High thermally conductive and electrically insulating 2D boron nitride nanosheet for efficient heat dissipation of high power transistors
High power transistors suffer greatly from inefficient heat dissipation of the hotspots, which elevate the local temperature and significantly degrade the performance and reliability of the high power devices. Although various thermal management methods at package level have been demonstrated, the heat dissipation from non uniform hotspots at micro/nanoscale still persist in the high power transistors. Here, we develop a method for local thermal management using thermally conductive and electrical insulating few layer hexagonal boron nitride (h BN) as heat spreaders and thick counterpart as heat sinks. The electrically insulating characteristic of h BN nanosheet allows it to be intimately contacted with the hotspot region that is located at the gate electrode edge near the drain side of a high electron mobility transistor (HEMT) The high thermal conductivity of h BN nanosheet, which is quantitatively measured by Raman thermography, reduces the temperature of the hotspot by introducing an additional heat transporting pathway. Our DC and radio frequency characterizations of the HEMT show the improvement of saturation current, cut off frequency and maximum oscillation frequency. The finite element simulations show a temperature decrease of ~32 degC at the hotspot with the use of h BN nanosheet. This method can be further extended for the micro/nanoscale thermal management of other high power devices.