基本情報
- 所属
- 国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 特任教授
- 学位
- 工学博士(早稲田大学)工学修士
- J-GLOBAL ID
- 200901096979972445
- researchmap会員ID
- 1000192906
学歴
2-
- 1983年
-
- 1981年
委員歴
14受賞
6論文
61-
Journal of Evolving Space Activities 1 2024年4月 査読有り
-
Journal of Evolving Space Activities 1 2023年12月 査読有り
-
IEEE Transactions on Nuclear Science 1-1 2023年
-
2022 IEEE International Reliability Physics Symposium (IRPS) 2022年3月27日
-
The Journal of Physical Chemistry C 125(24) 13131-13137 2021年6月24日
-
IEEE Transactions on Nuclear Science 651 2021年 査読有り
-
Japanese Journal of Applied Physics 59(10) 106501-106501 2020年10月1日
-
Quantum Beam Science, 4 15-1-15-9 2020年3月 査読有り最終著者
-
IEEE Transactions on Nuclear Science 67(1) 328-335 2020年1月
-
The Journal of Physical Chemistry Letters 10(22) 6990-6995 2019年11月21日
-
IEEE Transactions on Device and Materials Reliability 19(4) 751-756 2019年11月 査読有り最終著者
-
IEEE Transactions on Nuclear Science 66(1) 155-162 2019年11月 査読有り
-
2018 IEEE SOI-3D-Subthreshold Microelectronics Technology Unified Conference, S3S 2018 2019年2月11日Institute of space and astronautical science (ISAS) succeeded in orbit injection of a space satellite in 1970, which was the fourth in the world. After then we launched more than 30 space satellites including space probes. One of the space probes, named HAYABUSA, lunched in 2003 and returned to the earth with small amount of sands on a small asteroid named ITOKAWA in 2010 [1], which is an outstanding achievement succeeding to Apollo's great achievement in USA that gathered the mineral of the moon. Since then, exploration of planets and asteroids is one of important missions in ISAS. Presently, HAYABUSA-2 is on an orbit and is exploring another type of asteroids named RYUGU. To achieve more innovative missions in a deep space, advanced LSIs with both high radiation tolerance against harsh environment [2] and low power consumption are strongly required. For this purpose, we are in charge of research and development of LSIs as well as electronic devices used for space science mission. For example, we have been studying radiation effects on advanced devices promising for space science including the SOI devices, spintronics devices [3], [4], and perovskite solar cells [5].
-
IEEE Transactions on Device and Materials Reliability 18(4) 574-582 2018年12月 査読有り最終著者
-
Applied Physics Letters 113(18) 2018年10月29日 査読有り© 2018 Author(s). Organic solar cells have attractive potential for space applications as they have very high specific power (power generated per weight) and ultra-high flexibility (to reduce stowed volume). However, one critical issue is whether they are stable under the harsh space environment, particularly their stability under high energy, high flux, electron and proton bombardment. In this paper, the stability of benchmark organic photovoltaic layers under proton bombardment (150 keV with a fluence of 1 × 1012/cm2) and electron bombardment (1 MeV with a fluence of 1 × 1013/cm2) under vacuum is investigated. Raman spectroscopy, photoluminescence spectroscopy, and optical reflectance spectroscopy are applied to study their chemical/structural, photo-chemical/morphological, and optical stability after the bombardments. The results show that all the benchmark organic photovoltaic films are stable under the radiation, implying that organic solar cells could be feasible for space applications.
-
IEEE Transactions on Nuclear Science 65(8) 1900-1907 2018年8月
-
ISCIENCE 2 148-+ 2018年4月Materials to be used in the space environment have to withstand extreme conditions, particularly with respect to cosmic particle irradiation. We report robust stability and high tolerance of organolead trihalide perovskite solar cells against high-fluence electron and proton beams. We found that methylammonium and formamidinium-based lead iodide perovskite solar cells composed of TiO2 and a conductive polymer, as electron and hole transport materials, can survive against accumulated dose levels up to 10(16) and 10(15) particles/cm(2) of electrons (1MeV) and protons (50 KeV), respectively, which are known to completely destroy crystalline Si-, GaAS-, and InGaP/GaAs-based solar cells in spacecraft. These results justify the superior tolerance of perovskite photovoltaic materials to severe space radiations and their usefulness in satellite missions.
-
Journal of Astronomical Telescopes, Instruments, and Systems 4(2) 021402-1-021402-13 2018年4月 査読有り
-
Physica B: Condensed Matter 532 99-102 2018年3月1日 査読有りThe breakdown electric field of several SiC polymorphs has been investigated theoretically using a concept of “recovery rate,” which is obtained by first principles calculations. A good relationship between the experimental breakdown electric fields and the calculated recovery rate of 4H-, 6H-, and 3C-SiC was obtained. In order to examine the stability of SiC polymorphs, the total electronic energies of various types of SiC crystal structures were calculated. Here, two candidates of polymorphs—GeS-type- and 2H-SiC—with energies comparable to those of experimentally well-established structures, have been obtained. The breakdown electric fields of these two polymorphs were estimated using a relationship obtained from the results of 4H-, 6H-, and 3C-SiC. This indicates that one of these polymorphs, GeS-type-SiC, has higher breakdown electric field than any other SiC polymorphs. In addition to the investigation with the recovery rate, relationship between experimental breakdown electric field and calculated band gap with recently developed accurate electron-correlation potential has been also discussed.
