Scotch-Tape Surface Wrinkling Based Thin-Film Material Properties Extraction

Abstract

This paper presents a new simple method to measure thin film material properties using scotch-tape surface wrinkling. Metal thin films have been deposited on polymer substrates by e-beam evaporation. After patterned by photolithography and wet etching, long and narrow thin metal layers have been transferred by peel-off onto the scotch tape. The effect of velocity of scotch tape peel-off on the metal thin film transfer from polymer substrates to the scotch tape has been investigated. After transfer, metal thin film wrinkling patterns have been established on the scotch tape due to mechanical properties mismatch between the two materials. The wrinkling patterns have been characterized in term of amplitude and wavelength and they are compared with FEM (Finite Element Method) buckling simulation results for material properties extraction. By consequence, elastic moduli of 300 nm-thick gold film and a multilayer of 30 nm Ti on 300 nm Au have been found 147 GPa and 885 GPa based on the measured wavelength of the wrinkling films.