9. Fundamental Cooling Limits for High Power Density HEMT

The peak power density of GaN high-electron-mobility transistor technology is limited by a hierarchy ofthermal resistances from the junction to the ambient. Here,we explore the ultimate or fundamental cooling limits forjunction-to fluid cooling, which are enabled by advanced thermalmanagement technologies, including GaN–diamond compositesand nanoengineered heat sinks. Through continued attention tonear-junction resistances and extreme flux convection heat sinks,heat fluxes beyond 300 kW/cm2 from individual 2-µm gates and10 kW/cm2 from the transistor footprint will be feasible. Thecooling technologies under discussion here are also applicable tothermal management of 2.5-D and 3-D logic circuits at lowerheat fluxes.

Won, Y., Cho, J., Agonafer, D.D., Asheghi, M., & Goodson, K. E., “Fundamental Cooling Limits for High Power Density GaN Electronics”, IEEE Transactions on Components and Packaging Technologies, vol. 5, pp. 737-744, 2015.