Focused Ion Beam sample preparation for electron microscopy often requires large volumes of material to be removed. Prior efforts to increase the rate of bulk material removal were mainly focused on increasing the primary ion beam current. Enhanced sputtering yield at glancing ion beam incidence is known, but has not found widespread use in practical applications. In this study, etching at glancing ion beam incidence was explored for its advantages in increasing the rate of bulk material removal. Anomalous enhancement of material removal was observed with single raster etching in along-the-slope direction with toward-FIB raster propagation at glancing ion beam incidence. Material removal was inhibited with raster propagation away from FIB. The effects of glancing angle and ion dose on depth of cut and volume of removed material were also recorded. We demonstrated that the combination of single-raster etching in along-the-slope direction by raster propagating toward-FIB at glancing incidence and a “staircase” type of etching strategy holds promise for reducing the process time for bulk material removal in FIB sample preparation applications.

Widespread adoption and significant developments in Focused Ion Beam technology has made FIB/SEM instrumentation a commonplace sample preparation tool. Fundamental limitations inherent to Ga ion species complicate usage of Ga+ FIB instruments for the modification of semiconductor devices on advanced technology nodes. Said limitations are fueling interest in exploring alternative primary species and ion beam technologies for circuit edit applications. Exploratory tests of etching typical semiconductor materials with Xe ion beams generated from two plasma ion sources confirmed advantages of Xe+ as a potential ion species for gas-assisted etching of semiconductor materials, but also revealed potential complications including, swelling of metal and Xe+ retention within the material arising from excessive Xe ion beam current density.

X-ray tomography is a promising technique that can provide micron level, internal structure, and three dimensional (3D) information of an integrated circuit (IC) component without the need for serial sectioning or decapsulation. This is especially useful for counterfeit IC detection as demonstrated by recent work. Although the components remain physically intact during tomography, the effect of radiation on the electrical functionality is not yet fully investigated. In this paper we analyze the impact of X-ray tomography on the reliability of ICs with different fabrication technologies. We perform a 3D imaging using an advanced X-ray machine on Intel flash memories, Macronix flash memories, Xilinx Spartan 3 and Spartan 6 FPGAs. Electrical functionalities are then tested in a systematic procedure after each round of tomography to estimate the impact of X-ray on Flash erase time, read margin, and program operation, and the frequencies of ring oscillators in the FPGAs. A major finding is that erase times for flash memories of older technology are significantly degraded when exposed to tomography, eventually resulting in failure. However, the flash and Xilinx FPGAs of newer technologies seem less sensitive to tomography, as only minor degradations are observed. Further, we did not identify permanent failures for any chips in the time needed to perform tomography for counterfeit detection (approximately 2 hours).

Reverse engineering of electronics systems is performed for various reasons ranging from honest ones such as failure analysis, fault isolation, trustworthiness verification, obsolescence management, etc. to dishonest ones such as cloning, counterfeiting, identification of vulnerabilities, development of attacks, etc. Regardless of the goal, it is imperative that the research community understands the requirements, complexities, and limitations of reverse engineering. Until recently, the reverse engineering was considered as destructive, time consuming, and prohibitively expensive, thereby restricting its application to a few remote cases. However, the advents of advanced characterization and imaging tools and software have counteracted this point of view. In this paper, we show how X-ray micro-tomography imaging can be combined with advanced 3D image processing and analysis to facilitate the automation of reverse engineering, and thereby lowering the associated time and cost. In this paper, we demonstrate our proposed process on two different printed circuit boards (PCBs). The first PCB is a four-layer custom designed board while the latter is a more complex commercial system. Lessons learned from this effort can be used to both develop advanced countermeasures and establish a more efficient workflow for instances where reverse engineering is deemed necessary. Keywords: Printed circuit boards, non-destructive imaging, X-ray tomography, reverse engineering.

Possible methods for counterfeit electronic part detection can be classified into two main categories: physical inspection and electrical testing. The physical inspection techniques can potentially be extended to different integrated circuit (IC) types; however, there are some challenges. The major contribution of this paper is to tackle these issues by introducing and optimizing two novel three and four dimensional imaging techniques that can provide us with the necessary information on interior and exterior geometry along with the material composition for the parts under test: four-dimensional scanning electron microscopy and dual energy 3D x-ray microscopy. In this study, advanced image processing and image analysis tools are utilized to establish a more consistent and accurate image perception. Inconsistencies within the samples and their defects are also used as an alternative to having a golden IC. However, the final decision has further been validated using results from five known authentic samples.