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Through silicon via (TSV) is a crucial interconnection structure in 3-D integrated circuits. However, protrusion and intrusion of TSV-Cu caused by annealing could lead to cracking and failure of back-end-of-line (BEOL) layers and TSV interconnects due to mismatch of coefficient of thermal expansion. In this paper, optimizations of TSV interconnects and BEOL layers under annealing process are investigated based on fracture evaluation. Influences of geometrical factors including the TSV geometry dimension, the distance between TSV and BEOL layers, and pitch size of Cu via on energy release rate and J-integral are studied for TSV interconnects and BEOL layers with cracks.Effect of material properties for low k dielectrics on interfacial fracture of BEOL layers and TSV interconnects is also given. Optimized geometrical factors and optimized material properties of low k dielectrics are presented in this paper. Fracture-based method sheds a light on emerging electronic packaging optimization. K E Y W O R D Sannealing process, BEOL layer, energy release rate, J-integral, TSV interconnect

Herein, twinning‐induced plasticity (TWIP) steel having large deformation is rolled at different rolling temperatures to improve the tensile strength and retain a certain plastic deformation capacity. Based on X‐ray diffraction and transmission electron microscope analysis, β‐Mn is found as the precipitate at the grain boundary during the warm‐rolling process (500–650 °C). To investigate the impact of β‐Mn on the tensile properties, the microstructure of the TWIP steel rolled at the temperature value of 600 °C is observed by carrying out electron backscatter diffraction and scanning electron microscope measurements. The intergranular β‐Mn phase can help the material to accumulate geometric necessary dislocation (GND) density, inhibit crack propagation, as well as improve the strength and plasticity of the material. Once TWIP steel is warm‐rolled above the temperature value of 600 °C, and serrated flow appears in the tensile process, which is also conducive to improving the material properties.