Rapid On-Chip Healing of Metal Thin Films

摘要： Self-healing behavior, the ability to autonomously counteract damage, is observed in some inorganic materials, and it has recently been extended to various artificial systems. In metals, healing usually requires thermal activation by a furnace treatment that stimulates damage repair. High temperature exposure, however, renders these routes incompatible with temperature-sensitive systems such as on-chip microelectronic components. In this work, designing Ni/Al multilayers as on-chip heat sources, a concept for on-demand healing of metal films that no longer relies on external annealing, is demonstrated. The process is based on harvesting a solitary self-sustained heat wave that is produced by a solid-state reaction in the heat source to weld cracks in different metal films. Healing is activated at room temperature with a remarkably small current input and in situ probing reveals a large conductance recovery up to 500 nm wide cracks within 1 ms, orders of magnitude faster than furnace-based approaches. Intrinsic heat source healing represents a unique concept for rapid on-chip healing of metal films that will provide new flexibility to prevent failure in inaccessible electronic systems: from implantable healthcare devices, to space probe instrumentation.