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A non-destructive method for detecting sub-micrometer-sized micropipes on an entire wafer surface is investigated. Since it is difficult to detect sub-micrometer-sized micropipes due to their small core size, a non-destructively and accurately detecting method is required. To solve the issue, we focus on a characteristic depression generated around micropipes, namely, line-shaped depressions. In this paper, the location of line-shaped depressions is identified by using optical inspection, and the line-shaped depressions are distinguished whether micropipes exhibit line-shaped depression or not by using mirror electron microscope observation as high-resolution inspection. The accuracy of the distinction results is confirmed by scanning electron microscope observation, and electrical characteristics of the P–N diode are fabricated using the inspected wafer. Furthermore, the sub-micrometer-sized micropipes are observed at the sites of leakage current identified by emission microscopy. Additionally, device simulation of the blocking-voltage characteristics of P–N diodes suggests that the increase in leakage current depends on the electric field at the sub-micrometer-sized micropipes, regardless of their core size. [ABSTRACT FROM AUTHOR]

Elucidation of microstructures responsible for hydrogen embrittlement is hoped for research and development of high-strength low-alloy steel. For this purpose, a novel in situ scanning electron microscopy method of hydrogen embrittlement was developed by using a near atmospheric-pressure hydrogen microplasma jet excited by pulsed glow discharge. By the developed method, propagations of hydrogen embrittlement cracks in typical martensitic steel, Japanese Industrial Standards SCM435 steel, were successfully observed at frame rates at least up to 10.2 Hz with the same image quality as in high vacuum. The hydrogen microplasma jet neither elevated the specimen temperature nor damaged the specimen surface. Strain evolution prior to the crack propagations was also successfully observed in conjunction with the digital image correlation technique. It was found that a small electron scattering cross section of the hydrogen molecule, a large density of hydrogen ions in the near atmospheric-pressure microplasma jet, and stabilization of the glow discharge by the electron beam of the scanning electron microscope play a crucial role in the realization of the in situ observations. [ABSTRACT FROM AUTHOR]

A crystal structure analysis of stacking faults (SFs) in a β-Ga2O3 (001) layer grown by halide vapor phase epitaxy (HVPE) was performed using scanning transmission electron microscopy. Etch pits were formed on the surface using alkaline molten salt etching and were used as a fiduciary mark during the analysis. The results revealed three types of defects. These defects were generated in the HVPE-grown layer (propagation from the defects of the β-Ga2O3 substrate grown using the edge-defined film-fed growth method played no role in the generation of these defects). The first type of defect involved SFs on the (−310) plane and resulted from the vacancy of gallium (Ga) atom sites of the GaO4 tetrahedral unit and the GaO6 octahedral unit. The second type involved SFs on the (1−11) plane and resulted from displacement of the GaO6 octahedral unit. The third type was presumed as a ribbon-folded defect with repeated SFs on the (111) and (7−27) planes or the (1−11) and (727) planes. [ABSTRACT FROM AUTHOR]

This study investigates the flow structures behind an atmospheric entry capsule at Mach number 0.4 through an improved detached eddy simulation and a modal analysis. The simulated flowfields reveal relatively low-frequency peaks of St ≈ 0.016 and St = 0.17–0.2 in the aerodynamic coefficient variation, where St is the nondimensional frequency. Then, the dominant fluid structures that cause the frequency peaks are identified through dynamic mode decomposition and the compressive-sensing-based mode selection method. Many of the dominant fluid phenomena have a frequency of St ≈ 0.2. In this frequency range, the fluid phenomena are mainly characterized with a large-scale vortex shedding separated from the capsule's shoulder part and with a helical fluid structure in the wake. Moreover, the variation in the lift coefficient of the capsule is mainly attributed to the large-scale vortex shedding phenomenon. Furthermore, a fluid phenomenon at a frequency of St = O(0.01) is found, which describes the pulsation, or periodic growth or shrinkage, of the recirculation bubble, accompanied by pressure fluctuation behind the capsule that exerts a large drag fluctuation of the capsule. Additionally, this phenomenon seems related to the dynamic instability phenomena of the capsule, as indicated by its time scale, which is close to that of the capsule's attitude motion. [ABSTRACT FROM AUTHOR]

Examines the radio-frequency glow discharges of several kinds of gases to measure the ion sheath thickness at the cathode electrode. Role of the secondary electron emission from the electrode surface in the discharges; Electrical characterization of the relative frequency plasma processing system; Pressure dependence of the sheath thickness in the argon discharge.

