Breakdown voltage in silicon carbide metal-oxide-semiconductor devices induced by ion beams

Oshima, Takeshi; Deki, Manato; Makino, Takahiro; Iwamoto, Naoya; Onoda, Shinobu; Hirao, Toshio*; Kojima, Kazutoshi*; Tomita, Takuro*; Matsuo, Shigeki*; Hashimoto, Shuichi*

AIP Conference Proceedings 1525, p.654 - 658, 2013/04

https://doi.org/10.1063/1.4802408

Metal-Oxide-Semiconductor (MOS) capacitors were fabricated on n-type 4H-SiC epitaxial layers, and the leakage current through the gate oxide during heavy ion irradiation was investigated in order to evaluate dielectric breakdown induced by heavy ions (Single Event Gate Rupture: SEGR). The gate oxide at thickness ranges between 60 and 80 nm was formed using pyrogenic oxidation at 1100 C for 60 min. Circular electrodes with 180 diameter were formed using Al evaporation and a lift-off technique. The leakage current observed through the gate oxide was monitored during 18 MeV oxygen (O) or nickel (Ni) ions. As a result, although no significant difference in the value of the electric field at the dielectric breakdown (around 8.2 MV/cm) was observed between non-irradiated and 18 MeV-O irradiated samples, the value decreased to be 7.3 MV/cm in the case of 18 MeV-Ni ion incidence. The Linier Energy Transfer (LET) for 18 MeV-O is 7 MeV cm/mg, and this value is smaller than that for 18 MeV-Ni (24 MeV cm/mg). Also, 18 MeV-Ni ions deposit energy in narrower regions than 18 MeV-O ions. Thus, it can be concluded that the high density of charge induced by 18 MeV-Ni ions triggers SEGR in SiC MOS capacitors.

Relationship between soft error rate in SOI-SRAM and amount of generated charge by high energy ion probes

Hazama, Masatoshi*; Abo, Satoshi*; Masuda, Naoyuki*; Wakaya, Fujio*; Onoda, Shinobu; Makino, Takahiro; Hirao, Toshio*; Oshima, Takeshi; Iwamatsu, Toshiaki*; Oda, Hidekazu*; et al.

Proceedings of 10th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-10) (Internet), p.115 - 118, 2012/12

-ray irradiated organic thin film transistors based on perfluoropentacene with polyimide gate insulator

Takayanagi, Yutaro*; Ouchi, Hirokuni*; Duan, Z.*; Okukawa, Takanori*; Yanagi, Yuichiro*; Yoshida, Akira*; Taguchi, Mitsumasa; Hirao, Toshio; Nishioka, Yasushiro*

Journal of Photopolymer Science and Technology, 25(4), p.493 - 496, 2012/08

https://doi.org/10.2494/photopolymer.25.493

Organic thin film fields effect transistors are expected to be used in spacecrafts/satellites because they can realize large-size, mechanical flexibility, light weight and low-cost devices. N-channel field effect transistors with a Si/polyimide(PI)/perfluoropentacene/Au structure were fabricated, and irradiated with -ray from Co source. The changes of the drain current vs. source/drain voltage characteristics were measured after every 200 Gy in silicon Gy(Si) irradiations up to the total dose of 1200 Gy(Si). The drain current gradually increased up to the total dose of 1200 Gy(Si). The threshold voltage decreased up to 400 Gy(Si), and gradually recovered above 600 Gy(Si). The mobility was almost unchanged up to 1200 Gy(Si). Those behaviors were explained by accumulation of positive trapped charge within the gate insulator PI near the interface. Evidence for the accumulation of interface traps was hardly observed.

Co-ray irradiation effects on pentacene-based organic thin film transistors

Cai, L.*; Hirao, Toshio; Yano, Hiroaki*; Duan, Z.*; Takayanagi, Yutaro*; Ueki, Hideharu*; Oshima, Takeshi; Nishioka, Yasushiro*

Materials Science Forum, 687, p.576 - 579, 2011/06

https://doi.org/10.4028/www.scientific.net/MSF.687.576

no abstracts in English

DICE-based flip-flop with SET pulse discriminator on a 90 nm bulk CMOS process

Maru, Akifumi*; Shindo, Hiroyuki*; Ebihara, Tsukasa*; Makihara, Akiko*; Hirao, Toshio; Kuboyama, Satoshi*

IEEE Transactions on Nuclear Science, 57(6), p.3602 - 3608, 2010/12

https://doi.org/10.1109/TNS.2010.2086481

no abstracts in English

Characterization of microdose damage caused by single heavy ion observed in trench type power MOSFETs

Ikeda, Naomi*; Kuboyama, Satoshi*; Maru, Akifumi*; Hirao, Toshio; Abe, Hiroshi; Tamura, Takashi*

Proceedings of 9th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-9), p.163 - 166, 2010/10

The trench structure showed an anomalously large degradation by heavy ion irradiation. For the trench structure, ions irradiated normal to the chip surface traverse the gate oxide along the entire length of the channel. Therefore, there is a possibility that the trapped holes resulting from the ion traverse introduce the anomalously large leakage current path. This phenomenon is apparently attributable to the microdose effect. In the previous report, the microdose effect was identified on both trench and planner type of power MOSFETs by real-time measurement of the threshold voltage shift during the heavy ion irradiation with very long range. In this study, detailed characterization of the microdose effects was carried out with several in species. As a result, several damage parameters introduced in the gate oxide by a single ion, such as physical damage size and trapped hole density in the damage region were estimated.

Evaluation of soft errors using nuclear probes in SOI SRAM with body-tie structure fabricated by partial trench isolation

Abo, Satoshi*; Masuda, Naoyuki*; Wakaya, Fujio*; Onoda, Shinobu; Makino, Takahiro; Hirao, Toshio; Oshima, Takeshi; Iwamatsu, Toshiaki*; Oda, Hidekazu*; Takai, Mikio*

Proceedings of 9th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-9), p.72 - 75, 2010/10

no abstracts in English

Electrical characteristics of Co -ray irradiated pentacene-based organic thin film field effect transistors

Cai, L.*; Hirao, Toshio; Yano, Hiroaki*; Duan, Z.*; Takayanagi, Hideharu*; Ueki, Hideharu*; Oshima, Takeshi; Nishioka, Yasushiro*

Proceedings of 9th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-9), p.176 - 178, 2010/10

no abstracts in English

Current transient effect in N-channel 6H-SiC MOSFET induced by heavy ion irradiation

Lee, K. K.*; Laird, J. S.*; Oshima, Takeshi; Onoda, Shinobu; Hirao, Toshio; Ito, Hisayoshi

Materials Science Forum, 645-648, p.1013 - 1016, 2010/04

no abstracts in English

Verification of soft-error rate estimation method in a logic LSI

Makino, Takahiro; Onoda, Shinobu; Hirao, Toshio; Oshima, Takeshi; Kobayashi, Daisuke*; Hirose, Kazuyuki*

Proceedings of the 28th Symposium on Materials Science and Engineering, Research Center of Ion Beam Technology Hosei University, p.35 - 40, 2009/12

We want to reveal the relation between SET-induced soft-error rates (s) and SET pulse-width distribution to be able to reduce the with an SET filter like an RC filter or a temporal latch architecture. By considering the relation between and SET pulse-width, we can determine the minimum time constant for the SET filter to reduce the effectively. A theoretical estimation has been proposed to obtain in a logic LSI from SET pulse-widths measured in logic cells and the latch probability of SET pulses at flip-flops (FFs) used in logic LSIs. However, the estimation method has not been verified yet. In this paper, we verify the theoretical estimation method.