[14a-B401-1~11] 13.7 Compound and power electron devices and process technology

[14a-B401-3] Open spaces and vacancies in SiO₂/GaN structure probed by means of positron annihilation

〇Akira Uedono¹, K Ueno¹, T. Hosoi², W. Egger³, T. Koschine³, C. Hugenschmidt⁴, M. Dickmann³, H. Watanabe² (1.Tsukuba Univ., 2.Osaka Univ., 3.UnivBwM, 4.TUM)

Keywords:GaN, SiO2, Defect

Open spaces in SiO₂ films deposited on GaN were probed by positron annihilation. The films were fabricated on GaN substrates by using plasma chemical vapor deposition. Vacancy-type defects were introduced into the GaN substrate after 1000°C annealing in O₂ atmosphere due to the diffusion of Ga from the substrate to the SiO₂ film. No out-diffusion of Ga into the SiO₂ film was observed for the annealing in N₂ atmosphere. Thus, the observed out-diffusion of Ga was attributed to the enhanced oxidation of GaN during the annealing in O₂ atmosphere.