Phase formation and microstructure evolution in Cu/In/Cu joints. (April 2019)

• Record Type: Journal Article
• Authors: Chiu, Y.S.; Yu, H.Y.; Hung, H.T.; Wang, Y.W.; Kao, C.R.
• Is Part Of: Microelectronics and reliability. Volume 95(2019)
• Page Start: 18
• Page End: 27
• Publication Date: 2019-04
• Subjects: 3D-IC integration -- SLID -- Interfacial reactions -- Activation energy -- In; Electronic apparatus and appliances -- Reliability -- Periodicals; Miniature electronic equipment -- Periodicals; Appareils électroniques -- Fiabilité -- Périodiques; Équipement électronique miniaturisé -- Périodiques; Electronic apparatus and appliances -- Reliability; Miniature electronic equipment; Periodicals; 621.3815
• DOI: 10.1016/j.microrel.2019.02.004
• Languages: English
• ISSNs: 0026-2714

Abstract

Abstract: In this study, Cu/In/Cu sandwich structures were fabricated at 180 °C, which was followed by aging at 245 °C, 273 °C, and 290 °C for different time periods. The microstructural evolutions were investigated using scanning electron microscopy (SEM), electron backscattering diffraction (EBSD), and energy dispersive X-ray spectroscopy (EDS). The results show that the intermetallic compounds formed included Cu11 In9, Cu2 In, and Cu7 In3, depending on the aging conditions. The activation energies for the growths of Cu2 In and Cu7 In3 are estimated to be 17 kJ/mol and 40 kJ/mol, respectively. The compound Cu2 In tended to encircle voids, and wavy edges formed presumably due to the grain orientations of the Cu substrates. The mechanical properties of the compounds were measured by the nanoindentation test. The results show that CuIn compounds have better mechanical properties than CuSn compounds. Highlights: The activation energy of Cu2In and Cu7In3 were obtained in this paper. The voids behavior and the wavy interface phenomenon of Cu/In system were discussed in the literature. EBSD analysis was proposed to discuss the grain orientations of this system. The values of hardness and Young's moduli of Cu/In system were obtained in the research.