Pronounced electromigration of GaInSn/Cu interconnects under super low critical current density

Abstract Ga-based alloys has been paid increasingly attention as a promising material choice for constructing flexible and stretchable electronics. The interfacial stability of non-bonding GaInSn/Cu interconnect plays a critical role in determining its electrical performance. Here, we report an interesting electromigration phenomenon under current flux and verify the atoms migration through the GaInSn path from cathode to the anode. The critical current density for inducing the room temperature electromigration of Cu/GaInSn/Cu is two orders of magnitude lower than that of other electromigration system. When Ni which has a higher bond strength is employed to substitute Cu anode, due to the small number of intermetallic compounds embryos, the electromigration resistance of anode material is substantially improved. Our findings will provide good insights into the electromigration of Cu/GaInSn/Cu and may offer a critical first step toward the design of high- performance Ga-based soft and stretchable electronics.