Nanomechanical properties of pure and doped Ta2O5 and the effect of microwave irradiation

The nanomechanical properties of pure and doped Ta2O5 films (100 nm) on Si, and the effect of short time (10 s) microwave irradiation are studied by nanoindentation testing. The local mechanical parameters as determined by the force measuring ability of atomic force microscopy are compared with the data from both the Oliver-Pharr nanoindentation technique and the continuous stiffness measurements. The impact of the dopant type (Hf and Al) on the surface morphology, elastic modulus and hardness of the films is determined. The results reveal an increase in elastic modulus and hardness after the doping. The irradiation produces a little lower values of mechanical parameters. The results are discussed in juxtaposition with the established previously strong effect of irradiation on the electrical properties of Ta2O5-based stacks. From device perspective point of view Hf-doped Ta2O5 is noteworthy for micro-electro-mechanical system applications.