AlCl₃・NH₃-H₂系気相反応によるAlN膜の合成

抄録

Aluminium nitride (AlN) films were prepared by the chemical vapor deposition in the AlCl₃⋅NH₃-H₂ system under an atmospheric pressure. The effects of the synthetic conditions on the deposition rate and the morphology of AlN films were discussed. The deposition rate decreased with increasing distance (X) between the upstream end of the graphite supporting Al₂O₃ substrates and Al₂O₃ substrates and with decreasing deposition temperature (T_d). The effect of AlCl₃⋅H₃ concentration (C_A) on the deposition rate was very complicated. Generally, the deposition rate increased with increasing C_A but decreased between C_A=2.5 and 3.4vol%. The morphology of AlN crystals in the films deposited at 800°C depended on the X value; fine (X≅1cm), columnar (X≅2cm), needle-like (X≅3cm), and then whisker-like crystals (X≅4cm). With decreasing T_d or increasing C_A, the smooth surface AlN films turned rough.