A5023409007- Force Microscopy Techniques and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Phase-change materials and chalcogenides
- Near-Field Optical Microscopy
- Advanced Memory and Neural Computing
- Chalcogenide Semiconductor Thin Films
- Advancements in Photolithography Techniques
- Block Copolymer Self-Assembly
- Surface and Thin Film Phenomena
- Nanofabrication and Lithography Techniques
- Mechanical and Optical Resonators
- Liquid Crystal Research Advancements
- Anodic Oxide Films and Nanostructures
- Transition Metal Oxide Nanomaterials
- Semiconductor materials and devices
- Advanced Surface Polishing Techniques
- Optical Coatings and Gratings
- Quantum Dots Synthesis And Properties
- Polymer Surface Interaction Studies
- Advanced Materials Characterization Techniques
- Advanced MEMS and NEMS Technologies
- Electron and X-Ray Spectroscopy Techniques
- Magnetic properties of thin films
- Molecular Junctions and Nanostructures
- Ion-surface interactions and analysis
Gunma University
2010-2021
Kiryu University
2003-2018
University of Electronic Science and Technology of China
2018
Nanyang Technological University
2018
Guangdong University of Technology
2018
Max Planck Institute for Informatics
2016
Graduate School USA
2016
Universiti Teknologi MARA
2015
Akita Industrial Technology Center
2010
Gunma Industrial Technology Center
2008
Although synaptic behaviours of memristors have been widely demonstrated, implementation an even simple artificial neural network is still a great challenge. In this work, we demonstrate the associative memory on basis memristive Hopfield network. Different patterns can be stored into by tuning resistance memristors, and pre-stored successfully retrieved directly or through some intermediate states, being analogous to behaviour. Both single-associative multi-associative memories realized...
We observed the surface potential of silicon pn junctions using a Kelvin probe force microscope whose sensitivity was about five times better than that conventional one. It achieved by three major improvements: electrostatic detection second cantilever resonance, Q-value enhancement operating in vacuum, and direct resonance frequency modulation technique. demonstrated made thermal diffusion varies gradually compared to those ion implantation, possibly reflecting their gradual dopant...
We study the paired-pulse-induced response of a NiOx-based memristor. The behavior memristor is surprisingly similar to paired-pulse facilitation biological synapse. When stimulated with pair electrical pulses, current induced by second pulse larger than that first pulse. In addition, magnitude decreases interval, while it increases or width.
The well-known Ebbinghaus forgetting curve, which describes how information is forgotten over time, can be emulated using a NiO-based memristor with conductance that decreases time after the application of electrical pulses. Here, analogous to memory state, while each pulse represents stimulation or learning event. decrease in depends on parameters, including height and width number pulses, emulates loss behavior well taken for lost learned.
In this study, sputtered undoped and nitrogen doped Sb2Te3 (ST STN) films were systematically investigated by x-ray diffraction (XRD) resistance measurements. Their application to lateral phase-change memory (PCM) is presented as well. The STN film at a flow rate ratio (N2∕Ar) of 0.07 proved have both high stability low power consumption, implying its performance in PCM applications. the (N2∕Ar>0.15), hexagonal Te phase first appeared 160 °C, then orthorhombic SbN 290 °C. separation...
The switching time of a Ag2S atomic switch, in which formation and annihilation Ag bridge is controlled by solid-electrochemical reaction nanogap between two electrodes, investigated as function bias voltage temperature. Increasing the decreases exponentially, with greater exponent for lower range than that higher range. Furthermore, shortens exponentially raising temperature, following Arrhenius relation activation energy values 0.58 1.32 eV ranges, respectively. These results indicate...
Phase change memory (PCM), which exploits the phase behavior of chalcogenide materials, affords tremendous advantages over conventional solid-state due to its nonvolatility, high speed, and scalability. However, power consumption PCM poses a critical challenge has been most significant obstacle widespread commercialization. Here, we present novel approach based on self-assembly block copolymer (BCP) form thin nanostructured SiOx layer that locally blocks contact between heater electrode...
A vacuum compatible Kelvin probe force microscopy (KPFM) is presented. Difficulties in operating KPFM a were overcome by utilizing the direct cantilever resonance frequency detection tip height control whereas indirect scheme was used primordial KPFM. The potential measurement sensitivity improved 14 dB compared to that air. It due increased Q value and reduction interference from signal because conducted using cantilever’s second while first resonance. silicon wafer whose surface partially...
Synaptic Long-Term Potentiation (LTP), which is a long-lasting enhancement in signal transmission between neurons, widely considered as the major cellular mechanism during learning and memorization. In this work, NiOx-based memristor found to be able emulate synaptic LTP. Electrical conductance of increased by electrical pulse stimulation then spontaneously decays towards its initial state, resembles The lasting time LTP can estimated with relaxation equation, well describes decay behavior....
