The formation mechanism of (001) preferred orientation for anatase TiO2 film prepared by DC pulsed magnetron sputtering

• Published in: Vacuum 2021-08, Vol.190, p.110287, Article 110287
• Main Authors: Zhang, Yi, Liu, Zhihui, Zhang, Xin, Wang, Qizhen, Wang, Quan, Wang, Hualin, Jiang, Weiwei, Liu, Shimin, Liu, Chaoqian, Wang, Nan, Cui, Yunian, Ma, Yanping, Ding, Wanyu, Liu, Jindong
• Format: Article
• Language: English
• Subjects: Anatase structure; Dynamic scaling of growing interface; preferred orientation; Sputtering power density; TiO2 film
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2021.110287

TiO2 films were deposited by DC pulsed magnetron sputtering with different sputtering power density (SPD). Then, as-deposited TiO2 films were annealed at 600 °C and the anatase TiO2 films were obtained. XPS results showed Ti/O atom ratio was kept at 1/(1.94 ± 0.04) for all as-deposited and annealed TiO2 films. XRD results showed that the annealed TiO2 films displayed obvious anatase (001) preferred orientation, which was deposited with SPD in 0.83 W/cm2. The cross-section TEM results showed that annealed TiO2 film with anatase (001) preferred orientation consisted of a small quantity of columnar crystals and a majority of equiaxed crystals, which [001] crystallographic axis was parallel to the normal direction of film. AFM results revealed that with SPD in 0.83 W/cm2, the dominated diffusion effect controlled TiO2 film growth process with Volmer-Weber mode, which contained the nano-size anatase crystal nuclei. The [001] crystal orientation of anatase crystal nuclei was uniform parallel to the normal direction of TiO2 film growth surface. During the annealing process, the nano-size anatase crystal nuclei grew and coalesced into the large anatase grains without the change of [001] crystal orientation, which resulted in TiO2 film with obvious (001) preferred orientation. •TiO2 film was prepared by conventional DC pulsed magnetron sputtering technique.•As-deposited TiO2 film contained nano-size crystal nuclei with uniform [001] axis.•Annealed TiO2 film displayed grains with uniform [001] axis and (001) preferred orientation.•Diffusion effect controlled TiO2 film growth process with Volmer-Weber mode.