[18p-F206-1~15] 6.2 Carbon-based thin films

[18p-F206-3] Edge termination technique for high-voltage diamond p-i-n diodes

〇(P)Aboulaye Traore¹, Toshiharu Makino^1,2, Akira Nakajima¹, Hiromitsu Kato¹, Masahiko Ogura¹, Yukako Kato¹, Satoshi Yamasaki^1,2 (1.AIST, 2.Univ. Of Tsukuba)

Keywords:Diamond, p-i-n diode, Edge termination

Nowadays, bipolar diamond devices such as p-i-n diodes are being intensively investigated for ultra-high voltage operations. Thanks to their key features, namely, the conductivity modulation, bipolar diamond devices are expected to outperform unipolar devices such as Schottky diodes in term of lower conduction resistance. Among diamond bipolar devices, p-i-n diodes are today the most advanced and promising. Over the last few decades, basic diamond p-i-n diodes have shown promising electrical properties such as a maximum breakdown field of 2.3 and 5.1 MV/cm. Unfortunately, the reported breakdown field are still low compared to theoretical diamond limit (>10 MV/cm). The voltage blocking capabilities of diamond p-i-n diodes are today mainly limited by their basic design without edge termination. To achieve a breakdown field close to the diamond limit, efficient edge termination technologies are needed to supress electrical field crowding in edge regions.
In this work, pioneer studies on design and fabrication of edge termination for high voltage diamond p-i-n diodes are introduced. Multi-step junction termination extension (MJTE) technology has been developed to enhance the blocking capabilities of diamond p-i-n diodes and to achieve a breakdown field close to the diamond limit. The effectiveness of developed MJTE technology has been numerically and experimentally demonstrated.