Thermal Management Modeling for <i>β</i>-Ga₂O₃-Highly Thermal Conductive Substrates Heterostructures

Abstract

The ultrawide-bandgap (UWBG) (&#x007E;4.8 eV) semiconductor <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-gallium oxide (<inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-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 of <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃ has largely limited the development of these <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃-based high-power electronics. Engineering the thermal transport properties through forming highly thermal conductive <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃-based heterostructures and then improving the corresponding heat dissipation ability may circumvent the low thermal conductivity of <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃. Here, we systematically integrate <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃ with several highly thermal conductive substrates (HTCSs), e.g., AlN (&#x007E;319 W/m K), 4H-SiC (&#x007E;370 W/m K), and diamond (&#x007E;2200 W/m K), and investigate the heat dissipation performance of the <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃-HTCS heterostructures by finite element modeling (FEM). The influence of the interfacial thermal conductance (ITC) between <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃ and HTCSs, the thickness of <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃, and the applied power density on the thermal dissipation capabilities of the <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃-HTCS heterostructures are also discussed. Our results show that, for a heterostructure with 100-nm <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃ and 100-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> HTCSs, 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/m² K under a power 10.1 GW/m². And a large temperature drop from 1668 to 1031 K is obtained if we change the thickness of <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃ from 1010 to 10 nm as for the <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃-AlN heterostructure. Besides, the applied power change from 0.1 to 10.1 GW/m² can 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 of <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-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 forming <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃-HTCS heterostructures to overcome the self-heating issue in <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga₂O₃-based high-power electronics.

Topics & Concepts