-
IEEE Transactions on Nuclear Science 65(1) 346-353 2018年1月1日 査読有りAn interesting multiple-cell upset (MCU) phenomenon in silicon-on-insulator (SOI) static random access memorys (SRAMs) featuring long lines of more than ten flipped cells is studied. Such an abnormal MCU phenomenon was recently observed for back-biased SOI SRAMs in a heavy-ion test. Using a two-photon absorption-based laser system, we performed fixed-point observations and visualized the development of long line-type MCUs with increasing back bias. The visualization results provided insights to elucidate the mechanism behind these phenomena. Furthermore, using fixed-point observations, we extracted the length of MCUs for various bias conditions and laser strike positions. It was found that for all cases studied, the line length could be explained using an analytical model.
-
IEEE Transactions on Nuclear Science 65(1) 523-532 2018年1月1日 査読有りSilicon-on-insulator technology is often used to develop high-reliability devices with low sensitivity to single-event upsets or soft errors. Its key component, the buried-oxide (BOX) layer, is now thinned down to 10 nm. This thinning enables transistors on the layer to be efficiently conditioned by back-bias voltages fed underneath the layer. However, a little is known about the influence of such conditioning on the sensitivity to soft errors caused by heavy ion radiation. A static random access memory supported by a 10-nm-thick BOX layer was exposed to high-energy heavy ions. Back-bias voltages were fed to the memory cells through a triple well structure fabricated underneath the BOX layer. The applied back-bias conditioning led to a 100-fold increase in the soft-error sensitivity compared with the counterpart zero-bias condition. In addition, interesting line patterns of the upset cells were revealed on the memory floor. These findings are contrary to previous results in neutron and alpha-particle tests. Analyses and modeling as well as supplementary gamma-ray total ionizing dose tests suggest that they are caused by a new soft-error mechanism. Back-bias conditioning may increase perturbations in potential under the BOX layer, which are originally induced by respective single heavy-ion strikes. Each perturbation may spread under the layer and cause multiple cells on the layer to be upset via the capacitance coupling principle.
-
JAPANESE JOURNAL OF APPLIED PHYSICS 56(8) 2017年8月The influences of various types of high-energy heavy-ion radiation on 10-nm-scale CoFeB-MgO magnetic tunnel junctions with a perpendicular easy axis have been investigated. In addition to possible latent damage, which has already been pointed out in previous studies, high-energy heavy-ion bombardments demonstrated that the magnetic tunnel junctions may exhibit clear flips between their high-and low-resistance states designed for a digital bit 1 or 0. It was also demonstrated that flipped magnetic tunnel junctions still may provide proper memory functions such as read, write, and hold capabilities. These two findings proved that high-energy heavy ions can produce recoverable bit flips in magnetic tunnel junctions, i.e., soft errors. Data analyses suggested that the resistance flips stem from magnetization reversals of the ferromagnetic layers and that each of them is caused by a single strike of heavy ions. It was concurrently found that an ion strike does not always result in a flip, suggesting a stochastic process behind the flip. Experimental data also showed that the flip phenomenon is dependent on the device and heavy-ion characteristics. Among them, the diameter of the device and the linear energy transfer of the heavy ions were revealed as the key parameters. From their dependences, the physical mechanism behind the flip was discussed. It is likely that a 10-nm-scale ferromagnetic disk loses its magnetization due to a local temperature increase induced by a single strike of heavy ions; this demagnetization is followed by a cooling period associated with a possible stochastic recovery process. On the basis of this hypothesis, a simple analytical model was developed, and it was found that the model accounts for the results reasonably well. This model also predicted that magnetic tunnel junctions provide sufficiently high soft-error reliability for use in space, highlighting their advantage over their counterpart conventional semiconductor memories. (C) 2017 The Japan Society of Applied Physics
-
JAPANESE JOURNAL OF APPLIED PHYSICS 56(8) 2017年8月 査読有りThis work represents the first-ever investigation of the effects of fast neutron exposure on the perpendicular-anisotropy CoFeB-MgO magnetic tunnel junctions (p-MTJs) with practical junction diameters (D) between 46 and 64 nm. In this study, 461 p-MTJs, each with a tunnel magnetoresistance (TMR) ratio above 90%, were irradiated with fast neutrons at a total 1 MeV equivalent fluence of 3.79 x 10(12)cm(-2), corresponding to 1.90 x 10(11) h irradiation with fast atmospheric neutrons (20cm(-2) h(-1)), without applying a bias voltage. Following irradiation, there were no changes in the properties of these devices, such as their resistance versus magnetic field curves, resistance values in the parallel and anti-parallel states, or TMR ratios, regardless of the neutron fluence. On the basis of these data, the nuclear reactions that occur under the specific experimental neutron irradiation conditions employed in this work are discussed. (C) 2017 The Japan Society of Applied Physics
-
2017 17th European Conference on Radiation and Its Effects on Components and Systems, RADECS 2017 2017年7月2日Silicon-on-insulator (SOI) technology has been considered capable of developing devices with high tolerance against soft error. With a thin buried oxide (BOX) layer, reduction in power consumption can be achieved by applying a back bias from under the BOX. Such power reduction is one of its many advantages and is appealing to space applications. Recently, it was found during a heavy ion experiment that a static random access memory (SRAM) fabricated with a thin-BOX SOI technology exhibits a 100-fold soft error sensitivity when it receives a back-bias. This is due to long line-type formation of multiple cell upsets (MCUs). To understand the mechanism of this phenomenon and the effects of device parameters on it, an analytical model is developed and studied with numerical simulation. On the basis of the model, a countermeasure is also discussed. It is found that the deep n-well doping concentration or resistance plays an important role in the phenomenon and its countermeasure.
