A microsystem for the fracture characterization of polysilicon at the micro-scale

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• 作者：A. Coriglianop>ap> ; A. Ghisip>ap>p> ; p>p>aldo.ghisi@polimi.itp> ; G. Langfelderp>bp> ; A. Longonip>bp> ; F. Zaragap>bp> ; A. Merassip>cp>
• 关键词：Microsystem ; Polysilicon fracture ; Mechanical testing ; Cohesive crack simulation
• 刊名：European Journal of Mechanics - A/Solids
• 出版年：2011
• 出版时间：March-April 2011
• 年：2011
• 卷：30
• 期：2
• 页码：127-136
• 全文大小：1612 K

文摘

To characterize the effective fracture energy G_IC of polysilicon wafers at room temperature, an on-chip MEMS test structure has been designed and fabricated. The device can provide fatigue pre-cracking at the notch apex and subsequently impose a monotonical load up to failure. The proposed procedure combines the experimental data with outcomes of numerical simulations. A continuously monitored decrease in stiffness of the system is linked to the crack length and the effective fracture energy for the non-standard geometry of the testing device. An average value of G_IC = 12.0 ± 1.8 N mp>−1p> is found. These values are then used in numerical micro-scale fracture analyses taking into account the material heterogeneity due to the grain structure and reproducing the crack propagation process with a cohesive approach.