Moderate temperature and high-speed synthesis of α-Al2O3 films by laser chemical vapor deposition using Nd:YAG laser

Al2O3 films were prepared at deposition temperatures (Tdep) from 980 to 1230 K by laser chemical vapor deposition (LCVD) using the continuous wave of a Nd:YAG laser with laser power (PL) up to 260 W. γ-Al2O3 films were obtained at Tdep < 1100 K, whereas α-Al2O3 films were obtained at Tdep > 1100 K. γ-Al2O3 films were morphologically characterized by a cone-like structure, while α-Al2O3 films had hexagonal faceted grains. The highest deposition rate (Rdep) of γ-Al2O3 film was 570 μm h− 1, while that of α-Al2O3 film was 250 μm h− 1. α-Al2O3 films in a single phase were obtained at 170 K lower in Tdep and 100 times higher in Rdep than those by conventional thermal CVD.