(0 0 6)-oriented α-Al2O3 films prepared in CO2–H2 atmosphere by laser chemical vapor deposition using a diode laser

(0 0 6)-oriented α-Al2O3 films were prepared by laser chemical vapor deposition (LCVD) using aluminum acetylacetonate (Al(acac)3) in CO2–H2 atmosphere. The effects of the CO2 mole fraction (FCO2FCO2) and laser power (PL) on the crystal phase, microstructure, and deposition rate (Rdep) were investigated. α- and γ-Al2O3 mixture films were prepared at PL = 90 W (deposition temperature of 818 K), whereas (0 0 6)-oriented single-phase α-Al2O3 films were obtained at PL = 110 W (863 K). The texture coefficient and the grain size of the (0 0 6)-oriented films increased with increasing FCO2FCO2. The orientation of the α-Al2O3 films changed from (0 0 6) to (1 0 4) to (0 1 2) with increasing PL (Tdep). The Rdep of the (0 0 6)-oriented α-Al2O3 films increased with increasing FCO2FCO2.

► Single-phase α-Al2O3 films were prepared by laser CVD under CO2–H2 atmosphere.
► (0 0 6)-oriented, hexagonal α-Al2O3 grains grew even under mild oxidant atmosphere.
► The present deposition rate was 5–500 times higher than thermal CVD.