[15p-315-1~17] 13.8 Compound and power electron devices and process technology

[15p-315-3] Time-dependent dielectric breakdown of atomic-layer-deposition Al₂O₃ films on GaN

〇Atsushi Hiraiwa^1,2, Toshio Sasaki¹, Satoshi Okubo³, Daisuke Matsumura³, Hiroshi Kawarada^1,3,4 (1.RONL, Waseda Univ., 2.IMaSS, Nagoya Univ., 3.FSE, Waseda Univ., 4.KMLMST, Waseda Univ.)

Keywords:Al2O3, dielectric breakdown, GaN

This presentation reports the time-dependent dielectric breakdown characteristics of Al₂O₃ films formed on GaN substrates by using atomic-layer deposition at 450ºC with H₂O oxidant. The distribution of wear-out breakdown lifetimes is narrow enough for practical applications. The 63% lifetime exponentially depends on applied field, and the lifetime under normal operation condition (2 MV/cm) is projected to be 10⁴ years, which are not necessarily long enough for practical applications. To realize high-reliability Al₂O₃ MISFETs, we need to confirm the lifetime degradation at high temperatures and to improve the device fabrication process.