Axial compression was conducted on micro-pillars, in which polycrystalline Cu thin films were sandwiched between CrN and Si. Plastic flow of Cu was achieved, when the Cu films are inclined either at 90° or 45° with respect to the pillar axis. The texture of Cu films was altered by changing the template on which film growth occurred. The Cu microstructure was further altered by post-deposition annealing. The flow stress shows little dependence on the film texture in the as-deposited state. However, annealing influences the flow stress of confined Cu films significantly. The implications on strain gradient plasticity models are discussed.
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Partial project supports from NSF OIA-1541079 and LA BoR LEQSF(2013-16)-RD-B-01 are gratefully acknowledged.
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Mu, Y., Zhang, X., Hutchinson, J.W. et al. Dependence of confined plastic flow of polycrystalline Cu thin films on microstructure. MRS Communications 6, 289–294 (2016). https://doi.org/10.1557/mrc.2016.20