Accurate New Methodology in Scanning Thermal Microscopy

In this study, we present a scanning thermal microscopy experiment with the probe working under vacuum allowing a spatial resolution of 25 nm. These measurements are made with a new four-contacts resistive probe, well suited for the 3ω measurement technique. A system identification approach in the out-of-contact mode provides the thermal model of the probe. This approach does not require knowledge of the geometrical and thermal properties of the probe. This sensor model is integrated into a comprehensive global model taking into account the heat transfer within the investigated surface. We show that the contact resistance and the radius of the contact area at the probe-material interface can be identified and are independent of the nature of the probed material when thermal conductivity ranges from 0.2 to 41 W · m^-1 · K^-1.