Study on Sub-100-NM-Scale Measurement of Temperature Distribution in Joule-Heated Au Nanosheet Gas Sensors Using Self-Assembled Monolayers as Temperature Probes

We present a new method for temperature distribution measurement with sub-100-nm spatial resolution using molecular modification on device surfaces. In this method, a Au nanosheet modified with self-assembled monolayers (SAM) is locally heated by Joule heating. The SAM molecules are desorbed due to the local heating, and the temperature is estimated from the molecular distribution evaluated by Kelvin probe force microscopy (KFM). The validity of the temperature estimation is confirmed by finite-element-analysis (FEA) results. This method is useful for visualizing thermal distribution in nanoscale devices such as metal nanosheet gas sensors.