量研学術機関リポジトリ「QST-Repository」は、国立研究開発法人 量子科学技術研究開発機構に所属する職員等が生み出した学術成果（学会誌発表論文、学会発表、研究開発報告書、特許等）を集積しインターネット上で広く公開するサービスです。 Welcome to QST-Repository where we accumulates and discloses the academic research results(Journal Publications, Conference presentation, Research and Development Report, Patent, etc.) of the members of National Institutes for Quantum Science and Technology.
Thank you very much for using our website. On the 11th of March 2019, this site was moved from our own network server to the JAIRO Cloud network server. If you previously bookmarked this site, that bookmark will no longer work. We would be grateful if you could bookmark the website again. Thank you very much for your understanding and cooperation.
Silicon carbide (SiC) devices are promising as radiation tolerant electronics, since trap generation and charge accumulation by irradiation are suppressed compared with Si devices. However, negative shift of threshold voltage (Vth) of SiC metal-oxide-semiconductor (MOSFET), which is caused by accumulation of holes (positive charges) generated in the gate dielectric (SiO2) by irradiation is a common problem for practical application. SiC junction field effect transistor (JFET), whose gate region is composed of p-n junction is expected to show no negative shift of Vth, while radiation response of SiC JFETs is still unclear. In this study, n-channel depletion mode JFET with nominal channel length and width, and gate length are 2.2 and 0.6, and 18 m (fabricated by AIST ) were irradiated with gamma-rays up to 2.2 MGy at room temperature in nitrogen atmosphere. With increasing dose, Vth gradually shift toward positive voltage side by approximately 1 V. Theoretical expression of JFET suggest that positive shift of Vth is attributed to decrease of carrier density by defects formed in channel region.
Electrical characteristics of gamma-ray irradiated 4H-SiC JFETs
