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.

This column discusses the potential benefits of developing a dedicated synchrotron-based tool suite for advanced, high-throughput characterization, deprocessing, and validation of ICs.

This article describes how physical attacks can be launched on different types of nonvolatile memory (NVM) cells using failure analysis tools. It explains how the bit information stored inside these devices is susceptible to read-out and fault injection attacks and defines vulnerability parameters to help quantify risks associated with different modalities of attack. It also presents an in-depth security analysis of emerging NVM technologies and discusses potential countermeasures.

This article describes a hardware metering fingerprint technique, called the memometer, that addresses supply chain integrity issues with field-programmable gate arrays (FPGAs). The memometer is a physically unclonable function (PUF) based on cross-coupled lookup tables that overcomes manufacturing memory power-on preset. The fingerprints are not only unique, but also reliable with average hamming distances close to the ideal values of 50% (interchip) and 0% (intrachip). Instead of having one fingerprint per device, the memometer makes provision for hundreds with the potential for more.

Engineers at IBM’s Watson Research Center are contending with one of the most fundamental limitations of imaging technology: the tradeoff between spatial resolution and field of view. In this article, they explain how they created tool interfaces, control and automation software, and image analysis and stitching algorithms, enabling photon emission and laser scanning microscopes to produce high-resolution mosaic images of advanced processor cores and other large-area ICs. They describe some of the challenges they faced and explain how their technology can be used to create images based on reflected light, induced voltage, photon emission, and laser stimulation signatures. In one of the latest demonstrations, the technology was used to land and focus a SIL more than 4000 times, acquiring some 16,000 images that were composed into stitched mosaics of several hundred images each.

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.

Interposers play an important role in 2.5D and 3D packages, routing power and communication signals between dies while maintaining electrical contact with I/O pins. This role and their relatively simple construction makes interposers a target for malicious attacks. In this article, the authors assess the vulnerabilities inherent in the fabrication of interposers and describe various types of optical attacks along with practical countermeasures.

Integrated circuits embedded in everyday devices face an increased risk of tampering and intrusion. In this article, the authors explain how reverse engineering techniques, including automated image analysis, can be employed to provide trust and assurance when dealing with commercial off-the-shelf chips.

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.

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.

A new product-like test chip developed by engineers at Carnegie Mellon University overcomes the current limitations in conventional test chip design. This article discusses the advantages of the new chip, called the CM-LCV, and presents experimental results showing how it achieves fault coverages comparable to or better than benchmarking designs.

This article proposes a design for a real-time Trojan detection system and explores possible solutions to the challenge of large-scale SEM image acquisition. One such solution, a deep-learning approach that generates synthetic micrographs from layout images, shows significant promise. Learning-based approaches are also used to both synthesize and classify cells. The classification outcome is matched with the design exchange format file entry to ensure the purity of the underlying IC.

This article describes a proposed novel metric to furnish chip designers with a prognostic tool for x-ray imaging in the pre-silicon stage. This metric is fashioned to provide designers with a concrete measure of how visible the fine-pitched features of their designs are under x-ray inspection. It utilizes a combination of x-ray image data collection, analysis, and simulations to evaluate different design elements.

Further development of SEM-based feature extraction tools for design validation and failure analysis is contingent on reliable sample preparation methods. This article describes how a delayering framework for 130 nm technology was adapted and used on a 45 nm SPI module consisting of 11 metal layers, 10 via layers, two layers of polysilicon, and an active silicon layer. It explains how different polishing and etching methods are used to expose each layer with sufficient contrast for SEM imaging and subsequent feature extraction. By combining polygon sets representing each layer, the full design of the device was reconstructed as shown in one of the images.

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.

This article presents and evaluates a calibration method that significantly improves the spectral information that can be extracted from photon emission signals obtained from semiconductor devices. Step-by-step instructions are given for calibrating photon emission microscopes for specific measurements such as device parameters and material band gap. The article also discusses the types of errors that can occur during calibration. Although the procedure presented is used on InGaAs sensors, it applies to all common photon emission detectors.

Circuit boards are vulnerable to a wide range of ill-intentioned modifications done to gain access to information or malevolently influence control. This article describes the various ways attacks on circuit board can occur and presents examples showing how such attacks might look. It also provides general guidelines for protecting circuit-board design integrity.

The Internet of Things concept is the “next big thing,” but what are the obstacles to achieving its potential? This article describes some key challenges with this evolving technology, including device failure, sensitivity, scalability, middleware, and user interaction.

The semiconductor industry continues to scale microelectronics in accordance with Moore’s Law, as the minimum feature size on integrated circuits has decreased from 800 nm in 1993 to 90 nm in 2003 to 22 nm today. In addition, manufacturing advances include 3-D packaging, with multiple dice stacked in various configurations, and 3-D integrated circuits that use through-silicon vias or through-oxide vias to connect the various dice layers. The Intelligence Advanced Research Projects Activity (IARPA) Circuit Analysis Tools (CAT) program is developing tools and techniques to ensure that the U.S. government has capabilities for circuit analysis at future technology nodes, specifically at 22 nm and beyond, and for chips assembled using advanced packaging techniques. This column describes the CAT program activities and goals.

The second phase of the IARPA Circuit Analysis Tools (CAT) program, which ended in June 2015, focused on the development of prototype tools to demonstrate scalability to the 10 nm node. Our guest columnist, IARPA Program Manager, Carl E. McCants, provides a summary of what the participating teams accomplished.