A5018925721- Silicon Carbide Semiconductor Technologies
- Semiconductor materials and devices
- Advancements in Semiconductor Devices and Circuit Design
- Copper Interconnects and Reliability
- Electromagnetic Compatibility and Noise Suppression
- GaN-based semiconductor devices and materials
- Photonic and Optical Devices
- Semiconductor Lasers and Optical Devices
- Semiconductor materials and interfaces
- Multilevel Inverters and Converters
- Thin-Film Transistor Technologies
- Integrated Circuits and Semiconductor Failure Analysis
- Optical Network Technologies
- Silicon and Solar Cell Technologies
- Metal and Thin Film Mechanics
- Plasma Diagnostics and Applications
- Advanced Photonic Communication Systems
- Diamond and Carbon-based Materials Research
- Semiconductor Quantum Structures and Devices
- Silicon Nanostructures and Photoluminescence
- Advanced ceramic materials synthesis
- Advanced DC-DC Converters
- Advancements in Photolithography Techniques
- Acoustic Wave Resonator Technologies
- ZnO doping and properties
National Institute of Advanced Industrial Science and Technology
2015-2024
Toyama Prefectural University
2022
Advanced Power Electronics (United States)
2014-2017
Advance (Japan)
2017
National Institute Of Technology, Ishikawa College
2017
Fujitsu (Japan)
2002-2014
Nara Institute of Science and Technology
2008
NTT (Japan)
1992-2005
Tokyo Institute of Technology
2003-2004
NEC (Japan)
2002-2003
Ultrahigh-voltage silicon carbide (SiC) devices [p-i-n diodes and insulated-gate bipolar transistors (IGBTs)] switching test have been investigated. As a result, we succeeded in developing 13-kV p-i-n diode, 15-kV p-channel IGBT, 16-kV flip-type n-channel implantation epitaxial IGBT with low differential specific on-resistance ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> <inline-formula xmlns:xlink="http://www.w3.org/1999/xlink">...
A 1.3 µm laser has been developed with a butt-jointed selectively grown spot-size converter (SSC). The SSC, vertically tapered waveguide and strained multiquantum well (MQW) active region are independently optimised. was buried semi-insulating InP to reduce optical loss in the SSC. threshold current of 7 mA an output power > 20 mW were obtained. Minimum coupling flat-end fibre 1.06 dB achieved. Long-term stability also confirmed.
In this study, we have realized a monolithic silicon carbide (SiC) power integrated circuit (IC) integrating 1.2 kV-class trench gate vertical metal-oxide-semiconductor field-effect transistor (MOSFET) and complementary (CMOS) buffer aiming to enhance the fast switching by eliminating parasitic effects caused external interconnections. The p-MOSFETs in SiC CMOS were balanced with n-MOSFETs using an epitaxial buried channel structure. allowed control MOSFET successfully. A breakdown voltage...
We fabricated and characterized an ultrahigh voltage (>10kV) p-channel silicon carbide insulated gate bipolar transistor (SiC-IGBT) with high channel mobility. Higher field-effect mobility of 13.5 cm 2 /Vs was achieved by the combination adopting n-type base layer a retrograde doping profile additional wet re-oxidation annealing (wet-ROA) at 1100°C in oxidation process. The on-state characteristics SiC-IGBT 200°C showed low differential specific on-resistance 24 mΩcm V G = -20 V. forward...
High temperature operation is demonstrated for narrow-beam 1.3 µm lasers with butt-jointed selectively grown spot-size converters. Low thresholds of 5.6 mA and 15.8 at 25°C 85°C a maximum operating 134°C were obtained. loss coupling to fibre <1.8 dB was achieved in the range from an output power up 30 mW.
This letter provides the first report of 160-Gb/s optical time-division-multiplexed transmission with all-channel independent modulation and simultaneous demultiplexing. By using a multiplexer demultiplexer based on periodically poled lithium niobate semiconductor amplifier hybrid integrated planar lightwave circuits, 160-km is successfully demonstrated.
We fabricated inversion-type 4H–SiC p-channel metal-oxide-semiconductor field-effect transistors (MOSFETs). The electrical properties of the MOSFETs depended on gate oxidation process. found that wet process was effective for improving channel mobility MOSFET, and obtained μFE 15.6cm2∕Vs by using Measurements p-type MOS capacitors implied SiO2∕SiC interface states around valence band affected threshold voltage MOSFETs. also investigated temperature dependences.
The instability in the electrical properties of 4H-SiC(0001) C-face metal–oxide–semiconductor (MOS) systems processed by wet gate oxidation with H2 postoxidation annealing (POA) was characterized. Wet-oxidized 4H-SiC MOS capacitors indicated a large flat-band voltage (Vfb) shift owing to gate-bias stressing, but POA process improved Vfb significantly. threshold (Vth) wet-oxidized field-effect transistors reduced greatly one-tenth using an appropriate process. These samples also high channel...
We present single photon sources (SPSs) embedded in 4H-SiC metal-oxide-semiconductor field-effect transistors (MOSFETs). They are formed the SiC/SiO2 interface regions of wet-oxidation C-face MOSFETs and were not found other Si-face MOSFETs. Their bright room-temperature photoluminescence (PL) was observed range from 550 to 750 nm revealed variable multi-peak structures as well peak shifts. characterized a wide variety their PL spectra inevitable variation local atomic at interface....
The Letter describes InGaAsP/InP 1.55 μm distributed Bragg reflector lasers monolithically integrated with a laterally tapered waveguide on the output facet. region of devices has thick partially clad p-InP layer grown by selective growth. growth and fabrication processing steps were same as those used to make conventional DBR laser diodes. demonstrate good lasing characteristics, lowloss coupling less than 2.8 dB +/− 2 misalignment tolerance flat-end singlemode fibre in both lateral...
