A New Microtensile Tester for the Study of MEMS Materials with the Aid of Atomic Force Microscopy, Exp

ABSTRACT—An apparatus has been designed and imple-mented to measure the elastic tensile properties (Young’s modulus and tensile strength) of surface micromachined polysilicon specimens. The tensile specimens are “dog-bone” shaped ending in a large “paddle ” for convenient electrostatic or, in the improved apparatus, ultraviolet (UV) light curable adhesive gripping deposited with electrostatically controlled manipulation. The typical test section of the specimens is 400 µm long with 2 µm × 50 µm cross section. The new device supports a nanomechanics method developed in our laboratory to acquire surface topologies of deforming spec-imens by means of Atomic Force Microscopy (AFM) to de-termine (fields of) strains via Digital Image Correlation (DIC). With this tool, high strength or non-linearly behaving materi-als can be tested under different environmental conditions by measuring the strains directly on the surface of the film with nanometer resolution. KEY WORDS—Mechanical properties, microtensile testing, AFM, digital image correlation, MEM