  Scanning thermal microscopy (SThM) - a type of scanning probe microscopy that
allows mapping thermal transport and temperatures in nanoscale devices, is
becoming a key approach that may help to resolve heat dissipation problems in
modern processors and develop new thermoelectric materials. Unfortunately,
performance of current SThM implementations in measurement of high thermal
conductivity materials continues to me limited. The reason for these
limitations is two-fold - first, SThM measurements of high thermal conductivity
materials need adequate high thermal conductivity of the probe apex, and
secondly, the quality of thermal contact between the probe and the sample
becomes strongly affected by the nanoscale surface corrugations of the studied
sample. In this paper we develop analytical models of the SThM approach that
can tackle these complex problems - by exploring high thermal conductivity
nanowires as a tip apex, and exploring contact resistance between the SThM
probe and studied surface, the latter becoming particularly important when both
tip and surface have high thermal conductivities. We develop analytical model
supported by the finite element analysis simulations and by the experimental
tests of SThM prototype using carbon nanotube (CNT) at the tip apex as a heat
conducting nanowire. These results elucidate vital relationships between the
performance of the probe in SThM from one side and thermal conductivity,
geometry of the probe and its components from the other, providing pathway for
overcoming current limitations of SThM.

Mesoscale and Nanoscale Physics