Thin-Film Engineering of Mechanical Fragmentation Properties of Atomic-Layer-Deposited Metal Oxides

摘要

Mechanical fracture properties were studied for the common atomic-layer-deposited Al O , ZnO, TiO , ZrO , and Y O thin films, and selected multilayer combinations via uniaxial tensile testing and Weibull statistics. The crack onset strains and interfacial shear strains were studied, and for crack onset strain, TiO /Al O and ZrO /Al O bilayer films exhibited the highest values. The films adhered well to the polyimide carrier substrates, as delamination of the films was not observed. For Al O films, higher deposition temperatures resulted in higher crack onset strain and cohesive strain values, which was explained by the temperature dependence of the residual strain. Doping Y O with Al or nanolaminating it with Al O enabled control over the crystal size of Y O , and provided us with means for improving the mechanical properties of the Y O films. Tensile fracture toughness and fracture energy are reported for Al O films grown at 135 °C, 155 °C, and 220 °C. We present thin-film engineering via multilayering and residual-strain control in order to tailor the mechanical properties of thin-film systems for applications requiring mechanical stretchability and flexibility.