Characterization of Nanomechanical Properties and Scratch Hardness of (111) Nanotwinned Copper Thin Film in Ambient and Slurry Conditions

Abstract

Nanotwinned copper possesses a distinctive structure with higher mechanical strength and stability without compromising on resistivity. This study aimed to characterize the nanomechanical properties along with the scratch hardness of the (111) nanotwinned copper thin film wafer in ambient and slurry conditions by triboindenter. Experiments were performed on Hysitron TI 980 Triboindenter using Berkovich and conical indenter for nanoindentation and nano scratch, respectively. We studied the impact of nanotwinned structures on quasistatic and scratch hardness of copper thin film wafers given the potential applicability of nanotwinned copper thin films as interconnects. CMP was extensively applied to obtain the nanoscale surface finish required in the semiconductor micro-nano fabrication industry. The nanomechanical properties of (111) nanotwinned copper thin film wafer with passivation in polishing slurry conditions were imperative parameters to study the polishing behavior of material. Hardness, Young's modulus, and scratch hardness of the nanotwinned copper thin film specimens were evaluated by nanoindenter in ambient and slurry conditions. Results of this study with characteristic parameters of (111) nanotwinned copper thin film wafer can be further used to estimate the material removal of chemical mechanical polishing for high volume production of IC devices in future work.