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Onoda, Shinobu; Iwamoto, Naoya; Murakami, Makoto; Oshima, Takeshi; Hirao, Toshio; Kojima, Kazutoshi*; Kawano, Katsuyasu*; Nakano, Itsuo*
Materials Science Forum, 615-617, p.861 - 864, 2009/00
no abstracts in English
Oshima, Takeshi; Onoda, Shinobu; Kamada, Toru*; Hotta, Kazutoshi*; Kawata, Kenji*; Eryu, Osamu*
Materials Science Forum, 615-617, p.781 - 784, 2009/00
Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) were fabricated on p-type epitaxial 4H-SiC substrates with different surface conditions. These electrical characteristics were compared from a point of view of the surface condition. The MOSFETs on Chemical Mechanical Polished substrates showed the drain current of the order of 10
A at a gate voltage of zero. The drain current increased with increasing the surface roughness of substrates. With decreasing the surface roughness of substrates, the values of the threshold voltage decreased and the quality of gate oxide became better.
Iwamoto, Naoya; Onoda, Shinobu; Oshima, Takeshi; Kojima, Kazutoshi*; Kawano, Katsuyasu*
Materials Science Forum, 615-617, p.517 - 520, 2009/00
Single event transient currents induced in 6H-SiC Metal-Oxide-Semiconductors (MOS) capacitors by using oxygen ions are investigated. Charges collected from the MOS capacitors are estimated by the integration of transient currents. Applying the drift-diffusion model to the collected charges, the diffusion length of electron is estimated. Transient currents induced in the 
-ray irradiated MOS capacitors are also investigated. No significant change in the transient currents is observed after -ray irradiation.
Son, N. T.*; Isoya, Junichi*; Morishita, Norio; Oshima, Takeshi; Ito, Hisayoshi; Gali, A.*; Janz
n, E.*
Materials Science Forum, 615-617, p.377 - 380, 2009/00
Defects introduced by electron irradiation at 
80-100 K in 3C-, 4H- and 6H-Silicon Carbide (SiC) were investigated by Electron Paramagnetic Resonance (EPR). A number of EPR spectra, labelled LE1-10, were detected. Combining EPR and theoretical calculations (supercell calculation), the LE1 center in 3C-SiC with C
symmetry and an electron spin S=3/2 could be determined to be the (V
-Si
)
Frenkel pair between the silicon vacancy and a second neighbor Si interstitial along the 
100 
direction.
Gali, A.*; Umeda, Takahide*; Janzn, E.*; Morishita, Norio; Oshima, Takeshi; Isoya, Junichi*
Materials Science Forum, 615-617, p.361 - 364, 2009/00
Carbon antisite defects in Silicon Carbide (SiC) were studied using Electron Spin Resonance (ESR) and first principle calculations. The samples used in this study were n-type 4H-SiC, and these samples were irradiated with MeV electrons at 10
/cm
in temperature range between 300 and 800
C. As the results of ESR measurements, signals labeled HEI5 and HEI6, which have S=1/2 and C
symmetry were observed. By the detailed measurements of 
Si and 
C hyperfine satellite, and first principle calculations, HEI5 and HEI6 were identified to be di-carbon antisite at cubic and hexagonal sites, respectively.
center in 4
-SiCIsoya, Junichi*; Umeda, Takahide*; Mizuochi, Norikazu*; Oshima, Takeshi
Materials Science Forum, 615-617, p.353 - 356, 2009/00
To indentify intrinsic defects in silicon carbide (SiC), a T center in 4-SiC was investigated using pulsed electron paramagnetic resonance (EPR). The T is a center with S=3/2 and C
symmetry, and in previous studies, the origin of the T is thought to be a defects of negatively charged Si vacancy (V
). In this study, T centers were introduced in n-type 4-SiC samples by MeV range electron irradiation at 10 /cm. As a result of EPR, pulsed EPR and ENDOR measurements, the origin of the Tcenter can be identified to be not a simple V defect but the complex between V with Next Nearest Neighbors.