Heat Transfer Between a Heated Microcantilever and the Substrate

This paper describes the heat transfer from a heated microcantilever to the substrate and the resultant temperature distributions. A four-point probe platinum resistive thermometer having a 140 nm lateral resolution has been fabricated on the SiO₂-coated silicon substrate. The estimated temperature coefficient of resistance (TCR) of the thermometer is 0.0011 K⁻¹, approximately one third of the bulk value. When the heated cantilever scans over the thermometer, up to 70% of the cantilever power is transferred to the substrate through the air, heating up the substrate. The maximum substrate temperature rise measured with the thermometer is around 7 K. From the force-displacement experiment, the effective contact thermal conductance was estimated to be around 40 ± 20 nW/K. The obtained results will help further understanding of thermal behavior of the heated cantilever during the scanning and its effect on the substrate.