Impact of interfacial layer structures on thermal boundary resistance in amorphous oxide heterointerfaces: a molecular dynamics study

Abstract Thermal boundary resistance (TBR) at material interfaces is crucial to thermal management in modern semiconductor devices. Using non-equilibrium molecular dynamics simulations, we examined two types of interfacial layer structures: compositionally graded and void-interface ones. For compositionally graded structures, a hypothetical metal-oxide based on SrO was used to vary the interfacial composition and atomic mass, revealing their impact on the TBR. Higher atomic mass of metal increased TBR owing to mismatch in the vibrational density of states. However, thicker interfacial regions reduced this mismatch, reducing TBR by facilitating vibration bridging between the bulk regions. By contrast, simulations with void-interface structures conducted on Al 2 O 3 /SiO 2 systems revealed that TBR is universally proportional to the inverse of interfacial atomic density, regardless of void distribution. These findings helped elucidate the mechanisms governing TBR at MO/SiO 2 interfaces and offered a framework for designing interfacial structures to optimize heat transport in semiconductor devices.