Development of in-situ SEM testing apparatus for observing behavior of material at high magnification during tensile test

In this study, we describe the development of in-situ Scanning Electron Microscopy(SEM) testing apparatus that can continuously observe thin film materials at high magnification during tensile test until fracture, for acquiring mechanical properties and observing failure mechanism. To identify failure mechanism, it is essential to have a tensile testing apparatus capable of performing tests inside a SEM or under a high-magnification optical microscope. The developed apparatus is capable of observing the behavior of the material up to 200 times magnification under an optical microscope and 10,000 times magnification inside SEM until fracture during test. To verify the developed in-situ bidirectional testing apparatus, tensile tests were performed on a copper thin film specimen, and the mechanical properties were compared to those obtained through traditional unidirectional testing. As a result, there was only a slight difference observed in the elastic modulus and ultimate tensile strength, with values of 4.80 % and 0.51 % respectively.