Eggshell- and fur-like microstructures of yttrium silicate film prepared by laser chemical vapor deposition

Yttrium silicate (Y–Si–O) films with eggshell- and fur-like microstructures were prepared by laser chemical vapor deposition using a Nd:YAG laser, and tetraethyl orthosilicate (TEOS) and yttrium dipivaloylmethane (Y(dpm)3) precursors. Amorphous Y–Si–O films were prepared at deposition temperature below 1200 K. The crystalline Y–Si–O films with mixtures of Y4.67(SiO4)3O and α-Y2Si2O7 phases were obtained at deposition temperature above 1200 K. y-Y2Si2O7 and X1-Y2SiO5 minor phases were also formed at a higher deposition temperature. At deposition temperature ranging between 1285 and 1355 K, a dome-like structure covered with fine fur-like projections was formed under a total pressure of 3.5 kPa, whereas an eggshell-like structure 200–300 μm in diameter and 10–20 μm in shell thickness was formed at 7.5 kPa. The deposition rate for the Y–Si–O films with fur- and eggshell-like microstructures reached 300 and 1000 μm h−1, respectively.