2021/11/19 更新

写真a

オカ トオル
岡 徹
OKA Toru
所属
未来材料・システム研究所 豊田合成GaN先端デバイス応用産学協同研究部門 特任教授
職名
特任教授

学位 1

  1. 博士(工学) ( 2003年3月   京都大学 ) 

 

論文 1

  1. Increase of reverse leakage current at homoepitaxial GaN p-n junctions induced by continuous forward current stress

    Narita Tetsuo, Nagasato Yoshitaka, Kanechika Masakazu, Kondo Takeshi, Uesugi Tsutomu, Tomita Kazuyoshi, Ikeda Satoshi, Yamaguchi Satoshi, Kimoto Yasuji, Kosaki Masayoshi, Oka Tohru, Kojima Jun, Suda Jun

    APPLIED PHYSICS LETTERS   118 巻 ( 25 )   2021年6月

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    記述言語:日本語   出版者・発行元:Applied Physics Letters  

    Reliability tests involving the application of high electrical stresses were employed to assess GaN-based vertical p-n junctions fabricated on freestanding GaN substrates with threading dislocation densities less than 104 cm−2. Electric field crowding at the device edges was eliminated by employing a shallow bevel mesa structure, thus allowing an evaluation of the reliability of the internal p-n junctions. The p-n diodes exhibited reproducible avalanche breakdown characteristics over the temperature range of 25-175 °C. No degradation was observed even during tests in which the devices were held under a reverse bias near the breakdown voltage. Despite this high degree of reliability in response to reverse bias stress, a small number of diodes were degraded during continuous forward current tests, although the majority of diodes remained unchanged. The reverse leakage current exhibited by degraded diodes was increased with an increase in the forward current density within the range of 50-500 A/cm2, while the breakdown voltages were unchanged in response to current stress. The leakage level increased exponentially with an increase in the total amount of injected carriers but eventually plateaued. In the degraded p-n diode, a luminous point in an emission microscope corresponded to one of the threading dislocations observed in the synchrotron x-ray topography, indicating that a specific dislocation played as a leakage path after injecting carriers.

    DOI: 10.1063/5.0053139

    Web of Science

    Scopus