid immersion lenses on spatial resolution, and the emergence of production-type sample preparation methods.

This article discusses the basic principles of SEM-based cathodoluminescence (CL) spectroscopy and demonstrates its usefulness in process development, statistical process control, and failure analysis. The technologies where the benefits of CL spectroscopy are most evident are compound semiconductor optoelectronics and high electron mobility transistors as reflected in the application examples.

The inverted orientation of a flip-chip packaged die makes it vulnerable to optical attacks from the backside. This article discusses the nature of that vulnerability, assesses the threats posed by optical inspection tools and techniques, and provides insights on effective countermeasures.

This article presents a comprehensive study of physical inspection and attack methods, describing the approaches typically used by counterfeiters and adversaries as well as the risks and threats created. It also explains how physical inspection methods can serve as trust verification tools and provides practical guidelines for making hardware more secure.

Chip-level 3D integration, where chips are thinned, stacked, and vertically interconnected using TSVs and microbumps, brings as many challenges as it does improvements, particularly in the area of failure analysis. This article assesses the capabilities of various FA techniques in light of the challenges posed by 3D integration and identifies current shortcomings and future needs.

Metrology targets are an essential tool for evaluating the performance of imaging systems and maintaining their accuracy over time. Ideally, the pattern on the target is simple enough that the expected image is intuitive or, at least, easily simulated. Although many such targets exist for frontside imaging, until recently, few if any could be found for backside applications. In this article, the first of a two-part series, the authors explain how they addressed this gap by converting a readily available frontside target for backside use. The conversion process is described step by step in enough detail that it can be replicated in order to convert other frontside targets. Due to the success of the converted target, an unmounted, backside-specific version has subsequently been developed, the availability of which not only eliminates one of the more difficult steps in the original conversion process, but also provides additional benefits. Using one of these newer targets, the authors evaluated a backside imaging system consisting of a laser scanning microscope (LSM) and a solid immersion lens (SIL). The results are presented here along with the criteria used for the evaluation. Other applications of the new metrology target as well as its limitations are discussed in the May 2015 issue of EDFA .

This article describes a novel method for improving image resolution achieved using time-resolved photon emission techniques. Instead of directly generating images from photon counting, all detected photons are displayed as a point cloud in 3D space and a new higher-resolution image is generated based on probability density functions associated with photon distributions. Unsupervised learning algorithms identify photon distribution patterns as well as fainter emission sources.

The transition to “flip-chip” packaging forced a renaissance in failure analysis methods, usually referred to as backside failure analysis. This article describes one such technique based on active laser probing. The technique uses the optical properties of the silicon substrate to produce a high-sensitivity, high-resolution thermal map of the device active area. This map can locate shorting defects and be used as a thermal management tool.

Researchers at Boston University have made significant improvements in the resolution that can be achieved with backside imaging techniques. In this article, they explain how they optimize lateral and longitudinal resolution of IR-based methods using aplanatic solid immersion lenses in combination with adaptive optics that correct for aberrations, interferometry to improve signal-to-noise ratios, vortex beams that overcome diffraction limitations, and image reconstruction techniques based on prior knowledge about the objects under investigation.

This article discusses the types of defects that occur in vertical cavity surface-emitting lasers (VCSELs) and the tools typically used to detect them and identify the cause. It describes the basic design and operation of VCSELs and explains that most failures are due to dislocations in the crystal structure of the materials from which the devices are made. Of the various methods used to analyze such defects, electroluminescence (EL) is by far the most powerful as demonstrated in several EL images included in the article. The article also discusses the use of EBIC analysis, FIB cross-sectioning, and thermally induced voltage alteration (TIVA).

Technologies relatively new to failure analysis, like time-correlated photon counting, electro-optical probing, antireflective (AR) coating, Schlieren microscopy, and superconducting quantum interference (SQUID) devices are being leveraged to create faster, more powerful tools to meet increasingly difficult challenges in failure analysis. This article reviews recent advances and research in fault isolation and circuit repair.