A Critical Review of Thermal Boundary Conductance across Wide and Ultrawide Bandgap Semiconductor Interfaces

Theemergence of wide and ultrawide bandgap semiconductors hasrevolutionized the advancement of next-generation power, radio frequency,and opto- electronics, paving the way for chargers, renewable energyinverters, 5G base stations, satellite communications, radars, andlight-emitting diodes. However, the thermal boundary resistance atsemiconductor interfaces accounts for a large portion of the near-junctionthermal resistance, impeding heat dissipation and becoming a bottleneckin the devices' development. Over the past two decades, manynew ultrahigh thermal conductivity materials have emerged as potentialsubstrates, and numerous novel growth, integration, and characterizationtechniques have emerged to improve the TBC, holding great promisefor efficient cooling. At the same time, numerous simulation methodshave been developed to advance the understanding and prediction ofTBC. Despite these advancements, the existing literature reports arewidely dispersed, presenting varying TBC results even on the sameheterostructure, and there is a large gap between experiments andsimulations. Herein, we comprehensively review the various experimentaland simulation works that reported TBCs of wide and ultrawide bandgapsemiconductor heterostructures, aiming to build a structure-propertyrelationship between TBCs and interfacial nanostructures and to furtherboost the TBCs. The advantages and disadvantages of various experimentaland theoretical methods are summarized. Future directions for experimentaland theoretical research are proposed.

Automated summary

The emergence of wide and ultrawide bandgap semiconductors has revolutionized the advancement of next-generation power, RF, and optoelectronics, but the thermal boundary resistance at semiconductor interfaces hinders heat dissipation. Many new high thermal conductivity materials and techniques have been developed to improve thermal boundary resistance, and simulation methods have been developed to advance understanding. However, there is a large gap between experiments and simulations. This review comprehensively summarizes the experimental and simulation works, aiming to build a structure-property relationship between thermal boundary resistance and interfacial nanostructures and to improve thermal boundary resistance.