Papers by Author: Feng Yuan Chen

Abstract: This work uses nanoindentation and nanoscratch to measure the mechanical properties of evaporation copper thin films. The thin film is deposited on a silicon wafer substrate by using the physical vapor deposition method provided by a resistive heating evaporator. The mechanical properties are then determined by indentation test and lateral force test produced by nanoindenter and nanoscratch. The results show that, as the copper thin film is 500nm in thickness and the indentation depth increases from 100nm to 400nm, the Young’s modulus increases from 151GPa to 160GPa while the hardness increases from 2.8GPa to 3.5GPa. Moreover, both the Young’s modulus and the hardness decrease as the thickness of the thin film increases. Besides, the nanoscratch results show that the friction factor also increases as the scratch depth increases, and a thinner film thickness makes a larger friction factor. The results represent the substrate has a significant effect on the mechanical properties of the thin films.

Abstract: This work presents a comparison of numerical simulation and experiment of nanoindentation testing. A commercial finite element code ANSYS is adopted in the numerical simulation, in which elastic-plastic properties are considered. A PMMA specimen and a three side pyramidal Berkovich probe tip is used in the indentation tests. While the elastic-linear workhardening properties are adopted, the numerical results agree well with the experimental data for different indentation loads. It proves the numerical simulation can be used in the small scale analysis.