[10p-Z04-1~17] 13.7 Compound and power electron devices and process technology

[10p-Z04-8] Current conduction in ALD-Al₂O₃/GaN capacitors formed by post-deposition annealing

〇Atsushi Hiraiwa^1,4, Kiyotaka Horikawa², Satoshi Okubo², Hiroshi Kawarada^1,2,3 (1.RONLI, Waseda Univ., 2.FSE, Waseda Univ., 3.KMLMST, Waseda Univ., 4.IMaSS, Nagoya Univ.)

Keywords:Al2O3, annealing, crystallinity

The conduction current in atomic-layer-deposited Al₂O₃/GaN capacitors was markedly reduced by post-deposition annealing at crystallizing temperatures. A space-charge-controlled field emission analysis revealed that the current reduction was achieved by the increase in the energy barrier at the Al₂O₃/GaN interface. By analyzing the selected area electron diffraction patterns from the cross section of the capacitors, the crystallized Al₂O₃ was found to be γ-Al₂O₃ with 111 preferential orientation in an epitaxial relation with the (0001) GaN substrate where the orientation <01-1> of γ-Al₂O₃ is parallel with the orientation <2-1-10> of GaN.