In conclusion, an initialization method has been introduced and studied to improve the SET speed in PCM. Before experiment verification, a two-dimensional finite analysis is used, and the results illustrate the proposed method is feasible to improve SET speed. Next, the R-I performances of the discrete PCM device and the resistance distributions of a 64 M bits PCM test chip with and without the initialization have been studied and analyzed, which confirms that the writing speed has been greatly improved. At the same time, the resistance distribution for the repeated initialization operations suggest that a large number of PCM cells have been successfully changed to be in an intermediate state, which is thought that only a shorter current pulse can make the cells SET successfully in this case. Compared the transmission electron microscope (TEM) images before and after initialization, it is found that there are some small grains appeared after initialization, which indicates that the nucleation process of GST has been carried out, and only needs to provide energy for grain growth later.

Negative electron affinity (NEA) surfaces can be formed by alternating supply of alkali metals (e.g. Cs, Rb, K) and oxygen on semiconductor surfaces. We have studied adsorption structures of Cs on an As-terminated (2×4) (001) GaAs surface using scanning tunneling microscopy (STM). We found that the initial adsorption of Cs atoms occurs around the step sites in the form of Cs clusters and that the size of clusters is reduced by successive exposure to O2, indicating that As-terminated (2×4) surfaces are relatively stable compared to Ga-terminated surfaces and are not broken by the Cs clusters adsorption.

A renal biopsy is a procedure to get a small piece of kidney for microscopic examination. With the development of tissue sectioning and medical imaging techniques, microscope renal biopsy image sequences are consequently obtained for computer-aided diagnosis. This paper proposes a new context-based segmentation algorithm for acquired image sequence, in which an improved genetic algorithm (GA) patching method is developed to segment different size target. To guarantee the correctness of first image segmentation and facilitate the use of context information, a boundary fusion operation and a simplified scale-invariant feature transform (SIFT)-based registration are presented respectively. The experimental results show the proposed segmentation algorithm is effective and accurate for renal biopsy image sequence.

Ni nanodots (NDs) used as nano-scale top electrodes were formed on a 10-nm-thick Si-rich oxide (SiO$_{mathrm{x}}$)/Ni bottom electrode by exposing a 2-nm-thick Ni layer to remote H$_{2}$-plasma (H$_{2}$-RP) without external heating, and the resistance-switching behaviors of SiO$_{mathrm{x}}$ were investigated from current-voltage ( extit{I--V}) curves. Atomic force microscope (AFM) analyses confirmed the formation of electrically isolated Ni NDs as a result of surface migration and agglomeration of Ni atoms promoted by the surface recombination of H radicals. From local extit{I--V} measurements performed by contacting a single Ni ND as a top electrode with a Rh coated Si cantilever, a distinct uni-polar type resistance switching behavior was observed repeatedly despite an average contact area between the Ni ND and the SiO$_{mathrm{x}}$ as small as $sim$ 1.9 $ imes$ 10$^{-12}$cm$^{2}$. This local extit{I--V} measurement technique is quite a simple method to evaluate the size scalability of switching properties.

This paper describes a robust three-dimensional (3D) surface reconstruction method that can automatically eliminate shadowing errors. For modeling shadowing effect, a new shadowing compensation model based on the angle distribution of backscattered electrons is introduced. Further, it is modified with respect to some practical factors. Moreover, the proposed iterative shadowing compensation method, which performs commutatively between the compensation of image intensities and the modification of the corresponding 3D surface, can effectively provide both an accurate 3D surface and compensated shadowless images after convergence.

The Transition Edge Sensor (TES)-Energy Dispersive Spectrometer (EDS) is an X-ray detector with high-energy resolution (12.8 eV). The TES can be mounted to a scanning electron microscope (SEM). The TES-EDS is based on a cryogen-free dilution refrigerator. The high-energy resolution enables analysis of the distribution of various elements in samples under low acceleration voltage (typically under 5 keV) by using K-lines of light elements and M lines of heavy elements. For example, the energy of the arsenic L line differs from the magnesium K line by 28 eV. When used to analyze the spore of the Pteris vittata L plant, the TES-EDS clearly reveals a different distribution of As and Mg in the micro region of the plant. The TES-EDS with SEM yields detailed information about the distribution of multi-elements in a sample.

