Low-temperature deposition of α-Al2O3 films by laser chemical vapor deposition using a diode laser

We prepared Al2O3 films by laser chemical vapor deposition (LCVD) using a diode laser and aluminum acetylacetonate (Al(acac)3) precursors and investigated the effects of laser power (PL), deposition temperature (Tdep), and total pressure (Ptot) in a reaction chamber on the crystal phase, microstructure, and deposition rate (Rdep). An amorphous phase was obtained at PL = 50 W, whereas an α-phase was obtained at PL > 100 W. At PL = 150 and 200 W (1 0 4)- and (0 1 2)-oriented α-Al2O3 films were obtained, respectively. The Rdep of α-Al2O3 films increases with decreasing PL and Ptot. Single-phase α-Al2O3 film was obtained at Tdep = 928 K, which is about 350 K lower than that obtained by conventional thermal CVD using Al(acac)3 precursor.