First Demonstration and Physical Insights into Time-Dependent Breakdown of Graphene Channel and Interconnects.

A prolonged operation of Graphene FET and interconnects mandate the assessment of temporal evolution of degradation of the material. Contrary to bulk semiconductors, which break only above a critical field, the time-dependent degradation and consequent failure of graphene has been discovered, which precludes the existence of failure threshold and manifests as a potential defect-assisted aging issue for graphene and other 2D material-based devices. Unlike catastrophic failures, which are triggered during redistribution of excess energy, the role of reaction kinetics (time) in inflicting defect-by -defect damage to graphene channel is revealed. Time-evolution of defects in graphene channel while exploring possible pathways through which heat dissipates across the device has been studied on-the-fly using an integrated micro-Raman setup. The role of metal-graphene interface and the substrate in removing excess heat from graphene channel is discussed, while emphasizing the need for sp-hybridized carbon atoms at metal-graphene interface for reliable, long-term operation of graphene-based devices.