This paper reports on the effect of switching action on the contact surfaces of earthquake disaster prevention relays. Large-scale earthquakes occur frequently in Japan and bring extensive damage with them, and fire caused by electrical equipments is one example of the serious damage which can occur. Earthquake sensors capable of maintaining a high level of reliability when earthquakes occur play an important role as a means of minimizing this damage. For this reason, we carried out observations by focusing on samples which had either been subjected to an electric current of 10 mA or 0.1 A. The samples of 10 mA exhibited low and constant contact resistance despite the addition of seismic motion, while the samples of 0.1 A samples exhibited varying contact resistance and damage on their contact spots resulting from the addition of seismic motion. The sample surfaces were then observed using an atomic force microscope (AFM) in tapping mode and a surface potential microscope (SPoM). As a result, we found that even the unused earthquake disaster prevention relay (standard sample) which had a surface lined with asperities on its parallel striations formed by irregular protrusions due to dust and other deposits. In addition, scanning the contact surface with the SPoM at the same potential revealed the occurrence of differences in surface potential which varied in response to the asperities on the striations.

We initiated development of our own data processing software for laser microscope data with C# language. This software is provided with volume calculation function of a target portion, based on a new calculation algorithm that can precisely handle the volume calculation of the portion located on a tilted surface or on a distorted surface. In this paper, this algorithm and some exemplary results obtained thereby, as well as some further development aims, are briefly described.

The motion of arc spots of breaking arc is investigated for Ag electrical contacts in DC 42 V/10 A resistive circuit using a high-speed camera. Also, the eroded contact surfaces are observed with a microscope after each breaking operation. As results, some kinds of different films and eroded regions are distinguished. Diameters of these regions are corresponding to the widths of the cathode and anode spot regions that are obtained by using the high-speed camera. It is found that the films and eroded regions on the electrical contacts are generated at different stages of the breaking arc.

A new scheme for evaluation of shapes of pips and craters formed by arc discharges on electrical contact surfaces is proposed. Measuring a height of a pip or a depth of a crater as well as an average diameter thereof with a scanning laser microscope and then putting a plot having the measured values as its vertical and horizontal coordinates enable us to numerically and briefly evaluate shapes of those pips and craters on arc-damaged contact surfaces. Some exemplary results obtained by this evaluation scheme are presented here.

The authors have been interested in a Scanning Laser Microscope (SLM) and applied it to studies of contact phenomena. In particular, a digital SLM is being currently used, and confirmed to be a successful tool for investigating the contact phenomena. In this paper, the theory and mechanism of a digital SLM are briefly explained, and some actual data obtained with the digital SLM are presented for demonstrating its usefulness for studies of contact phenomena.

This study attempts to demonstrate that activated leukocytes are involved in vascular shut down effect (VSD) in photodynamic therapy (PDT). Hydrogen peroxide (H2O2), a reactive oxygen specie (ROS) that is found in monocytes, was visualized under a confocal laser scanning microscope, and ROS formation was quantified by fluorescence image analysis. The fluorescence intensity was expressed as a gray level graded from 0 to 255. Only the fluorescence derived from monocytes that had ZnCP-III incorporated and were irradiated with an HeNe laser caused increases in the fluorescence distribution over time, while no change of distribution was observed in three other conditions (only Zn CP-III added, only HeNe laser irradiation, or non-treated). The result indicates that the photochemical reaction induced by excitation of a photosensitizer, and ROS was derived from the reaction-stimulated monocytes. The activated monocytes generated ROS themselves and H2O2 was visualized by the DCFH fluorescence method. In conclusion, the result clearly shows that activated monocytes are involved in the VSD effect.

Micropatterning of organosilane self-assembled monolayers (SAMs) was demonstrated on the basis of photolithography using an excimer lamp radiating vacuum ultra-violet (VUV) light of 172 nm in wavelength. This lithography is generally applicable to micropatterning of organic thin films including alkyl and fluoroalkyl SAMs, since its patterning mechanism involves cleavage of C-C bonds in organic molecules and subsequent decomposition of the molecules. In this study, SAMs were prepared on Si substrates covered with native oxide by chemical vapor deposition in which an alkylsilane, that is, octadecyltrimethoxysilane [CH3(CH2)17Si(OCH3)3, ODS] or a fluoroalkylsilane, that is, 1H, 1H, 2H, 2H-perfluorodecyltrimethoxy-silane [CF3(CF2)7CH2CH2Si(OCH3)3, FAS] were used as precursors. Each of these SAMs was photoirradiated through a photomask placed on its surface. As confirmed by atomic force microscopy and x-ray photoelectron spectroscopy, the SAMs were decomposed and removed in the photoirradiated area while the masked areas remained undecomposed. A micropattern of 2 µm in width was successfully fabricated. Furthermore, microstructures composed of two different SAMs, that is, ODS and FAS, were fabricated as follows. For example, an ODS-SAM was first micropatterned by the VUV-lithography. Since, the VUV-exposed region on the ODS-SAM showed an affinity to the chemisorption of organosilane molecules, the second SAM, i. e. , FAS, confined to the photolithographically defined pattern was successfully fabricated. Due to the electron negativity of F atoms, the FAS covered region showed a more negative surface potential than that of the ODS surface: its potential difference was ca. 120 mV as observed by Kelvin probe force microscopy.

