Title :
X-ray micro-beam diffraction measurement of the effect of thermal cycling on stress in Cu TSV: A comparative study
Author :
Okoro, Chukwudi ; Levine, Lyle E. ; Ruqing Xu ; Hummler, Klaus ; Obeng, Yaw
Author_Institution :
Semicond. & Dimensional Metrol. Div., Nat. Inst. of Stand. & Technol. (NIST), Gaithersburg, MD, USA
Abstract :
Microelectronic devices are subjected to constantly varying temperature conditions during their operational lifetime, which can lead to their failure. In this study, we examined the impact of thermal cycling on the evolution of stresses in Cu TSVs using synchrotron-based X-ray micro-diffraction. Two test conditions were analyzed: as-received and 1000 cycled samples. The principal and shear stresses in the 1000 cycled sample were five times greater than in the as-received sample. This was attributed to the increased strain hardening upon thermal cycling. The variation in stresses with thermal cycling is a clear indication that the impact of Cu TSV proximity on front-end-of-line (FEOL) device performance will fluctuate throughout the lifetime of the 3D stacked dies, and thus should be accounted for during FEOL keep-out-zone design rule development.
Keywords :
X-ray diffraction; copper; integrated circuit design; synchrotron radiation; thermal stresses; three-dimensional integrated circuits; work hardening; 3D stacked dies; Cu; FEOL keep-out-zone design rule development; TSV; X-ray microbeam diffraction measurement; front-end-of-line device performance; microelectronic devices; operational lifetime; shear stress; strain hardening; synchrotron-based X-ray microdiffraction; temperature conditions; thermal cycling; Stress; Stress measurement; Temperature measurement; Thermal stresses; Through-silicon vias; Uncertainty; X-ray diffraction;
Conference_Titel :
Electronic Components and Technology Conference (ECTC), 2014 IEEE 64th
Conference_Location :
Orlando, FL
DOI :
10.1109/ECTC.2014.6897516