-
2017 17th European Conference on Radiation and Its Effects on Components and Systems, RADECS 2017 2017年7月2日There have been no studies to date estimating the quantitative relation between the increase of interface traps and SiH groups in silicon dioxide films for the effects of total ionizing dose including enhanced low-dose-rate sensitivity (ELDRS). In this study, SiH groups densities in silicon dioxide films are measured and compared with interface trap densities developed at different dose rates to evaluate the impacts of direct proton release mechanism on ELDRS by X-ray photoelectron spectroscopy (XPS) analysis with the combined use of gamma-ray and electron-beam irradiation. The measurement results in this study clearly show that ELDRS depends linearly on SiH groups densities. The linear relationship demonstrates ELDRS is caused by the direct proton release mechanism. The order of magnitude of ELDRS we observed is almost the same as the experimental results reported previously. We emphasize that our results provide the first experimental evidence that the direct proton release mechanism is a critical mechanism affecting ELDRS in addition to the space charge model and H2 cracking.
-
JAPANESE JOURNAL OF APPLIED PHYSICS 56(4) 2017年4月 査読有りStudied is the soft error issue, which is a circuit malfunction caused by ion-radiation-induced noise currents. We have developed a laser-based soft-error simulation system to emulate the noise and evaluate its reproducibility in the time domain. It is found that this system, which utilizes a two-photon absorption process, can reproduce the shape of ion-induced transient currents, which are assumed to be induced from neutrons at the ground level. A technique used to extract the initial carrier structure inside the device is also presented. (C) 2017 The Japan Society of Applied Physics
-
JOURNAL OF APPLIED PHYSICS 121(8) 085501 2017年2月 査読有りThe effects of soft X-ray exposure on structures of CH3NH3PbI3 perovskite were investigated using an X-ray photoelectron spectroscopy (XPS) time-dependent measurement method. A crystalline sample was fabricated with the inverse-temperature crystallization method. The time evolutions of the core-level and valence-band spectra were recorded to determine the compositional ratios and valence band electronic structure of the sample, respectively. In addition, first-principles calculations were conducted to evaluate the valence band XPS spectra. The in situ XPS analysis combined with theoretical calculations demonstrated a degradation of the surface of CH3NH3PbI3 perovskite into PbI2 owing to the evaporation of methylammonium iodide.
-
2017 IEEE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM (IRPS) 2017年 査読有りSilicon-on-insulator (SOI) SRAMs supported by a thin buried-oxide (BOX) film have been exposed to wide-range high-energy heavy ions for simulating terrestrial and galactic radiation impacts. Experimental results have demonstrated that a back-bias approach leads to a 100-times increase in their soft-error sensitivity compared to the counterpart zero-bias situation. This is attributed to that back biasing may enhance radiation-induced potential fluctuation under BOX, which may spread and cause multi-cell errors in the top SOI circuits via the capacitance coupling principle.
-
IEEE TRANSACTIONS ON NUCLEAR SCIENCE 64(1) 406-414 2017年1月 査読有りThe impact of semiconductor process scaling on the overall transient response of SiGe BiCMOS platforms is investigated. Pulsed-laser two-photon absorption (TPA) and heavyion broad-beam testing of SiGe HBT device and digital test structures across several generations of SiGe technologies are utilized to investigate the potential impacts of semiconductor process scaling (e. g., lateral/vertical scaling, changes in doping, Ge content, etc.) on the overall transient shape, magnitude, and duration. Technology scaling is shown to increase the single-event effect (SEE) sensitivity of SiGe HBTs (i. e., elevated collected charge, where 1st Gen. Q(C) < 3rd Gen. Q(C) < 4th Gen. Q(C)). Modern third-generation and fourth-generation devices under a forward-active bias (i. e., forward-biased EB junction, reverse-biased CB junction) exhibit a large diffusive transient component between the emitter and collector terminals, driving an elevation in collected charge. 3-D TCAD modeling is utilized to understand the fundamental transient mechanisms and assess the primary scaling factors affecting SEE sensitivity. Ion-strike simulations show that bulk traps can substantially enhance the charge collection mechanisms within these devices. These results suggest that SiGe technology scaling may have a strong impact on the radiation-induced transient response of SiGe HBTs, with future SiGe technology generations potentially exhibiting increased sensitivities to single-event effects.
