LiNbO3 thin films deposited on Si substrates: a morphological development study

LiNbO3 thin films were grown on Si (1 1 1) substrates by radio-frequency (r.f.) sputtering and/or spray pyrolysis techniques. By comparing the chemical, structural and textural properties of such as-deposited films, a new two-step growth process was developed, involving the combination of the last two methods. By creating a high nucleation density by r.f. sputtering and then enhancing the crystallinity and oriented growth of the films by pyrosol, an easier control of the nucleation and growth stages could be achieved. Using this refined growth process, we succeeded in both controlling the 〈0 0 1〉-preferred orientation and obtaining films of good uniformity with respect to their morphological and topological characteristics. Experimental data as well as general guidelines for thin film synthesis are discussed with respect to the deposition method, the film growth mode and/or the resulting morphology.