Growth of stoichiometric and textured LiNbO3 films on Si by pulsed laser deposition

Laser ablation of single-crystal LiNbO3 in a gas environment is used to gro w films on (100) Si substrates heated to 650 degreesC. The film composition and crystallinity are studied as a function of the nature (reactive, O-2, or inert, Ar) and pressure of the gas environment applied during deposition and cooling-down processes, the laser energy density and the target-substr ate distance. Experimental results show that a gas pressure close to 1 mbar is required to produce stoichiometric films in either O-2 or Ar. The modif ication of the laser energy density and the target-substrate distance allow s us to improve the crystallinity of the films that become textured along t he (006) direction. The influence of the experimental parameters on the fil m properties is discussed in the frame of the formation of a blast wave, th at leads to the focusing of the expanding Li species and thus, to the incre ase of the Li content in the films.