-
2016 IEEE 43RD PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC) 1657-1660 2016年 査読有りSoft X-ray exposure effects on CH3NH3PbI3 perovskite in a patterned device sample with a similar structure to solar cells, a promising candidate for X-ray detectors, have been investigated with an X-ray Photoelectron Spectroscopy (XPS) time-dependent measurement method. Our experimental analyses demonstrate compositional change from CH3NH3PbI3 to PbI2 due to evaporation of methylammonium iodide.
-
SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY 9905 2016年 査読有り
-
2015 IEEE 42nd Photovoltaic Specialist Conference, PVSC 2015 2015年12月14日 査読有りPerovskite solar cells are a candidate for use as space solar cells, and their radiation response is studied here for the first time. Perovskite solar cells are fabricated on a quartz substrate to prevent substrate degradation, which might otherwise affect the evaluation of radiation tolerance of the cells. As a result, superior radiation tolerance of perovskite solar cells is indicated from the comparison of output performance of the cells before and after 1-MeV electron irradiation with fluence as high as 1 × 1016 cm-2. The short-circuit current, open-circuit voltage, and external quantum efficiency do not deteriorate under electron irradiation. These results suggest that perovskite solar cells are likely to be useful for space application.
-
IEEE TRANSACTIONS ON NUCLEAR SCIENCE 61(4) 1710-1716 2014年8月 査読有りA non-volatile memory element called a perpendicular-anisotropy magnetic tunnel junction was fabricated using CoFeB/MgO/CoFeB film stack technology. It exhibits two stable resistance values, high or low, depending on the relative directions of the magnetizations of the two ferromagnetic CoFeB layers. After being programmed into the high resistance state with a current injection scheme based on the spin transfer torque theory, the tunnel junction was exposed to 15-MeV Si ions under different voltage stress conditions. The tested structure remained in the programmed high resistance state after being bombarded with 10-100 Si ions, even under the stressed situations. A time-domain analysis proved that this result is due to the perfect immunity of the tested magnetic tunnel junction to single event upsets. Some degradation in resistance due to the heavy-ion irradiation was detected through a precise parameter analysis based on a tunneling theory but it was negligibly small (1%). There were no statistically significant changes in the thermal stability factor before and after irradiation, and this means the long-term retention properties remained unchanged.
-
Proceedings of SPIE - The International Society for Optical Engineering 9144 2014年 査読有り© 2014 SPIE.The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions developed by the Institute of Space and Astronautical Science (ISAS), with a planned launch in 2015. The ASTRO-H mission is equipped with a suite of sensitive instruments with the highest energy resolution ever achieved at E > 3 keV and a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. The simultaneous broad band pass, coupled with the high spectral resolution of ΔE ≤ 7 eV of the micro-calorimeter, will enable a wide variety of important science themes to be pursued. ASTRO-H is expected to provide breakthrough results in scientific areas as diverse as the large-scale structure of the Universe and its evolution, the behavior of matter in the gravitational strong field regime, the physical conditions in sites of cosmic-ray acceleration, and the distribution of dark matter in galaxy clusters at different redshifts.
-
MICRO- AND NANOTECHNOLOGY SENSORS, SYSTEMS, AND APPLICATIONS V 8725 2013年 査読有りDevelopment of semiconductor devices not only for harsh radiation environments such as space but also for ground-based applications now faces a major hurdle of radiation problems. Necessary is protecting chips from malfunctions due to sub-nanosecond transient noises induced by radiation. As a protection technique using the silicon-on-insulator structure is often suggested, but the use in fact requires devices and circuits carefully optimized for maximizing its benefits. Mainly describing theoretical and experimental characterization of the transient effects, this paper presents a comprehensive study on radiation responses of commercial silicon-on-insulator technologies, which study results in a space-use low-power system-on-chip with a 100-MIPS RISC-based core.
-
2013 14TH EUROPEAN CONFERENCE ON RADIATION AND ITS EFFECTS ON COMPONENTS AND SYSTEMS (RADECS) 2013年 査読有りA non-volatile memory element that is called a perpendicular- anisotropy magnetic tunnel junction has been fabricated in a CoFeB/MgO/CoFeB film stack technology. It exhibits two stable resistance values, high or low, depending on the relative direction of magnetization of the two ferromagnetic CoFeB layers. After programmed into the high resistance state with a current injection scheme based on the spin transfer torque theory, the tunnel junction has been exposed to 15-MeV Si ions in different voltage stress conditions. It has been observed that the tested structure remains in the programmed high resistance state after received the bombardments of several tens of Si ions and more, even under the stressed situations. A time- domain analysis has proven that this result is due to the perfect immunity of the tested magnetic tunnel junction to single event upsets. A resistance degradation due to the heavy-ion irradiation has been detected through a precise parameter analysis based on a tunneling theory but negligibly small, 1%.
