Thermal conductivity measurements of sub-surface buried substrates by steady-state thermoreflectance

Measuring the thermal conductivity of sub-surface buried substrates is significant practical interests. However, this remains challenging with traditional pump–probe spectroscopies due to their limited penetration depths. Here, we experimentally and numerically investigate TPD recently developed optical technique steady-state thermoreflectance (SSTR) explore its capability for measuring properties substrates. The conventional definition (i.e., depth at which temperature drops 1/e value maximum surface temperature) does not truly represent upper limit how far beneath SSTR can probe. For estimating uncertainty measurements a substrate priori, sensitivity calculations provide best means. Thus, detailed are provided guide future measurements. Due nature SSTR, it measure that traditionally by transient techniques, exemplified three control samples. We also discuss required criteria isolate film. Our study establishes as suitable characterizations in typical device geometries.