| With t he de velopment of N ano-technology, more a nd m ore de vices c ome out consecutively. A s ignificant a pplication i s M EMS, w hich i s w idely u sed s uch as Micro-fluidic chips, synthetic biology, and other fields. However, MEMS devices are mainly damaged b y the delamination and rupture of thin films. Consequently, the investigation of the thin film damage is important for predicting the life of MEMS. There are two failure modes of the thin film, one is the bifurcation and fracture under the tension load, and another is buckling and delamination under the compression. To research the question of thin film destruction form, not only the way of simulation and numerical analysis can be used by establishing corresponding mechanical models, but also prepare certain plan to carry on the experiment. In resent years, many progresses has been achieved by some researchers both in calculation and experiment.In this paper, the bifurcation of the deformation and fracture under the stretch load is researched by experiment. In the experiment, the film/substrate structure is used as a specimen, w hich on t he s ubstrate de posit 100nm, 150nm, 200nm three different thicknesses aluminum films. Then the experiment is advanced by our own designed loading device. OLYMPUS optical microscope is used to observe the change of the topography of the film surface. In addition, we record the destruction of the film and the corresponding size of the load and displacement. Last, the effect of film thickness t o t he phenomena of the bi furcation and f racture c an be f ound out b y comparing the experiment results. The experiment result show that: with the film thickness increased, the relevant rupture strain also increased; and when there are cracks come out on t he film surface, the crack density along the loading direction depends on the thickness of film and failure stain.In order to study the different bifurcation and fracture phenomena of thin metal film unde r the te nsion load affected by di fferent me tal ma terials, based on t he destruction of a luminum f ilm w e di scussed a bove, t he f ilm/substrate i s us ed a s a specimen for the comparative experiments, which depositing 300nm, 500nm, 650nm, 800nm and 1μm five different t hicknesses co pper f ilms on t he s ame s hape a nd thickness P ET s ubstrates. T he ex periment is s till advanced by our ow n de signed loading device. In the cause of accurately observe the critical state of the bifurcation, taking i nto a ccount t hat the de formation of me tal f ilm ha s a hug e impa ct to the resistance of the film, so the micro-resistance measuring instrument is used to monitor the change of resistance for the film in the experiment to determine the critical stress and s train w hen t he i nstability oc curs on the me tal f ilm. OLYMPUS optical microscope and the CCD are still used to record the change of the topography of the film s urface. Some va luable c onclusions c an be obt ained b y analyzing t he experimental image and data, and also compare the experiment results of aluminum. |
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