A5001749718- Silicon Carbide Semiconductor Technologies
- Semiconductor materials and devices
- Semiconductor materials and interfaces
- Silicon and Solar Cell Technologies
- Copper Interconnects and Reliability
- Thin-Film Transistor Technologies
- Electromagnetic Compatibility and Noise Suppression
- Integrated Circuits and Semiconductor Failure Analysis
- Advanced ceramic materials synthesis
- Advanced Surface Polishing Techniques
- Electrostatic Discharge in Electronics
- Induction Heating and Inverter Technology
- Multilevel Inverters and Converters
- Aluminum Alloys Composites Properties
- Silicon Nanostructures and Photoluminescence
- Diamond and Carbon-based Materials Research
- Pulsed Power Technology Applications
- Advanced DC-DC Converters
- GaN-based semiconductor devices and materials
- Aluminum Alloy Microstructure Properties
- HVDC Systems and Fault Protection
- Ion-surface interactions and analysis
- Advancements in Semiconductor Devices and Circuit Design
- Metal and Thin Film Mechanics
- Solidification and crystal growth phenomena
Central Research Institute of Electric Power Industry
2016-2025
National Institute of Advanced Industrial Science and Technology
2016-2021
National Institutes for Quantum Science and Technology
2021
Gwangju Institute of Science and Technology
2021
Saitama University
2021
Fuji Electric (Japan)
2016-2019
Kyoto Katsura Hospital
2017-2018
Kyoto University
2016-2018
Nitto (Japan)
2018
Showa Denko (Japan)
2017
The authors report a significant reduction in deep level defects and improvement of carrier lifetime 4H-SiC material after carrying out carbon or silicon ion implantation into the shallow surface layer 250nm subsequent annealing at 1600°C higher temperature. Reduction Z1∕2 EH6∕7 traps from 3×1013cm−3 to below detection limit (5×1011cm−3) was observed by transient spectroscopy 4μm underneath implanted layer. Minority almost doubled samples compared unimplanted samples. propose that acts as...
Abstract This paper surveys extended defects in 4H‐SiC epilayers and reports recent results concerning fast epitaxial growth. Synchrotron X‐ray topography, transmission electron microscopy, Nomarski optical microscopy defect selective etching analysis are applied to investigate the nucleation propagation of carrot defects, basal plane Frank‐type polytype inclusions dislocations (BPDs) In development growth technique, a very high rate up 250 μm/h is obtained newly developed vertical...
We investigated the dependency of minority carrier lifetimes on nitrogen concentration, temperature, and injected concentration for highly nitrogen-doped 4H-SiC epilayers. The greatly shortened when exceeded 1018 cm−3 through enhancing direct band-to-band Auger recombination showed a slight variation in temperature range from room (RT) to 250 °C. epilayer with 9.3 × exhibited very short lifetime 38 ns at RT 43 were confirmed maintain values even after subsequent annealing 1700 PiN diodes...
The growth of Shockley type stacking faults in p-i-n diodes fabricated on the C-face 4H-SiC during forward current operation was investigated using Berg-Barrett X-ray topography and photoluminescence imaging. After experiment, were generated from very short portions basal plane dislocations lower than conversion points to threading edge epitaxial layer. behavior discussed. Growth substrates not observed.
The authors investigated the application of carbon-implantation/annealing method for annealing main lifetime limiting defect Z1∕2 in thick 4H–SiC epilayers. Examination different implantation doses and temperatures showed that finding optimum conditions is crucial obtaining layers with carrier trap concentration below 1011cm−3 whole 100μm epilayer. increased from less than 200ns to over 1μs at room temperature samples annealed carbon-implanted layer. epilayers after were confirmed be...
We investigated the structure of in-grown stacking faults in 4H–SiC(0001) epilayers. The nucleate near substrate/epilayer interface and expand area with increasing epilayer thickness a triangular shape. From transmission electron microscope observation, formation 1c 8H polytype was confirmed fault area. also dependence density on epitaxial growth rate, temperature, substrate surface preparation.
A vertical hot-wall epi-reactor that makes it possible to simultaneously achieve a high growth rate and large-area uniformity has been developed. maximum of 250 µm/h is achieved with mirror-like morphology at 1650 °C. Under modified setup, thickness 1.1% doping 6.7% for 65-mm-radius area are while maintaining 79 µm/h. low concentration ∼1×1013 cm-3 obtained 50-mm-radius area. The low-temperature photoluminescence (LTPL) spectrum shows the predominance free exciton peaks only few...
