Integrated circuits are subjected to various forms of friction during fabrication and packaging, creating potential problems due to the buildup of charge. This article looks at the distinct characteristics of triboelectric charging damage on silicon-on-insulator devices at the wafer and package level. Telltale signs of this type of damage include spatial dependency, distinct TIVA-signal patterns, and bimodal static current distributions with significant changes after burn-in.

This article explains how oxide traps and mobile ions can lead to timing and function failures in ICs and provides insights and advice on how to identify and deal with potential problems.

Scanning electron microscopes can be used to analyze almost anything that conducts electricity and is prone to failure, including relays, coils, inductors, capacitors, resistors, transistors, diodes, IGBTS, MOSFETS, and hybrid circuits. As the author of the article explains, SEMs are one of the most versatile tools for failure analysis if used to the full extent of their capabilities. Their operating modes include emissive imaging, backscattering, voltage contrast, EBIC or specimen current, and conductivity resistive mapping. The author describes each operating mode and presents examples of the various ways they can be used.

Scanning nonlinear dielectric microscopy (SNDM) is a scanning probe technique that measures changes in oscillation frequency between the probe tip and a voltage-biased sample. As the probe moves across the surface of a semiconductor device, the oscillation frequency changes in response to variations in dielectric properties, charge and carrier density, dopant concentration, interface states, or any number of other variables that affect local capacitance. Over the past few years, researchers at Tohoku University have made several improvements in dielectric microscopy, the latest of which is a digital version called time-resolved SNDM (tr-SNDM). Here they describe their new technique and present an application in which it is used to acquire CV, d C /d V-V , and DLTS data from SiO 2 /SiC interface samples.

Secondary ion mass spectrometry (SIMS) works by bombarding the surface of a solid sample with ions, freeing charged atomic and molecular species which are then collected and analyzed. This article explains that SIMS has the ability to detect all elements in the periodic table in addition to inherent depth profiling capabilities, making it an indispensable tool for the characterization and analysis of semiconductor components and materials. It also presents several application examples.

This article provides a qualitative overview of several new defect localization techniques, including charge-induced voltage alteration (CIVA), light-induced voltage alteration (LIVA), thermally-induced voltage alteration (TIVA), and Seebeck effect imaging (SEI). It explains how each method works in terms of the physics of signal generation and the types of images they produce. It also includes a summary highlighting the similarities and differences of each technique.

A string of failures discovered during final testing after assembly led analysts on a long search for the cause, which turned out to be an unusual form of electrostatic discharge (ESD). Most ESD impacts on ICs occur by way of the pins. Nearly all ESD models, including the widely used human body model, charged-device model, and machine model, are based on this assumption. However, as this case study proves, passivated wafers and unpackaged dies are also susceptible to ESD damage. The authors explain that although this type of failure is difficult to diagnose, they were able to pinpoint the cause using lock-in microthermography and rule out mechanical-, FIB-, and laser-induced failures, which are similar in appearance.

This article provides an introduction to scanning ion microscopy, explaining how it overcomes one of the biggest limitations of SEMs, namely the tradeoff between spatial resolution and depth of field, while also providing significantly more surface detail, a wide range of novel and familiar contrast mechanisms, and the potential for new microanalytical techniques that combine nanometer spatial resolution and single monolayer sensitivity. In addition to describing the capabilities of scanning ion microscopes, the article also addresses the issue of sample charging and the potential for physical damage that can result from ion beam irradiation.

One of the co-chairs of the Case Histories sessions at ISTFA 2012 provides a summary of three papers that demonstrate a solid understanding of the semiconductor FA process. The first paper describes the investigation of fractures in PCB traces, the second paper presents a method for analyzing defects due to implanter charging effects, and the third paper explains how analysts determined the cause of automatic test pattern generation failures concentrated in certain areas of the wafer.

This article presents a new technique for monitoring the health of lithium-ion cells. Whereas traditional methods use current, voltage, and temperature data to infer the overall health of the cell, the new method uses ultrasonic measurements to assess structural changes such as swelling, expansion, ruffling, and delamination. The article explains how and why these changes occur, how they are measured, and how they correlate with loss of battery capacity, safety, and failure. It also discusses the effect of charge and discharge cycles and the factors that contribute to gas generation.

This article reviews recent work aimed at characterizing soft-error effects in SRAM circuits fabricated with bulk silicon FinFETs. Accelerated tests were conducted on 6T planar and FinFET-based SRAM cells by exposing them to high-energy neutrons and alpha particles. Based on test results and simulations, the authors show that soft-error rates are much lower in FinFET devices because the geometry of the fins limits charge collection.

The causes of failure in flip-chip packaged devices are often found at the interface between the die and package. Exposing the site of interest usually entails some form of mechanical cross-sectioning with the sample embedded in an epoxy puck. This article brings attention to some of the drawbacks with the current approach and presents a solution in the form of a redesigned puck. As test results show, the new puck significantly reduces polishing time, and when cast with a conductive epoxy, minimizes charging artifacts and image distortion during SEM analysis. It also facilitates easy sample removal for subsequent analysis.

Using the example of smart card radio frequency identification (RFID) devices, this article examines electrostatic discharge risk scenarios encountered during assembly and in the field, and outlines basic countermeasures.

Optical second-harmonic generation (SHG) is a noninvasive technique that provides information about interface properties and crystal defects. This article demonstrates the use of SGH in the study of high-k dielectrics, silicon-on-insulator structures, compound semiconductors, and through-silicon vias.

Scanning electron microscopes (SEMs) are the dominant tool for electronic device testing, failure analysis, and characterization. This status was not apparent, however, when the first commercial SEM, the Cambridge Stereoscan, appeared in 1963. A market survey by the manufacturer at that time predicted total sales of six to ten units worldwide. For the last four decades, SEMs have sold at an average rate of one unit every 24 hours, with two out of every three instruments destined for the semiconductor industry.

A guest columnist shares some of the lessons learned in the course of his career. The wisdom contained in these lessons can be summed up as follows: look at the problem from different perspectives, believe the data, and don’t give up too soon.

Automotive electronics are exposed to mechanical shock and vibration, thermal cycling, chemical attack, current and voltage spikes, electromagnetic interference, and other hazards. Early life failures, which are not uncommon, can be difficult to diagnose due to the many contributing factors. This article provides an overview of automotive electronic failures and presents guidelines for determining the root cause.

This article discusses the basic principles of dark current spectroscopy (DCS), a measurement technique that can detect and identify low levels of metal contaminants in CMOS image sensors. An example is given in which DCS is used to determine the concentration of tungsten and gold contaminants in an image sensor and estimate the dark current generated by a single atom of each metal.

Techniques used by failure analysts to provide proper stimuli to diagnose failures in mixed-signal ICs differ from routine digital IC tester stimuli. Mixed-signal parts not only require vector stimulus (i.e., set timing and frequency base), but also analog output sense signals, which are classified by differences in magnitude, frequency, and current. This article explains how a mixed-signal ASIC was analyzed using various signal stimuli.

This article discusses the primary differences between electrostatic discharge (ESD) and electrical overstress (EOS) and the circumstances under which they occur. It also explains how to differentiate ESD from EOS during failure analysis and how to avoid common misunderstandings and mistakes.