-
Publications of the Astronomical Society of the Pacific 124(918) 823-829 2012年8月 査読有りWe have evaluated the optical and electrical properties of a far-infrared (IR) transparent electrode for extrinsic germanium (Ge) photoconductors at 4 K, which was fabricated by molecular beam epitaxy (MBE). As a far-IR transparent electrode, an aluminum (Al)-doped Ge layer is formed at well-optimized doping concentration and layer thickness in terms of the three requirements: high far-IR transmittance, low-resistivity, and excellent ohmic contact. The Al-doped Ge layer has the far-IR transmittance of > 95% within the wavelength range of 40-200 μm, while low-resistivity (~5 Ωcm) and ohmic contact are ensured at 4 K. We demonstrate the applicability of the MBE technology in fabricating the far-IR transparent electrode satisfying the above requirements. © 2012. The Astronomical Society of the Pacific. All rights reserved.
-
JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA 185(5-7) 129-132 2012年8月 査読有りThe valence states of the Mn ions in Pr(1-x)A(x)MnO(3-delta) (A = Ca, Sr) are investigated by Mn-L-3 X-ray absorption near-edge structure (XANES) analysis. The spectral fine structures in the Mn-L-3 XANES analysis show a significant difference between Pr0.5Ca0.5MnO3-delta and Pr0.5Sr0.5MnO3-delta, a paramagnetic insulator and a ferromagnetic metal, respectively, at room temperature, whereas the spectral structures of Pr0.7Ca0.3MnO3-delta and Pr0.7Sr0.3MnO3-delta, paramagnetic insulators, are almost identical. These results indicate that the valence states of the Mn ions in these materials are highly correlated with their magnetic and electrical properties. A significant difference was also found between the Mn-L-3 XANES profiles of Pr1-xCaxMnO3-delta and the profiles formed by the linear combination of the Mn-L-3 XANES spectra of PrMnO3 (Mn3+) and CaMnO3 (Mn4+). This difference indicates that the Mn ions in these materials do not have a mixed-valence state of 3+ and 4+, but have an intermediate valence state o 3+ and 4+. (c) 2012 Elsevier B.V. All rights reserved.
-
JAPANESE JOURNAL OF APPLIED PHYSICS 51(4) 2012年4月 査読有りTo achieve metal-oxide-semiconductor field-effect transistors (MOSFETs) with high reliability, it is important to investigate the dielectric breakdown of gate oxide films of MOSFETs. It is known that dielectric breakdown is usually due to the presence of defects in films. Estimating the breakdown electric-field strength while reflecting local structures such as defects is important for investigation of the reliability of gate SiO2 films. In this study, we introduce the "recovery rate'', which is a parameter potentially capable of estimating the breakdown electric-field strength while reflecting the local structures of the film. The recovery rate has a strong correlation with the breakdown electric-field strength of bulk Si and Al compounds. Using this correlation, we estimate the breakdown electric-field strength of SiO2 with oxygen vacancies and strains. (C) 2012 The Japan Society of Applied Physics
-
Proceedings of SPIE - The International Society for Optical Engineering 8443 2012年 査読有りThe joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the highenergy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-Throughput spectrometer sensitive over 0.3-12 keV with high spectral resolution of ?E 5 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5-80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40-600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes. © 2012 SPIE.
-
IEEE TRANSACTIONS ON NUCLEAR SCIENCE 58(3) 800-807 2011年6月 査読有りProton irradiation effects on fin-type field effect transistors (FinFETs) are examined from the viewpoint of their electrical-performance parameter of mobility. They are fabricated with various types of combination of strain/stress techniques to control their mobilities. The base stress level is globally modified by means of nonstrained or strained silicon-on-insulator wafers. Some process splits, additionally, receive a local strain tuning with a contact-etch-stop layer (CESL). Both n- and p-type FinFETs are evaluated. A 60-MeV proton irradiation with a fluence of 10(12) p/cm(2) leads to mobility changes for wide-fin samples: degradation for n-type and enhancement for p-type. These mobility variations can be explained with a change in the number of charged interface traps at the Si and buried-oxide interface. Narrow-fin devices exhibit mobility changes unnoticeable statistically. A comparison with previous studies indicates an elevated source/drain structure plays a role in this mobility preservation. Although the mobility is kept intact in the narrow-fin samples, a close investigation based on a two channel-component model can reveal noticeable mobility variations at a component level. In this study, observed mobility changes are complex depending on the adopted stress techniques as well as process parameters and cannot be explained by the stress levels simply.
-
Proceedings of the European Conference on Radiation and its Effects on Components and Systems, RADECS 150-155 2011年 査読有りWe designed a phase-locked loop (PLL) operating at 200 MHz using 0.2 μm fully depleted silicon-on-insulator (SOI) technology. By SPICE simulation with an appropriate single-event transient (SET) model, we achieved a radiation-hardened PLL that does not cause a SET upset upon ion irradiation with a linear energy transfer (LET) of 50 MeV-cm 2/mg at an areal penalty of 75%. © 2011 IEEE.
