A goal in the characterization of supported metal catalysts is to achieve particle-by-particle analysis of the charge state strongly correlated with the catalytic activity. Here, we demonstrate the direct identification of the charge state of individual platinum nanoparticles (NPs) supported on titanium dioxide using ultrahigh sensitivity and precision electron holography. Sophisticated phase-shift analysis for the part of the NPs protruding into the vacuum visualized slight potential changes around individual platinum NPs. The analysis revealed the number (only one to six electrons) and sense (positive or negative) of the charge per platinum NP. The underlying mechanism of platinum charging is explained by the work function differences between platinum and titanium dioxide (depending on the orientation relationship and lattice distortion) and by first-principles calculations in terms of the charge transfer processes.

Noise reduction using the wavelet hidden Markov model (WHMM) was applied to electron holograms of a LaFeO₃/SrTiO₃ specimen, which was subjected to phase retrieval by the phase-shifting method. A systematic study revealed the optimal conditions regarding the electron dose and number of holograms used for phase retrieval, for which the effect of denoising was most pronounced. The denoised holograms revealed the magnitude of the phase shift at the LaFeO₃/SrTiO₃ interface, while the original, noisy holograms did not allow for accurate measurements. The observations demonstrate the usefulness of denoising using the WHMM.

Observing the surface structure and charge dynamics of catalysts during catalytic reactions is crucial for elucidating reaction mechanisms. However, nanoscale characterization of the catalyst structure and charge states in the presence of reactive gases presents experimental challenges. Here, the structures and charge states of a gold nanoparticle (NP) are directly visualized on ceria during redox cycles using electron holography, a method related to transmission electron microscopy. The introduction of oxidizing O ₂ gas to the microscope led to structural changes on the NP surface and decrease the intrinsic negative charge of the NP. Conversely, under reducing H ₂ gas, the surface structure and charge state of the NP remained almost unchanged compared to those in vacuum. Systematic analysis revealed that the injection and removal of O ₂ gas caused reversible changes in the charge state of the NP within the range of a few electrons. The effect of O ₂ gas on charging of the NP is confirmed by first‐principles calculations. These findings demonstrate the potential of electron holography in gas environments for advancing the understanding the reaction mechanisms on heterogeneous catalysts.

Hardware Trojans (HTs) are regarded as a security threat in the information society. HTs are unintentionally injected into LSI circuits by untrusted entities before the chip fabrication. HTs trigger malicious operations such as information leakage without designers noticing their operations. This paper proposes fine-grained power domain partitioning, which is a circuit design technique for detecting HT activities. This paper assumes a scenario where a fab injects HTs into the taped-out layout data and that circuit designers test the presence of HTs by using side-channel information (power consumption) of fabricated chips. Fine-grained power domain partitioning decomposes the power domain of target circuit into multiple power domains, enabling to effectively measure the small power consumption introduced by activities of tiny HTs. The measurement result using an HT-injected Advanced Encryption Standard (AES) circuit with fine-grained power domain partitioning shows that HTs can be detected.

The amount of light reflected from the light-irradiated device varies depending on the surface temperature at that location. In this paper, we show that, by using an incoherent light beam with a noninvasive wavelength, it is possible to measure the temperature change of the interconnect structure with a size of µm order Si semiconductor devices. As a method of measuring the temperature change, lock-in thermography has been reported. However, it is difficult to measure the temperature change of the fine structure. The spatial resolution of this method is about 10 µm. Here, by using a noninvasive incoherent light beam, the spatial resolution of µm order is achieved. We applied this method to a 4-µm-wide interconnect test element group (TEG) device with a passivation film to observe the temperature change of the interconnect structure.

In the advanced semiconductor materials industry, Japan has a competitive edge in the development of photosensitive materials (PM), which is essential for the growth of the industry. Herein, we clarify the technological trend and characteristics of both Front-end (FEOL/BEOL) and Back-end (BOL) processes by analyzing over 9,000 patents and representative conferences information. Subsequently, the trend similarity between the two processes are observed. Moreover, we obtain the disclosure characteristics categorized into defined categories based on the patent quality by visualizing the contents of registered patents and the examination status of each PM. Furthermore, we verify that the combination of both data is conducive to trend investigation.