Effects of laser power on the growth of polycrystalline AlN films by laser chemical vapor deposition method

Polycrystalline aluminum nitride (AlN) films were prepared by laser chemical vapor deposition method using aluminum acetylacetonate and ammonia as source materials. The effects of deposition conditions on the crystal phase, composition and microstructure were investigated. Polycrystalline AlN films were prepared at a laser power above 100 W and a deposition temperature above 803 K. The microstructure of AlN film changed from aggregated grains to faceted grains to pyramidal grains with increasing laser power and with decreasing total pressure.