When a micromachine works inside a narrow space inside tubes and equipment such as a microfactory, a microdevice that has a visual function is indispensable. To monitor the minute shapes of microfabrication and microassembly process that are impossible to observe, fiber-optic sensors and actuators for environmental recognition devices have been developed. The devices are designed to allow stereoscopic and microscopic observation and to measure the dimensions of microparts. To achieve these goals and to realize minute structures and functions, we developed environmental recognition devices for microfabrication process with functions of far and near field observation, tactile sensing and tip articulation, for microassembly process with functions of stereoscopic observation and tip articulation. The results show that easy and safe environmental recognition is possible in the narrow spaces of a microfactory.

A portable cryo-system using a high-Tc SQUID for the measurement of the remanant magnetic field of a rock specimen was designed and fabricated. The sensing surface of the SQUID faces upward in our system, although the system for bio-magnetics faces down. The SQUID is cooled by liquid nitrogen via a sapphire heat transfer rod. The total heat transfer of the system was measured by means of a boiling-off method and was found to be 1.65 W. It was demonstrated that the system can be operated for more than 17 hours without any maintenance such as filling with liquid nitrogen. The system was applied to the measurement of the remanent magnetic field distributions of rock samples cored from deep underground. We have successfully measured the distributions.

We proposed a new thchnique using saw wave modulation light to measure the thermal diffusivity of a transparent adhesive by photoacoustic microscope. In this technique, the time required for the measurement of it can be reduced by one-fifth compared with that of a conventional method.

We studied effects of 50-200-keV electrons on semiconductor devices using BEASTLI (backscattered electron assisting LSI inspection) method. When irradiating semiconduc-tor devices with such high-energy electrons, we have to note two phenomena. The first is surface charging and the second is device damage. In our study of surface charging, we found that a net positive charge was formed on the device surface. The positive surface charges do not cause serious influence for observation so that we can inspect wafers without problems. The positive surface charging may be brought about because most incident electrons penetrate the device layer and reach the conducting substrate of the semiconductor device. For the device damage, we studied MOS devices which were sensitive to electron-beam irradiation. By applying a 400- annealing to electron-beam irradiated MOS devices, we could restore the initial characteris-tics of MOS devices. However, in order to recover hot-carrier degradation due to neutral traps, we had to apply a 900- annealing to the electron-beam irradiated MOS devices. Thus, BEASTLI could be successfully used by providing an apporopri-ate annealing to the electron-beam irradiated MOS devices.

A new electron-beam wafer inspection system has been developed. The system has a resolution of 5 nm or better, and is applicable to quarter-micron devices such as 256 Mbit DRAMs. The most remarkable feature of this system is that a specimen stage is built in the objective lens and allows a working distance (WD) of 0. "WD=0"minimizes the effect of lens aberrations, and maximizes the resolving power. Innovative designs to achieve WD=0 are as follows: (1)A large objective lens of 730-mm width 730-mm depth 620-mm height that serves as a specimen chamber, has been developed. (2)A hollow specimen stage made of non-magnetic materials has been developed.It allows the lower pole piece and magnetic coile of the objective lens inside it. (3)Acoustic motors made of non-magnetic materials are em-ployed for use in vacuum.

In clad contacts of bonded dissimilar metals used in relays and switches, the bonding state affects the switching performance of those devices. Examining the bonding state and analyzing the relationship between the bonding state and the causes of malfunction, such as welding of the contact, leads to improvement in reliability of electromechanical devices. In this experiment we examined, with an ultrasonic microscope, the bonding state in riveted clad contacts which had been subjected to load-breaks of in-rush current, and were able to demonstrate the causal relation of the bonding state with malfunctions of the contacts. The use of the ultrasonic microscope made it possible to perform a hitherto difficult detailed analysis of the bonding state of clad contacts. It was also confirmed that this was an extremely effective method for studying the relationship with switching performance.

The origin of and a method of enhancing the Optical Beam Induced Resistance Change (OBIRCH) signal for defect observation in VLSI metal interconnections is discussed based on a numerical analysis of three-dimensional thermal conduction and experimental results. The numerical analysis shows that the OBIRCH signal originates from a slight increase in the resistance of the metal line caused by laser beam heating and that its effect is influenced by the temperature of the metal layer. Both simulations and experimental results suggest that cooling the sample is preferable to detect the OBIRCH signal. The decrease in the total resistance of the metal line without any change in the amount of the resistance increase under laser illumination is found to be the main cause of the OBIRCH signal enhancement under low temperature measurement.