Near-Junction Thermal Management for Wide Bandgap Devices

Near-junction thermal management is critical to achieving the promise of electronic and photonic devices using wide bandgap materials. In such devices, including GaN HEMTs in PAs, the thermal resistance associated with the "near-junction" region dominates the heat removal path and is often as large as the thermal resistance of all the other elements in the resistance chain. As part of DARPA's portfolio in Thermal Management Technologies (TMT), efforts are underway to develop transformative, paradigm-changing cooling techniques. This paper will briefly review the thermal management needs of WBG devices and DARPA's Thermal Management Technologies portfolio, with emphasis on the goals and status of these efforts relative to the current State-of-the-Art. Attention will then turn to promising options in near-junction cooling and the challenges inherent in realizing their potential for WBG device thermal management.