Thermal Management Modeling for β-Ga2O3-Highly Thermal Conductive Substrates Heterostructures

The ultrawide-bandgap (UWBG) (~4.8 eV) semiconductorβ-gallium oxide (β-Ga2O3) gives promise to the next generation of high-power electrical devices owing to its high-power conversion efficiency and current handling capability. However, the self-heating issue caused by the low thermal conductivity ofβ-Ga2O3has largely limited the development of theseβ-Ga2O3-based high-power electronics. Engineering the thermal transport properties through forming highly thermal conductiveβ-Ga2O3-based heterostructures and then improving the corresponding heat dissipation ability may circumvent the low thermal conductivity ofβ-Ga2O3. Here, we systematically integrateβ-Ga2O3with several highly thermal conductive substrates (HTCSs), e.g., AlN (~319 W/m K), 4H-SiC (~370 W/m K), and diamond (~2200 W/m K), and investigate the heat dissipation performance of theβ-Ga2O3-HTCS heterostructures by finite element modeling (FEM). The influence of the interfacial thermal conductance (ITC) betweenβ-Ga2O3and HTCSs, the thickness ofβ-Ga2O3, and the applied power density on the thermal dissipation capabilities of theβ-Ga2O3-HTCS heterostructures are also discussed. Our results show that, for a heterostructure with 100-nmβ-Ga2O3and 100-μ mHTCSs, the maximum temperature can be decreased from 1860 to 1153 K for AlN HTCS when the interfacial thermal boundary conductance is changed from 10 to 310 MW/m2K under a power 10.1 GW/m2. And a large temperature drop from 1668 to 1031 K is obtained if we change the thickness ofβ-Ga2O3from 1010 to 10 nm as for theβ-Ga2O3-AlN heterostructure. Besides, the applied power change from 0.1 to 10.1 GW/m2can bring a temperature change from 306 to 1110 K. The safety operating region of the corresponding heterostructures considering the interfacial thermal boundary conductance, the thickness ofβ-Ga2O3, and the applied power, i.e., the temperature is lower than 575 K, is then suggested. Our results here propose a new thermal management strategy via formingβ-Ga2O3-HTCS heterostructures to overcome the self-heating issue inβ-Ga2O3-based high-power electronics.