Young´s modulus measurement method for nano-scale film materials by using MEMS resonator array

This paper describes a quantitative measurement method for Young´s modulus of nanometer-thick film materials by using a MEMS resonator array. The MEMS resonators fabricated by silicon micromachining techniques were designed to be driven at their resonant frequencies from 6.0 kHz to 35.5 kHz. From the difference in resonant frequencies between before and after deposition of these films onto the resonators, we successfully measured the Young´s moduli of Al and plasma-polymerization films made from CH₄ and CHF₃ gases. The obtained Young´s moduli of Al, CH₄ and CHF₃-derived polymer films were found to be 60.4, 35.7, and 30.0 GPa on average, respectively, and showed no film thickness dependency in the range from 50 to 150 nm. The obtained values for all the films by the resonance tests were comparable to those by tensile and nanoindentation tests. The proposed technique is effective for directly measuring Young´s modulus of nanometer-thick film materials.