Effects of Film Thickness on the Residual Stress of Vanadium Dioxide Thin Films Grown by Magnetron Sputtering

Vanadium dioxide (VO2) thin films of different thicknesses were prepared by regulating the deposition time (2, 2.5, 3, and 3.5 h). The impact of deposition time on the microstructure, surface morphology, and cross-section morphology was investigated. The results showed that the grain size increased with the film thickness. Meanwhile, the influence of film thickness on the residual stress was evaluated by X-ray diffraction. The phenomenon of compressive-to-tensile stress transition was illustrated as the thickness increased. The change of dominant mechanism for residual stress was used for explaining this situation. First, the composition of residual stress indicates that growth stress play a key role. Then, the effect of atomic shot peening can be used to explain the compressive stress. Lastly, the increased grain size, lower grain boundary density, and tight effect in the progress of film growth cause tensile stress.

Automated summary

Vanadium dioxide (VO2) thin films of various thicknesses were prepared by adjusting the deposition time. The impact of deposition time on the microstructure, surface morphology, and cross-section morphology was investigated. The grain size was found to increase with the film thickness. X-ray diffraction analysis revealed a transition from compressive to tensile stress as the film thickness increased, which could be explained by changes in the dominant mechanism for residual stress, including growth stress, atomic shot peening, and the effect of grain size and grain boundary density on film growth.