|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Phase Stability, Phase Transformations, and Reactive Phase Formation in Electronic Materials XV
||Low-temperature Pressure-less Silver-to-silver Direct Bonding at Ambient Condition: Part II-Mechanistic Study
||Shih-kang Lin, Shijo Nagao, Chulmin Oh, Hao Zhang, Yu-chen Liu, Shih-guei Lin, Katsuaki Suganuma
|On-Site Speaker (Planned)
Low-temperature interconnection technology that produces stable joints for high-temperature operations is demanding for applications ranging from three-dimensional integrated circuits to power electronics. Oxides usually hinder metallic joint formation due to reduction of effective contact areas. Nevertheless, sound silver-to-silver joints have been successfully fabricated without any fluxing agent at low temperatures under ambient condition. However, the mechanism of this unusual phenomenon is not clear. Here we uncover the role of oxygen and clarify the necessity of oxides in the silver-to-silver bonding process. It involves grain-boundary liquation due to extremely high autogenetic oxygen partial pressure at grain-boundaries. This Ag-O fluid was “squeezed” out from the grain boundaries. Upon the sudden reduction of pressure, the Ag-O fluid was quenched while oxygen was evaporated, leaving amorphous Ag behind. Subsequent nano-crystallization and abundant grain formation of silver occurred to form sound joints. The reaction mechanisms are elaborated, which opens a door for new interconnection technology.
||Planned: A print-only volume