Cooling Limits for GaN HEMT Technology

The peak power density of GaN HEMT technology is limited by a hierarchy of thermal resistances from the junction to the ambient. Here we explore the ultimate or fundamental cooling limits made possible by advanced thermal management technologies including GaN-diamond composites and nanoengineered heat sinks. Through continued attention to near-junction resistances and extreme flux convection, power densities that may exceed 50 kW/cm2 - depending on gate width and hotspot dimension - are feasible within 5 years.