-
ADVANCED SEMICONDUCTOR-ON-INSULATOR TECHNOLOGY AND RELATED PHYSICS 15 35(5) 201-210 2011年 査読有りA comprehensive study on radiation-induced pulse noises in SOI CMOS logic is reviewed. The noise pulses are called single event transients or SETs and becoming a serious source of soft errors in logic systems. As a result of miniaturization of transistors, concern about the soft error problems caused by the SETs are growing not only in special applications for harsh radiation environments like space but also in usual ones used on the ground. It is important to reveal what the SET is in its nature. Measurement techniques and analytical model have been developed for the purpose. They are introduced together with experimental data obtained with test circuits fabricated by a commercial 0.2-mu m fully-depleted SOI technology. Issues to be solved for use of SOI technologies in realizing radiation hardened devices are also described with a practical example, or a development process of radiation hardened SOI SRAMs.
-
ECS Transactions 33(11) 191-202 2010年 査読有りSiGe epitaxial layers receiving sub-melt laser annealing after Carbon and Boron co-implantations are investigated. Their electrical properties have been evaluated in the reverse bias region of the IV and CV characteristics of SiGe/Si diode structures. Large dc leakage currents and frequency-dependent capacitance dispersions are observed. They are indicating the presence of electrically active defects in the studied devices. Combined IV and CV analysis suggests that the defectivity of the B-induced end-of-range defects can be enhanced by the laser treatment. This laser-driven enhancement can be suppressed by the C co-implantations. Experimental results also indicate that this C treatment is strongly affected by the laser annealing conditions. ©The Electrochemical Society.
-
Conference Record of the IEEE Photovoltaic Specialists Conference 1112-1117 2010年 査読有りThe Japan Aerospace Exploration Agency has been developing the Mercury Magnetospheric Orbiter (MMO), which is Japanese part of the BepiColombo mission. During its mission around Mercury, the spacecraft will be exposed to high solar irradiance of up to 11 suns, with an estimated maximum solar panel temperature of 230°C. In such an environment, solar cells are required to operate under high intensity and high temperature (HIHT) conditions. Therefore, it is necessary to evaluate the durability of solar cells to meet the power requirements throughout the mission life. We conducted a continuous operation test under HIHT conditions to examine the validity of the solar array configuration, using the interior planetary thermal vacuum chamber. Our HIHT tests clarified the following facts: (i) Transparency of the coverglass and the performance of the solar cells do not degrade and (ii) transparency of the DC93-500 adhesive in the top cell response region degrades mainly due to ultraviolet exposure at high temperatures. We decided to use AR0213 coverglass (from JDSU) with a thickness of 300 μm, which have a longer cut-on wavelength in ultraviolet region. With this configuration, the predicted decrease in Pmax due to the HIHT environment is 17.3% and that due to radiation effects is 11.0% Our new design will offer the available power at EOL of 394.2 W, which is 46.7 W greater than the required power. © 2010 IEEE.
-
REPORT OF RESEARCH CENTER OF ION BEAM TECHNOLOGY, HOSEI UNIVERSITY, SUPPL NO 28 28 35-40 2010年 査読有りSET-induced soft-error rates (SERSET) in logic LSIs are estimated from SET pulse-widths measured in logic cells used in logic LSIs. The estimated rates are consistent with directly measured SERSETS for logic LSIs.
-
PHYSICAL REVIEW B 81(4) 2010年1月 査読有りChemical trends of Schottky barrier heights of ten kinds of metal contacts on hydrogen-terminated diamond (001) surfaces are estimated from the temperature dependence of their current-voltage characteristics. In addition to the measurements, the interface of the metal/hydrogen-terminated diamond is theoretically modeled including the carrier density of the surface conductive layer and the electron-affinity variation from the clean surface of the hydrogen-terminated diamond. Based on the model, a relation among the carrier density, the electron affinity variation, and the barrier heights are derived. The relation explains well experimental results of and other than the present work.
-
IEEE TRANSACTIONS ON NUCLEAR SCIENCE 55(4) 1947-1952 2008年8月 査読有りA scan flip-flop (FF) is designed to observe both single event transient (SET) and single event upset (SEU) soft errors in logic VLSI systems. The SET and SEU soft errors mean the upset caused by latching an SET pulse that originates in combinational logic blocks and the upset caused by a direct ion hit to the FF, respectively. An irradiation test method using the scan FF is proposed to obtain SET and SEU soft-error rates at each FF distributed in logic VLSI systems. A test chip is designed using a 0.2-mu m fully-depleted silicon-on-insulator standard cell library. The basic concepts have been validated with Verilog timing simulations. The cell-level implementation costs of the proposed scan FF are estimated to be reasonable.
