Magnetic field imaging is proving to be a valuable tool for semiconductor failure analysts and test engineers. One of its main advantages is that it does not require sample preparation or deprocessing because magnetic fields pass through most materials used in ICs and device packages. This article discusses the theory and practical limitations of magnetic field imaging and demonstrates its use in mapping current density and determining the location and depth of current-carrying conductors.

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.

Voltage contrast followed by electron beam induced current imaging is an effective approach for isolating IC failures. This article briefly reviews the physics of signal generation for both techniques and presents several examples illustrating how this powerful combination contributes to advanced defect localization.

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.

A review of the 2001 edition of the International Technology Roadmap for Semiconductors indicates major obstacles ahead. Of the three basic failure analysis steps—inspection, deprocessing, and fault isolation—the latter is the most at risk, especially physical fault isolation.

This article discusses the basic procedures involved in atom probe tomography (APT) and demonstrates its use on complex material stacks. Although still a relatively new technique, APT has moved to the forefront of semiconductor failure analysis because it can provide 3D chemical composition of a wide range of materials on a near-atomic scale.

Semiconductor trends, as embodied in the International Technology Roadmap for Semiconductors (ITRS), provide a guide for the challenges facing the failure analysis community. This process is a risk assessment of key features forecast for the impact of future technologies on failure analysis. The technical challenges fall primarily into two categories: failure site isolation and physical analysis. The failure site isolation challenges are largely driven by the device complexity and reduced accessibility of circuit nets. Additional challenges arise due to the increase in device operating speed and pin count. The challenges in physical analysis are driven primarily by smaller device feature sizes and by the host of new materials being introduced. In addition to the technical challenges, infrastructure changes are also likely to occur. The industry paths for addressing these challenges are discussed.

In many companies, failure analysis (FA) has evolved to mean much more than analyzing a part from yesteryear and filing a report simply to satisfy a requirement. Failure analysis engineers frequently interface with design, test, and product engineering and are an integral part of yield improvement. This article addresses several common misperceptions about the failure analysis process.

This article discusses the emergence of nanoelectronics and the effect it may have on semiconductor testing and failure analysis. It describes the different types of quantum effect and molecular electronic devices that have been produced, explaining how they are made, how they work, and the changes that may be required to manufacture and test these devices at scale.

Magnetic current imaging provides electrical fault isolation for shorts, leakage currents, resistive opens, and complete opens. In addition, it can be performed nondestructively from either side a die, wafer, packaged IC, or PCB. This article reviews the basic theory and attributes of MCI, describes the types of sensors used, and discusses general measurement procedures. It also presents application examples demonstrating recent advancements and improvements in MCI.

This article discusses the use of scanning-beam techniques such as EBIC, IBIC, and OBIC to optimize the design of edge-termination structures in vertical GaN and AlGaN power diodes.

Microelectronics failure analysis is based on several approaches to study and understand the origin of failure. In addition to “classic” elemental methods (SIMS, ESCA, etc.), there are a number of less-common techniques that can be valuable but require significant equipment investment, specialized operators, and administrative infrastructure to make them available to analysts, if needed. Ion beam analysis methods (RBS, PIXE, NRA), found at the Bordeaux Nuclear Research Center (France), are examples of these specialized tool sets. The capabilities and improved sensitivities of this site for device examination are demonstrated by several examples.

This article discusses the basic principles of terahertz time-domain spectroscopy (THz-TDS) and the function and limitations of key components in a THz-TDS system. It also provides examples of some of the ways THz-TD imaging is used alone and in combination with other analytical techniques.

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.

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.

Recent work with a commercial instrument based on a SQUID sensor shows that magnetic field imaging can be very effective in isolating defect shorts in packages and dies. This technique is especially beneficial when the defect is buried under layers of metal, Si, or encapsulation materials. Many of these defects can be imaged for coarse localization without any deprocessing of the sample. SQUID sensors can produce weak current images even in the presence of background current five orders of magnitude stronger. This high sensitivity also enables effective imaging with much lower currents than thermal techniques.

Magnetic current imaging is a proven fault-isolation technique. Its unsurpassed sensitivity and resolution coupled with the fact that magnetic fields are unaffected by packaging and die materials make it a valuable FA tool for a wide variety of ICs and devices. This article reviews the basic measurement physics of magnetic current imaging, describes the general implementation, and presents several practical examples of its use.

This article explains how the failure of a high-voltage capacitor led to the discovery of an unusual defect. Testing showed that the capacitor shorted due to silver migration, which investigators believe was facilitated by voids in the dielectric that had been present from the time of manufacture. Through some combination of time, electric potential, trapped humidity, and elevated operating temperature, plate material migrated into the voids, creating a short path that led to the failure. Using acoustic images as a guide, the failed capacitor was cross-sectioned, allowing investigators to examine the voids more closely and thereby confirm their theory.

Engineers at the Fraunhofer Institute for Microstructure of Materials and Systems built and are testing a scanning acoustic microscope (SAM) that operates at frequencies of up to 2 GHz. Here they describe the design of their GHz-SAM and present examples showing how it is used to detect stress induced voids, inspect wire bond interfaces, and examine through-silicon vias (TSVs) in the time-resolved mode.

Deprocessing of ICs is often the final step for defect validation in FA cases with limited fault-isolation information. This article presents a workflow for deprocessing ICs from the backside using automated thinning and large-area plasma FIB delayering. Advantages to this approach include a reduction in manual planarization and depackaging and a higher degree of precision and repeatability.