High-throughput wafer-scale microtensile testing of thin films

This paper reports on the mechanical characterization of thin films using the microtensile technique performed for the first time at the wafer-scale. Multiple test structures are processed and sequentially measured on the same substrate, thus eliminating delicate handling of individual samples. The current layout uses 26 test structures evenly distributed on a 4-inch silicon wafer, each of them having microtensile specimens. A fully automated, high-throughput setup has been developed, which enables the fast acquisition of data with statistical relevance for the reliable extraction of material properties. The technique has been successfully applied to mum- and sub-mum-thick films. These include brittle materials, such as polycrystalline silicon (poly-Si) and silicon nitride (SiN_x), and ductile materials such as aluminum (Al). The extraction of mechanical parameters such as the Young´s modulus E, mean tensile strength sigma tilde_u, Weibull modulus m and 0.2% offset yield strength sigma_0.2% is demonstrated.