Experimental investigation on the heat transfer between a heated microcantilever and a substrate

This work describes the heat transfer process from a heated microcantilever to a substrate. A platinum-resistance thermometer with a 140 nm width was fabricated on a SiO₂-coated silicon substrate. The temperature coefficient of resistance estimated from the measurement was 7 × 10^-4 K^-1, about one-fifth of the bulk value of platinum. The temperature distribution on the substrate was obtained from the thermometer reading, as the cantilever raster scanned the substrate. Comparison between the measurement and calculation reveals that up to 75% of the cantilever power is directly transferred to the substrate through the air gap. From the force-displacement experiment, the effective tip-specimen contact thermal conductance was estimated to be around 40 nW/K. The findings from this study should help understand the thermal interaction between the heated cantilever and the substrate, which is essential to many nanoscale technologies using heated cantilever.