The inversion channel mobility of 4H and 6H-SiC(0001) metal-oxide-semiconductor field-effect transistors (MOSFETs) has been evaluated for its dependence on the re-oxidation annealing (ROA) conditions in a wet oxidizing ambient. ambient was supplied by pyrogenic reaction hydrogen oxygen gas (pyrogenic ROA), where water vapor content (/spl rho/(H/sub 2/O)) controlled adjusting hydrogen/oxygen flow rate. Not only temperature time, but also /spl 2/O) are found to be critical parameters improving...
Ultralow on-resistance silicon carbide static induction transistors with buried gate structures (SiC-BGSITs) have been successfully developed through innovative fabrication process. A submicrometer p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> structure was fabricated by the combination of trench dry etching and epitaxial growth on a structure. The breakdown voltage V <sub xmlns:xlink="http://www.w3.org/1999/xlink">BR</sub> specific...
Anomalous charge-pumping characteristics of 4H-silicon carbide (SiC) MOSFETs were analyzed. Charge-pumping measurements n- and p-channel 4H-SiC with without NO annealing performed. Measurements using various pulse fall times revealed that the geometric component exists in n-channel is particularly large unannealed low channel mobility. In addition, influence interface states on curves significant MOSFETs. The are distorted by these two nonideal effects, making analysis difficult. A...
Flip-type n-channel implantation and epitaxial (IE)-IGBT on 4H-SiC carbon face with an p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">++</sup> collector layer was investigated. In this study, we employed the IEMOSFET as a MOSFET structure original wet gate oxidation method, to realize high channel mobility. We were able achieve ultrahigh blocking voltage of more than 16 kV, extremely low forward drop 5 V at 100 A/cm...
The K computer, released on September 29, 2012, is a large-scale parallel supercomputer system consisting of 82,944 compute nodes. We have been able to resolve significant number operation issues since its release. Some software components fixed and improved obtain higher stability utilization. achieved 94% service availability because low hardware failure rate approximately 80% node utilization by careful adjustment parameters. found that the computer an extremely stable high system.
Ultrahigh-voltage SiC flip-type n-channel implantation and epitaxial (IE)-IGBTs were developed, the static dynamic performance was investigated. A large device (8 mm × 8mm) with a blocking voltage greater than 16 kV achieved, an on-state current of 20 obtained at low (V on ) 4.8 V. R diff 23 mΩ·cm 2 V = In order to evaluate switching characteristics IE-IGBT, ultrahigh-voltage power modules assembled. chopper circuit configuration used IE-IGBT. Smooth turn-off waveforms successfully CE 6.5 I...
We investigated a metal-oxide-semiconductor interface of dry-oxidized (0001¯) 4H-SiC, which was known as the most electrically deteriorated SiC MOSFET, by detected magnetic resonance (EDMR) and observed signal with an isotropic g factor (2.0024) magnetic-field angular dependent widths. Judging from factor, comes sp2-bonded carbon clusters. In addition, we found that dependence EDMR widths caused two-dimensional dipolar broadening exchange interaction between electron spins. However, density...
160 Gbit/s full time-division demultiplexing using a semiconductor optical amplifier hybrid integrated demultiplexer on planar lightwave circuit is demonstrated. Error-free, from signal to eight-channel, 20 signals successfully
The most important issue in realizing a 4H-SiC vertical MOSFET is to improve the poor channel mobility at MOS interface, which related high on-resistance. This letter focuses on novel device structure where low acceptor concentration epitaxial layer used as channel. We call this double-epitaxial (DEMOSFET). In structure, p-well composed of two p-type layers, while an n-type region between p-wells formed by low-dose ion implantation. A buried surface upper p/sup $/epitaxial layer. fabricated...
4H-SiC carbon face flip-type n-channel implantation and epitaxial (IE)-IGBT with an p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">++</sup> substrate was developed its switching test carried out. We were able to achieve ultrahigh blocking voltage greater than 16 kV, extremely low V <inf xmlns:xlink="http://www.w3.org/1999/xlink">on</inf> (6.35 at 20 A), good temperature stability. The operation achieved by connecting three IGBTs in parallel,...
4H-SiC(000-1) C-face was oxidized in H 2 O and mixture gas (H rich wet ambient) for the first time. ambient formed by catalytic water vapor generator (WVG) system, where action instantaneously enhances reactivity between to produce O. The dependence of SiC oxidation rate on partial pressure investigated. We fabricated 4H-SiC MOS capacitor MOSFET re-oxidation following dry oxidation. density interface traps reduced channel mobility improved comparison with conventional
Although the channel resistance is partially reduced by suppressing 4H–SiC/SiO2 interface trapping, scattering still presents a problem. To clearly extract effective-field (Eeff) dependence of dominant scattering, body biasing technique was adopted, under condition that charge density constant to fix screening effect. The electron mobilities were observed be several fold higher for a-, m-, and 03¯38¯ faces than Si- C-faces. This result primarily due magnitude difference in Eeff-dependent...
Abstract Nitridation of SiO 2 /4H-SiC(112̄0) interfaces with post-oxidation annealing in an NO ambient (NO-POA) and its impact on the electrical properties were investigated. Sub-nm-resolution nitrogen depth profiling at was conducted by using a scanning X-ray photoelectron spectroscopy microprobe. The results showed that atoms incorporated just interface nitridation proceeded much faster than /SiC(0001) interfaces, resulting 2.3 times higher concentration. Electrical characterizations...