SCANNING THERMAL MICROSCOPY (SThM)

There has been growing interest in the heat dispersion of nanostructured materials. Park AFM's Scanning Thermal Microscopy (SThM) mode was developed to probe thermal properties at the nanoscale level. SThM uses nanofabricated thermal probes with resistive elements to achieve unprecedented high spatial and thermal resolution and sensitivity with a unique signal detection scheme.

Figure 1 shows the schematic diagram of system behind SThM with Park AFM. A "V" shaped resistive element is mounted at the end of a cantilever. While the distance between the probe tip and sample surface is controlled by a usual AFM scheme, The thermal probe forms one leg of a Wheatstone bridge

Figure 2 (a) and (b) shows scanning electron microscopy (SEM) images of a typical Wollaston wire thermal probe and the nanofabricated thermal probe used in SThM with Park AFM. The tip radius of the nanofabricated probe is about 100 nm enabling high resolution thermal image scan while a Wollaston wire probe's tip radius is over several hundred nm.