  The needs for efficient heat removal and superior thermal conduction in
nano/micro devices have triggered tremendous studies in low-dimensional
materials with high thermal conductivity. Hexagonal boron nitride (h-BN) is
believed to be one of the candidates for thermal management and heat
dissipation due to its novel physical properties, i.e. thermal conductor and
electrical insulator. Here we reported interfacial thermal resistance between
few-layer h-BN and its silicon oxide substrate using differential 3 omega
method. The measured interfacial thermal resistance is around ~1.6*10-8 m2K/W
for monolayer h-BN and ~3.4*10-8 m2K/W for 12.8nm-thick h-BN in metal/h-BN/SiO2
interfaces. Our results suggest that the voids and gaps between substrate and
thick h-BN flakes limit the interfacial thermal conduction. This work provides
a deeper understanding of utilizing h-BN flake as lateral heat spreader in
electronic and optoelectronic nano/micro devices with further miniaturization
and integration.
