Scanning thermal imaging of an electrically excited aluminum microstripe

We study the Joule heating of a 1.25 μm wide aluminum microstripe excited by an electrical current. The temperature changes are measured with a scanning thermal microscope that uses a small fluorescent particle as a sensor. The lateral resolution observed for this sample is better than 300 nm. We have compared the temperature distribution in the stripe with a simple analytical model of heat propagation in the wire and the substrate. A good qualitative agreement is observed, although the measured temperature is much smaller than the estimated one, showing that the heat transfer between the hot wire and the fluorescent probe is not fully efficient.