Synaptic memristor has attracted much attention for its potential applications in artificial neural networks (ANNs). However useful real life with such memristor-based have seldom been reported. In this paper, an ANN based on memristors is designed to learn a multi-variable regression model back-propagation algorithm. A weight unit circuit memristor, which can be programed as excitatory synapse or inhibitory synapse, introduced. The of the electronic determined by conductance and current...
Although there is a huge progress in complementary-metal-oxide-semiconductor (CMOS) technology, construction of an artificial neural network using CMOS technology to realize the functionality comparable with that human cerebral cortex containing 10
A new type of microscope, which is based upon both a scanning tunneling microscope (STM) and technique for detecting acoustic waves, described. An wave generated in STM’s sample, by vibration its tip, detected piezoelectric transducer coupled to the sample. The amplitude corresponds strength force interaction between tip sensitive tip-sample spacing. We have been successful keeping spacing constant using feedback loop that holds this without tunneling. This method enhances features STM...
The formation and observation, with reflected light, of 60-nm-diam phase-changed domains in a thin GeSbTe film using scanning near-field optical microscope 785 nm wavelength laser diode is demonstrated. dependence the domain size on incident power was obtained, changed from 150 to 60 diameter 8.4–7.3 mW probe. At threshold 7.3 mW, temperature rose around 180 °C partially phase change local area amorphous crystalline. A detected reflectivity increase due formed 8%–2%. observing (reading)...
We present for the first time a nanometer-sized phase-change recording using scanning near-field optical microscope (PC-SNOM recording). The experiments were performed with SNOM 785-nm-wavelength semiconductor laser diode, shear force detection gap control and reflected light observing domains (reading). media of ZnS·SiO 2 (20 nm)/GeSbTe(30 nm)/ZnS·SiO (150 nm)/polycarbonate substrate used. writings done at powers 8.4–7.3 mW in probe pulse widths 5 or 0.5 ms. As result, we obtained minimum...
Au-adsorbed structures (∼1 ML) on the Si(111) surface are studied using a scanning tunneling microscope. In initial stage of deposition, locally Au atoms adsorbed onto with 5×5 periodicity. At lower coverage, images showing 5×2 periodicity recorded, in which there dark line and two atomic rows running [1̄01] direction five times period. each row, arranged period along row. higher (3)1/2×(3)1/2 structure also recorded. these images, addition to (3)1/2 ×(3)1/2 periodicity, is an undulation...
Si pn junctions fabricated by photoresist masked As+ implantation were observed using current imaging tunneling spectroscopy (CITS) in a scanning microscope (STM). Using the CITS, specific bias was chosen to define n-type or p-type areas according whether not flowed. The could be easily identified from image at this and STM topographic image. It also proved possible find processing faults related implantation. images structure (corrugations) near junctions, associated with volume expansion...
A confined-chalcogenide (CC) cell structure for reducing the reset current of phase-change random access memory (PRAM) is proposed in this investigation. Both single normal-bottom-contact (NBC) (for reference) and CC PRAM cells are simulated by two-dimensional finite element modelling. The amorphous region NBC after operation generally a semiellipse, which agrees very well with reported experimental results. has rectangular operation. much lower than that cell. needs low power consumption...
We studied the electrical properties of 20- and 50-nm-thick Ge 2 Sb Te 5 AgInSbTe films for nonvolatile lateral transistor memory devices. Both kinds thin were prepared as film samples device which then annealed at temperatures from 140 to 415°C. It is known that crystal size can be effectively reduced with thickness on basis X-ray diffraction analysis. The resistances all 140–415°C decreased by approximately 5–6 orders magnitude. In case samples, however, source-drain first reversely...
The dynamic process of Si crystal growth on a Si(111)7\ifmmode\times\else\texttimes\fi{}7 surface was studied in situ using high-temperature scanning tunneling microscopy. evaporated onto surface, kept at 350 \ifmmode^\circ\else\textdegree\fi{}C, and the observed. step-flow observed as appearance new adatoms step edge. [112\ifmmode\bar\else\textasciimacron\fi{}] steps became jagged with [1\ifmmode\bar\else\textasciimacron\fi{} 1\ifmmode\bar\else\textasciimacron\fi{} 2] steps. At steps,...
Nanometer recording has been demonstrated with tens nanometer diameter pits and gold mounds formed on graphite Si substrate using an atomic force microscope at atmospheric pressure. The probe is prepared by means of coating thin film SiO 2 birdbeak-type cantilever probe, fabricated a microprocess. Applications voltage pulses between the make about 10-nm Au mounds. Furthermore, 50-nm to 30-nm mound formations wafer covered natural silicon oxide are also demonstrated. results indicate that...