Broad ion beam delayering is a versatile technique for whole-chip failure analysis. The large area of uniformity coupled with the ability to precisely stop at the layer of interest facilitates repeatable, rapid defect detection anywhere on the chip.

This column is part of a series of reports on the findings to date of the EDFAS Failure Analysis Roadmap Councils. The Failure Analysis Future Roadmap Council (FAFRC) is concerned with identifying the longer term needs of the FA community. This article discusses analysis challenges associated with the growing number of elements being incorporated into integrated circuit fabrication. It includes tables summarizing top challenges in front end and package analysis.

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.

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.

This article discusses the current state of large area integrated circuit deprocessing, the latest achievements in the development of automated deprocessing equipment, and the potential impact of advancements in gas-assisted etching, ion source alternatives, compact spectroscopy, and high-speed lasers.

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 a new technique for measuring temperatures in GaN HEMTs. The method is based on Raman spectroscopy and the use of cerium oxide particles that act like micro-Raman thermometers when scanned with a UV laser. As the article explains, phonon line shifts due to Raman scattering are used to estimate the temperature of GaN layers while surface temperatures are obtained through the cerium oxide particles. The results presented also verify that the particles, which are distributed over semiconductor and metal surfaces, do not modify the electric characteristics of the GaN devices.

Positron spectroscopy can identify defects deep within metals and semiconductors with a resolution better than a single atomic lattice site. This article discusses the basic principles and implementation of positron annihilation spectroscopy and a key development that makes it more a more useful tool for semiconductor applications.

This article discusses the development of resonance-enhanced AFM-IR spectroscopy and demonstrates its effectiveness on silicon test wafers with nanoscale skin particles and polyester contaminants.

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.

This article provides a practical overview of energy-dispersive spectroscopy (EDS) and its various uses in semiconductor device manufacturing and failure analysis. It explains how EDS techniques are typically implemented, compares and contrasts different methods, and discusses the factors that determine spatial and energy resolution, measurement depth, sensitivity, signal-to-noise ratio, and ease of use.

Virtually all semiconductor materials exhibit Raman scattering which results in a frequency shift in photon energy. In this article, the authors explain how they harness this mechanism to measure the temperature of submicron structures and thereby produce high-resolution temperature maps. They review the basic theory of Raman scattering and present application examples involving high-bandgap materials as well as silicon devices.

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.

Microcalorimeter-based energy-dispersive spectroscopy is a breakthrough in semiconductor material analysis. With an energy resolution of less than 10 eV, it allows the unambiguous identification of elements in the low-energy range (<3 kV) which, until now, required wavelength-dispersive techniques.

Scanning capacitance spectroscopy (SCS) is a new way to use a scanning capacitance microscope (SCM) to delineate pn junctions in silicon devices. SCS produces two-dimensional pn junction maps with features as small as 10 nm. It can also estimate the pn junction depletion width and hence doping levels near the junction. This article explains how SCS and SCMs allow a whole new regime of doping-related phenomena to be explored in Si devices and ICs.

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.

Recent advances in spectrometers now give sufficient sensitivity to measure the spectral content of the very weak light emission produced by failing semiconductor devices. This article examines light spectra from the most common defect classes in order to demonstrate the strengths and weakness of spectral analysis in the context of semiconductor failure investigations. The conclusion is that signature analysis may not provide a definitive root cause, but it can help confirm the root cause after further analysis is performed.

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.

Electronic device failure analysis usually starts with electrical testing, followed by visual inspection via optical microscopy, then examination in a scanning electron microscope. When imaging reveals the need to determine the composition of materials, defects, and suspected contaminants, the electron beam produced by the SEM can be used to obtain the necessary information. As the article explains, this is the basic concept behind the method known as energy dispersive X-ray spectroscopy (EDS or EDX) and the key to its widespread use. In addition, the article presents three examples showing how SEM/EDS measurements helped failure analysts identify human contaminants on a die sample, determine the source of a particle embedded in the film stack on a wafer, and conclude that lead spatter from a solder die-attach preform caused wire bond lift.