Development of diagnostic method for deep levels in semiconductors using charge induced by heavy ion microbeams

Kada, Wataru*; Kambayashi, Yuya*; Iwamoto, Naoya*; Onoda, Shinobu; Makino, Takahiro; Koka, Masashi; Kamiya, Tomihiro; Hoshino, Norihiro*; Tsuchida, Hidekazu*; Kojima, Kazutoshi*; et al.

Nuclear Instruments and Methods in Physics Research B, 348, p.240 - 245, 2015/04

https://doi.org/10.1016/j.nimb.2014.12.054

Heavy-ion induced anomalous charge collection from 4H-SiC Schottky barrier diodes

Makino, Takahiro; Deki, Manato; Iwamoto, Naoya; Onoda, Shinobu; Hoshino, Norihiro*; Tsuchida, Hidekazu*; Hirao, Toshio*; Oshima, Takeshi

IEEE Transactions on Nuclear Science, 60(4), p.2647 - 2650, 2013/08

https://doi.org/10.1109/TNS.2013.2243469

Heavy ion induced anomalous charge collection was observed from 4H-SiC Schottky barrier diodes. It is suggested that the incident ion range with suspect to the thickness of the epi-layer of the SBD in key to understanding these observation and the understanding mechanism.

Heavy-ion-induced charge enhancement in 4H-SiC schottky barrier diodes

Makino, Takahiro; Deki, Manato; Iwamoto, Naoya; Onoda, Shinobu; Hoshino, Norihiro*; Tsuchida, Hidekazu*; Oshima, Takeshi

Proceedings of 10th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-10) (Internet), p.66 - 69, 2012/12

Silicon carbide (SiC) is regarded as a promising candidate for electronic devices requiring high radiation tolerance (rad-hard devices). Some results indicate that SiC has superior radiation tolerance from the point of view of total ionizing dose effects (TIDs). For the development of rad-hard SiC devices, it is necessary to understand the response of their performance when dense charge is generated in them by an incident ion, resulting in single event effects (SEEs). Therefore, we have measured the bias dependence of the collected charge distribution induced by heavy ions in 4H-SiC-schottky barrier diodes (SBDs) fabricated in thick epi-layer to reveal SEE mechanisms. As a result, anomalous collected charge peaks (2nd peaks) induced by the heavy ions were observed for the first time. The new process of the SEB was observed in the case of incident ions on thick epi-layer of SiC-SBDs.

Simulation for SiC power electronic device developments

Onuma, Toshiharu*; Miyashita, Atsumi; Yoshikawa, Masahito; Tsuchida, Hidekazu*; Iwasawa, Misako*

Heisei-21-Nendo Sentan Kenkyu Shisetsu Kyoyo Sokushin Jigyo "Chikyu Shimyureta Sangyo Senryaku Riyo Puroguramu" Riyo Seika Hokokusho, p.21 - 27, 2010/07

http://www.jamstec.go.jp/es/jp/project/sangyou_report/H21_report.html

Silicon carbide, being a wide-band-gap semiconductor, is an attractive material in the development of electronic devices operated under extreme conditions such as high power, high temperature, and high radiation. SiC is particularly attractive for use in MOS technology because among the compound semiconductors only silicon carbide has the thermal oxide SiO, which is a good insulator. However, it is known that SiO/SiC interfaces have a higher density of interface traps than SiO/Si interfaces and that the channel mobility of MOS devices is much lower than theoretically expected values. In order to improve these characteristics, it is important to understand the thermal oxidation process at the SiO/SiC interface. We performed large-scale first-principles molecular dynamics simulations of the SiO/SiC interface oxidation process. We also performed large-scale first-principles molecular dynamics simulations to generate amorphous SiO/SiC interface.

Generation of amorphous SiO/SiC interface structure by the first-principles molecular dynamics simulation

Miyashita, Atsumi; Onuma, Toshiharu*; Iwasawa, Misako*; Tsuchida, Hidekazu*; Yoshikawa, Masahito

Materials Science Forum, 556-557, p.521 - 524, 2007/00

SiC semiconductor devices are expected to be used in severe environments. However, SiC devices don't present the theoretically expected performance. This is considered to be attributed to the SiO/SiC interface defects that reduce electrical characteristics of devices. To generate the real device interface structure with the computer simulation, it is important to construct the a-SiO structure on SiC. The slab model using 444 atoms for a-SiO on a 4H-SiC (0001) crystal layer was constructed by using first-principles MD simulation. The heating and rapid quenching method was carried out to make an a-SiO/SiC interface structure. The heating temperature, the heating time and the speed of rapid quenching is 4000 K, 3.0 ps and -1000 K/ps, respectively. The interatomic distance and the bond angles of SiO layers agreed well with the most probable values in bulk a-SiO, and there were no coordination defects in the neighborhood of the SiC substrate.

Electrical characteristics of interface defects in oxides grown at 1200 C in dry oxygen ambient on silicon carbide and their thermal annealing effects

Yoshikawa, Masahito; Ishida, Yuki*; Jikimoto, Tamotsu*; Hijikata, Yasuto*; Ito, Hisayoshi; Okumura, Hajime*; Takahashi, Tetsuo*; Tsuchida, Hidekazu*; Yoshida, Sadafumi*

Denshi Joho Tsushin Gakkai Rombunshi, C, 86(4), p.426 - 433, 2003/04

https://ci.nii.ac.jp/naid/110003172129

no abstracts in English

Generation of amorphous interface by the first-principles molecular dynamics simulation

Miyashita, Atsumi; Onuma, Toshiharu*; Yoshikawa, Masahito; Iwasawa, Misako*; Nakamura, Tomonori*; Tsuchida, Hidekazu*

no journal, , 

Silicon carbide (SiC) semiconductor devices are expected to be used under severe environments such as outer space and/or nuclear power plants. However, at this time, SiC devices don't present the predictable performance, since defects at interface reduce electric characteristics of them. The relation among atomic structures, interfacial defects and electric characteristics is not clear. Therefore, we tried to solve these problems by the computer simulation. The SiO/SiC interface structure is generated and the electronic geometry is decided by the first-principle molecular dynamics (MD) simulation with the Earth-Simulator. The amorphous interface structure is made by heating and rapid quench calculation using 444 atoms model. The heating temperature is 4000K, the heating time is 3.0ps, and the speed of rapid quench is . After a rapid quench, the atomic structure became an almost perfect interfacial structure. However, a few defect energy levels were still observed in the band gap. The defect energy levels are originated from the localized electronic distribution of the interfacial oxygen.

Generation of amorphous SiO/SiC interface structure by the first-principles

Miyashita, Atsumi; Onuma, Toshiharu*; Iwasawa, Misako*; Yoshikawa, Masahito; Tsuchida, Hidekazu*

no journal, , 

no abstracts in English

Generation of amorphous SiO/SiC interface by the simulation; First-principles molecular dynamics

Miyashita, Atsumi; Onuma, Toshiharu*; Iwasawa, Misako*; Tsuchida, Hidekazu*; Yoshikawa, Masahito

no journal, , 

no abstracts in English

Generation of amorphous SiO/SiC interface structure by the first-principles, 2

Miyashita, Atsumi; Onuma, Toshiharu*; Iwasawa, Misako*; Tsuchida, Hidekazu*; Yoshikawa, Masahito

no journal, , 

no abstracts in English