Oxide charge evolution under crystallization of amorphous LieNbeO films

• Main Authors: Sumets, M., Ievlev, V., Belonogov, E., Dybov, V., Serikov, D., Kotov, G., Turygin, A.
• Format: Article
• Language: English
• Published: H. : ĐHQGHN 2020
• Subjects: LiNbO3; Crystallization; Magnetron sputtering; Oxide charge; Annealing
• Online Access: http://repository.vnu.edu.vn/handle/VNU_123/89313; https://doi.org/10.1016/j.jsamd.2020.02.006
• Institution: Vietnam National University, Hanoi

LieNbeO amorphous films were deposited onto Si substrates by the radio-frequency magnetron sputtering method in an Ar environment and an Ar(60%)þO2(40%) gas mixture. A positive effective fixed oxide charge Qeff having negative, -Qeff, and positive, þQeff, components, exists in the as-grown heterostructures. -Qeff is located near the substrate/film interface, whereas þ Qeff is determined by a deficit of Li and O (vacancies) in the bulk of LieNbeO films. As-grown films crystallized under thermal annealing (TA) at temperatures up to 600 C and revealed the formation of polycrystalline LiNbO3. TA at about 520 C resulted in the formation of the second phase LiNb3O8, increasing þ Qeff, and compensating -Qeff entirely. The dielectric constants of the as-grown films exhibit two peaks at the annealing temperatures of 450 C and 550 C, which are attributed to the total crystallization and recrystallization of the LN films under TA, respectively.