Stencil mask methodology for the parallelized production of microscale mechanical test samples

Abstract

A new methodology to parallelize the production of micromechanical test samples from bulk materials is reported. This methodology has been developed to produce samples with typical gage dimensions on the order of 20-200 μm, and also to minimize the reliance on conventional focused ion beam fabrication methods. The fabrication technique uses standard microelectronic process methods such as photolithography and deep-reactive ion etching to create high aspect ratio patterned templates-stencil masks-from a silicon wafer. In the present work, the stencil mask pattern consists of a linear row of tensile samples, where one grip of each sample is integrally attached to the bulk substrate. Once fabricated, the stencil mask is placed on top of a pre-thinned substrate, and the pattern and substrate are co-sputtered using a broad ion beam milling system, which ultimately results in the transfer of the mask pattern into the substrate. The methodology is demonstrated using a Si stencil mask and a polycrystalline Ni foil to manufacture an array of metallic micro-tensile samples.