Gamma-ray radiation hardness of Ir contacts in H-terminated diamond MESFETs
Abstract
We investigate the radiation hardness and electrical stability of Ir-based source and drain contacts employed in hydrogen-terminated diamond MESFETs under 100 kGy γ-ray irradiation followed by thermal annealing. The Ir/diamond interface remains electrically stable under the present combined radiation and thermal stress conditions. In contrast, γ-ray exposure induces a positive threshold voltage shift, accompanied by changes in channel conduction consistent with ionization-induced modification of the near-surface electrostatics. A statistical evaluation across multiple devices further shows that the dominant post-irradiation changes are not contact-related, but instead appear in gate-controlled parameters, including a systematic threshold voltage shift and increased variation in subthreshold characteristics after repeated annealing at 200 °C. Taken together, these results identify Ir metallization as a robust source/drain contact strategy for radiation-tolerant diamond electronics and highlight gate-stack engineering as the critical pathway for further reliability improvement.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (7)
Yoonseok Nam
Convergence Center for Advanced Nano Semiconductor, Department of Semiconductor Engineering, Tech University of Korea 1 , Sangidaehak-ro, Siheung-si, Gyeonggi-do 429-793,
Taemyung Kwak
Convergence Center for Advanced Nano Semiconductor, Department of Semiconductor Engineering, Tech University of Korea 1 , Sangidaehak-ro, Siheung-si, Gyeonggi-do 429-793,
Seolyoung Oh
Convergence Center for Advanced Nano Semiconductor, Department of Semiconductor Engineering, Tech University of Korea 1 , Sangidaehak-ro, Siheung-si, Gyeonggi-do 429-793,
Geunho Yoo
Convergence Center for Advanced Nano Semiconductor, Department of Semiconductor Engineering, Tech University of Korea 1 , Sangidaehak-ro, Siheung-si, Gyeonggi-do 429-793,
Dong-Seok Kim
Korea Multi-Purpose Accelerator Complex, Korea Atomic Energy Research Institute (KAERI) 2 , 181 Mirae-ro, Geoncheon-eup, Gyeongju 38180,
Seong-Woo Kim
Orbray Co., Ltd 3 ., 3-8-22 Shinden, Adachi-ku, Tokyo 123-8511,
Okhyun Nam
Convergence Center for Advanced Nano Semiconductor, Department of Semiconductor Engineering, Tech University of Korea 1 , Sangidaehak-ro, Siheung-si, Gyeonggi-do 429-793,