-
Proceedings of the European Conference on Radiation and its Effects on Components and Systems, RADECS 169-174 2008年 査読有りA new technique is developed to precisely measure the width of propagating voltage transients induced by irradiation of inverter chains. The technique is based on the measurement of the supply current in a detection inverter. © 2008 IEEE.
MISC
284-
JAPANESE JOURNAL OF APPLIED PHYSICS 56(8) 2017年8月The memory reliability of magnetic tunnel junctions has been examined from the aspect of their potential use in disaster-resilient computing. This computing technology requires memories that can keep stored information intact even in power-cut emergency situations. Such a requirement has been quantified as a score of acceptable flip probability, which is the failure in time (FIT) rate of 1 for a single-interface perpendicular magnetic tunnel junction (p-MTJ) with a disk diameter of 20 nm. For comparison with this acceptable probability, p-MTJ memory reliability has been evaluated. The risk of particle radiation bombardments, i.e., alpha particles and neutrons-the well-known soft error sources on the ground-has been evaluated from the aspects of both frequency of bombardments and the hazardous effects of bombardments. This study highlights that high-energy terrestrial neutrons may lead to soft errors in p-MTJs, but the flip probability, or the risk, is expected to be lower than 1 x 10(-6) FIT/p-MTJ, which is much smaller than the target probability. It has also been found that the use of p-MTJs can reduce the risk by three orders of magnitude compared with that of the conventional SRAMs. Few risks have been suggested for other radiation particles, such as alpha particles and thermal neutrons. (C) 2017 The Japan Society of Applied Physics
-
2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) 2161-2165 2014年This paper presents analysis results for the onorbit performance of a solar array paddle of the X-ray astronomy satellite Suzaku. The current generated by the solar array was decreasing significantly for approximate one year after mid-2011. We estimated the degradation of the output by simulating the on-orbit environment according to the JPL prediction method. The analysis results indicate that the on-orbit degradation of the solar array paddle is greater than the predicted performance degradation in a space environment. We determined that the difference between the on-orbit data and the analysis results could be attributed to either an increase in cell temperature or radiation degradation due to solar flares.
書籍等出版物
8講演・口頭発表等
34-
33rd International Symposium on Space Technology and Science 2022年
-
33rd International Symposium on Space Technology and Science 2022年
-
International Symposium on Solar Energy and Efficient Energy Usage (11th SOLARIS 2021) 2021年9月29日
-
The 30th International Photovoltaic Science and Engineering Conference (PVCEC-30) 2020年11月11日
-
2019 International Workshop on DIELECTRIC THIN FILMS FOR FUTURE ELECTRON DEVICES -SCIENCE AND TECHNOLOGY- (IWDTF 2019) 2019年11月18日
所属学協会
1共同研究・競争的資金等の研究課題
16-
日本学術振興会 科学研究費助成事業 基盤研究(C) 2017年4月 - 2020年3月
-
日本学術振興会 科学研究費助成事業 基盤研究(C) 2014年4月 - 2017年3月
-
文部科学省 「未来社会実現のための ICT 基盤技術の研究開発」 「イノベーション 創出を支える情報基盤強化のための新技術開発」委託研究 2012年 - 2016年
-
日本学術振興会 科学研究費助成事業 2012年4月 - 2015年3月
-
日本学術振興会 科学研究費助成事業 基盤研究(B) 2009年 - 2011年
● 指導学生等の数
1-
年度2018年度(FY2018)博士課程学生数東大生 1名修士課程学生数東大生 2名受託指導学生数2名技術習得生の数3名
● 指導学生の表彰・受賞
1-
指導学生名東口 紳太郎所属大学東京大学受賞内容（タイトル、団体名等）the 2017 RADECS sponsorship受賞年月日2017.10
● 指導学生の顕著な論文
12-
指導学生名萩本賢哉所属大学東京大学著者名, ジャーナル名, 巻号ページ（出版年）Y. Hagimoto, H. Fujioka, M. Oshima , and K. Hirose, Applied Physics Letters, 77(25), pp. 4175-4177 (2000)論文タイトルCharacterizing carrier-trapping phenomena in ultrathin SiO2 films by using the x-ray photoelectron spectroscopy time-dependent measurementsDOIhttp://doi.org/10.1063/1.1334657
