Graphene quilts for thermal managementof high-power Gan transistors

摘要

Self-heating is a severe problem for high-power gallium nitride (Gan) electronic andoptoelectronic devices. Various thermal management solutions, for example, flip-chip bondingor composite substrates, have been attempted. However, temperature rise due to dissipatedheat still limits applications of the nitride-based technology. Here we show that thermalmanagement of Gan transistors can be substantially improved via introduction of alternativeheat-escaping channels implemented with few-layer graphene—an excellent heat conductor.The graphene–graphite quilts were formed on top of AlGan/Gan transistors on siC substrates.using micro-Raman spectroscopy for in situ monitoring we demonstrated that temperatureof the hotspots can be lowered by -20°C in transistors operating at -13Wmm~(-1), whichcorresponds to an order-of-magnitude increase in the device lifetime. The simulations indicatethat graphene quilts perform even better in Gan devices on sapphire substrates. The proposedlocal heat spreading with materials that preserve their thermal properties at nanometre scalerepresents a transformative change in thermal management.