The carrier lifetime of ∼265 μm thick n-type 4H silicon carbide epilayers prepared using the carbon-implantation/annealing method was evaluated. An extraordinarily long minority 18.5 μs and a high injection 19.2 were evaluated from time-resolved photoluminescence microwave photoconductivity decay measurements, respectively. Based on relationship between epilayer thickness lifetime, influence surface recombination eliminated, bulk hole diffusion constant discussed.
Frank-type defects on the basal plane in thick 4H–SiC epitaxial layers have been characterized by photoluminescence (PL) spectroscopy and a PL imaging microscopy. The emission wavelength of three kinds were determined at ∼424, 457, 488 nm room temperature, respectively. high-resolution was obtained, Frank partial dislocations confirmed near infrared region (>700 nm). Correspondence between optical properties microscopic structures clarified.
Impacts of extended defects on performance and reliability SiC power devices are reviewed. Threading dislocations in the state-of-the-art wafers do not work as major leakage paths macroscopic generated during epitaxial process more harmful. A basal plane dislocation is a killing defect bipolar because Shockley-type stacking fault (SSF) expanded from when electron-hole recombination energy given. After classification SSF-expansion patterns, types SSFs (triangular-shaped bar-shaped SSFs) their...
We investigated the relationship between dislocation velocity and injected carrier concentration on expansion of single Shockley-type stacking faults by monitoring electroluminescence from 4H-SiC PiN diodes with various anode Al concentrations. The was calculated using a device simulation that took into account measured accumulated charge in drift layer during diode turn-off. strongly dependent hole concentration, which represents excess concentration. activation energy quite small (below...
We investigated the annealing effect on single Shockley faults (SSFs) in SiC epitaxial layers by photoluminescence mapping combination with high-power laser illumination. Comparing before and after at 350–550°C, it became obvious that results shrinking of faulted area SSFs. When illumination is performed again same annealed 550°C, right-angled triangular SSFs reformed into exactly features as those annealing, but isosceles did not reform. The temperature to start differs according type SSF.
Abstract Establishing a robust and integratable quantum system capable of sensitive qubit readout at ambient conditions is key challenge for developing prevalent technologies, including networks sensing. Paramagnetic colour centres in wide bandgap semiconductors provide optical single-spin detection, yet realising efficient electrical technology scalable material will unchain integrated electronics. Here, we demonstrate photoelectrical detection single spins silicon carbide, amenable to...
In this paper, we studied the structural transformation of screw dislocations through gas-phase 4H-SiC epitaxial growth. We confirmed based on numbers and features etch pits a surface after KOH treatment that some micropipes were closed in layer, divided into several elementary dislocations. discuss magnitude Burgers vectors substrates relation to number generated by micropipe closing. A depth analysis further revealed most closings took place initial stage
The formation of extended defects in the 4H–SiC epilayer induced by implantation/annealing process was investigated using synchrotron reflection x-ray topography, KOH etching analysis, and transmission electron microscopy. High temperature annealing performed for with or without implantation nitrogen aluminum ions. Other than platelet extrinsic Frank-type faults implanted region as reported previously, we find modes following three categories: (i) dislocation near epilayer/substrate...
The impact of two post-growth processes, namely, C+-implantation/annealing process and thermal oxidation/annealing process, on trap concentrations in thick n-type 4H-SiC epilayers was studied for both Si- C-face. Conditions such as the implantation dose annealing temperature processes were optimized Si-face epilayers, consequently Z1/2 center eliminated up to 100 μm or more, minority carrier lifetime reached 13 μs while maintaining a good surface morphology. effect conditions creation new...
Conversion of basal plane dislocations (BPDs) to threading edge (TEDs) is found in 4H-SiC epilayers after being annealed simply at high temperatures. Grazing incidence reflection synchrotron x-ray topography for the before and annealing confirmed that some BPDs had converted TEDs from epilayer surface by annealing. Observations on dislocation behavior during are explained detail, mechanism BPD conversion discussed. It argued proceeds through cross slip constricted segments towards prismatic...
Shockley-type stacking faults expanded in 4H–SiC epilayers induced by ultraviolet illumination were investigated using a photoluminescence imaging method, mapping method and X-ray topography. After illumination, more than 30 patterns of which from perfect basal plane dislocations observed imaging. The initial crystallographically classified, individual shapes predicted. correspondence between the predicted ones was discussed.