-
指導学生名榎本貴志所属大学名古屋大学著者名, ジャーナル名, 巻号ページ（出版年）T. Emoto,, K. Akimoto, A. Ichimiya, K. Hirose, Applied Surface Science, 190(1-4), pp. 113-120 (2002)論文タイトルStrain due to nickel diffusion into hydrogen-terminated Si(1 1 1) surfaceDOIhttps://doi.org/10.1016/S0169-4332(01)00852-2
-
指導学生名高橋健介所属大学武蔵工業大学著者名, ジャーナル名, 巻号ページ（出版年）K. Takahashi, H. Nohira, K. Hirose, and T. Hattori, Applied Physics Letters 83(16), pp. 3422-3424 (2003)論文タイトルAccurate determination of SiO2 film thickness by x-ray photoelectron spectroscopyDOIhttps://doi.org/10.1063/1.1616204
-
指導学生名柳川善光所属大学東京大学著者名, ジャーナル名, 巻号ページ（出版年）Y. Yanagawa, K. Hirose, H. Saito, D. Kobayashi, S. Fukuda, S. Ishii, D. Takahashi, K. Yamamoto, and Y. Kuroda, IEEE Transactions on Nuclear Science, 53 (6) pp. 3575-3578 (2006)論文タイトルDirect measurement of SET pulse widths in 0.2-μm SOI logic cells irradiated by heavy ions
-
指導学生名牧野高紘所属大学総合研究大学院大学著者名, ジャーナル名, 巻号ページ（出版年）T. Makino, D. Kobayashi, K. Hirose, Y. Yanagawa, H. Saito, D. Takahashi, S. Ishii, M. Kusano, S. Onoda, T. Hirao, and T. Ohshima, IEEE Transactions on Nuclear Science, 56 (1) pp. 202-207 (2009)論文タイトルLET dependence of single event transient pulse-widths in SOI logic cellDOIhttps://doi.org/10.1109/TNS.2008.2009054
-
指導学生名津川和夫所属大学早稲田大学著者名, ジャーナル名, 巻号ページ（出版年）K. Tsugawa, H. Noda, K. Hirose, and H. Kawarada, Physical Review B, 81 pp. 045303-1-0045303-11 (2010)論文タイトルSchottky barrier heights, carrier density, and negative electron affinity of hydrogen-terminated diamondDOIhttps://doi.org/10.1103/PhysRevB.81.045303
-
指導学生名近田旬佑所属大学早稲田大学著者名, ジャーナル名, 巻号ページ（出版年）S. Chikada, K. Hirose, and T. Yamamoto, Japanese Journal of Applied Physics, 49 pp. 091502-1-091502-3 (2010)論文タイトルAnalysis of local environment of Fe ions in hexagonal BaTiO3DOIhttps://doi.org/133.74.120.63 on 04/02/2021
-
指導学生名金盛治人所属大学早稲田大学著者名, ジャーナル名, 巻号ページ（出版年）H. Kanamori, T. Yoshioka, K. Hirose, and T. Yamamoto, Journal of Electron Spectroscopy and Related Phenomena, 185 pp. 129-132 (2012)論文タイトルDetermination of valence state of Mn ions in Pr1-xAxMnO3-δ (A = Ca, Sr) by Mn-L3 X-ray absorption near-edge structure analysisDOIhttps://doi.org/10.1016/j.elspec.2012.03.003
-
指導学生名元木啓介所属大学早稲田大学著者名, ジャーナル名, 巻号ページ（出版年）K. Motoki, Y. Miyazawa, D. Kobayashi, M. Ikegami, T. Miyasaka, T. Yamamoto, and K. Hirose, Journal of Applied Physics, 121 (8) pp. 085501-1-085501-4 (2017)論文タイトルDegradation of CH3NH3PbI3 perovskite due to soft x-ray irradiation as analyzed by an x-ray photoelectron spectroscopy time-dependent measurement methodDOIhttps://doi.org/10.1063/1.4977238
-
指導学生名井辻宏章所属大学東京大学著者名, ジャーナル名, 巻号ページ（出版年）H. Itsuji, D. Kobayashi, O. Kawasaki, D. Matsuura, T. Narita, M. Kato, S. Ishii, K. Masukawa, and K. Hirose, IEEE Transactions on Nuclear Science, 65 (1) pp. 346-353 (2018)論文タイトルLaser visualization of the development of long line-type multi-cell upsets in back-biased SOI SRAMsDOIhttps://doi.org/10.1109/TNS.2017.2776169
-
指導学生名山口記功所属大学早稲田大学著者名, ジャーナル名, 巻号ページ（出版年）K. Yamaguchi, D. Kobayashi, T. Yamamoto, and K. Hirose, Physica B, 532 pp. 99-102 (2018)論文タイトルTheoretical investigation of the breakdown electric field of SiC polymorphsDOIhttps://doi.org/10.1016/j.physb.2017.03.042
-
指導学生名チョン チンハン所属大学東京大学著者名, ジャーナル名, 巻号ページ（出版年）C-H. Chung, D. Kobayashi, and K. Hirose, IEEE Transactions on Device and Materials Reliability, 18 (4) pp. 574-582 (2018)論文タイトルResistance-based modeling for soft errors in SOI SRAMs caused by radiation-induced potential perturbation under the BOXDOIhttps://doi.org/10.1109/TDMR.2018.2873220
● 専任大学名
2-
専任大学名総合研究大学院大学（SOKENDAI)
-
専任大学名東京大学（University of Tokyo)
● 所属する所内委員会
8-
所内委員会名電子部品デバイス・電源グループ
-
所内委員会名宇宙科学技術・専門統括
-
所内委員会名宇宙科学基盤技術統括
-
所内委員会名宇宙機応用工学研究系
-
所内委員会名運営協議会委員
-
所内委員会名知財委員
-
所内委員会名研究所会議構成員
-
所内委員会名宇宙工学委員会委員