Deals with a study which examined the optical emission profile between anode and cathode electrodes for monitoring planar radio frequency discharges of hydrogen, nitrogen and argon gasses. Information on radio-frequency excited glow discharges; Methodology of the study; Results and discussion.

Presents a study that examined hard carbon films produced by rf glow discharge plasma decomposition of hydrocarbon gases diluted with hydrogen gas at relatively low temperature and pressure. Measurement of the optical emission spectra during the deposition of the carbon films; Correlation between the carbon film's properties and the condition of the plasma; Existence of diamond grains in the amorphous phase.

The main purpose of this study is to grow an organic thin film consisting of aromatic molecules with enhanced π-conjugations. For this purpose, an anthracene derivative, 9,10-bis (methylthio) anthracene, was deposited on a CaF2/Si(111) substrate using a hot-wall epitaxy technique. The crystal structure of this anthracene derivative consists of molecular stacks with a face-to-face configuration due to the sulfur-sulfur interactions between neighboring molecules, which enhances π-electron conjugation. The hot-wall epitaxy technique made precise control of the growth conditions possible. Atomic force microscopy and x-ray diffraction measurements demonstrated that a polycrystalline thin film with the molecules in the face-to-face configuration was obtained, and that, depending on the growth conditions, the thin-film structure was controllable. [ABSTRACT FROM AUTHOR]

We have obtained x-ray phase-contrast images with high spatial resolution by using extremely asymmetric Si 111 Bragg diffractions near the critical angle of the total reflection. The x-ray image could be magnified to 294 times in both vertical and horizontal directions. By using this x-ray microscopy system, we have observed clear phase-contrast images of a 0.7-μm-wide gold-line pattern. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Oxygen concentration in a horizontal Bridgman-grown, chromium and oxygen-doped, semiinsulating GaAs ingot was analyzed using charged particle activation analysis. The oxygen concentration ranged from 2.0 × 10[sup 15] at seed end to 7.2 × 10[sup 15] cm[sup -3] at tail end. The change of oxygen concentration measured along the length of ingot was in accordance with the normalfreeze equation. The effective distribution coefficient of oxygen was estimated to be 0.39. [ABSTRACT FROM AUTHOR]

We measure the diffraction peaks of InGaAsP selective metal-organic vapor-phase epitaxial layers on 1.7-μm-wide InP stripe regions between a pair of SiO[sub 2] mask stripes. This is achieved by using an x-ray microbeam with low angular divergence and a narrow energy bandwidth that was produced through two-dimensional condensation of undulator radiation x rays from a synchrotron light source using successive asymmetric diffraction. The lattice strain is investigated by changing the SiO[sub 2] mask width from 4 to 40 μm. The rocking curves reveal clear peak shifts in the InGaAsP layers from the higher angle side to the lower angle side of the InP substrate peaks as the mask width increases. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A blood flow noise transducer for use on the eyes has been designed to take the place of an ordinary accelerometer-type setting on the head skin. The blood flow noise is generally considered to be generated by the turbulent flow in an artery due to deformation of the vascular wall, such as an aneurysm. The present transducer is intended to detect the turbulent flow noise from the intracranial aneurysms clearly by setting the transducer on the eyes. A novel transducer has been constructed using PVDF film, which has a sensitivity of - 63 Db (V/μbar) and a bandwidth of over 2.5 kHz. In clinical applications the transducer has shown fairly good results. Simulated experiments using the transducer with a cranial model suggest that the localization of the sound source can be predicted by data processing. [ABSTRACT FROM AUTHOR]