Investigation of contact thermal resistance at the probe-sample interface in scanning thermal microscopy based on the fractal network model through numerical analysis

Abstract

Scanning Thermal Microscopy (SThM) enables precise thermal mapping at the nanoscale. Nevertheless, it is challenging to quantitatively determine material thermal properties since the heat conduction at the scanning probe-sample interface is difficult to be measured directly. The heat conduction in the micro-domain must be clarified to enable accurate quantitative testing of thermophysical properties via SThM. This study aims to investigate the contact situation at the probe-sample interface using fractal theory and proposes a numerical model for calculating the contact thermal resistance. To verify the model’s accuracy, various surface geometries are specially designed. Furthermore, the impact of the sample surface fractal characteristics on the test accuracy is discussed through localized thermal signal feedback analysis.