Scanning thermal wave microscopy

This paper reports the development of a new technique for nanometer-scale thermal imaging and thermal property measurement - scanning thermal wave microscope (STWM). By raster scanning a sharp temperature-sensing probe the STWM measures the distribution of the phase lag and the amplitude of a thermal wave on the sample surface at a certain distance away from the heat source. As a benchmark experiment for this technique, the phase lag distribution of a thermal wave generated by a line heat source on a Pyrex glass sample was measured and compared with analytical solution. The effect of liquid film at the tip-sample contact on the measured phase lag was also studied. The ability of STWM to locate sub-surface heat source in a ULSI circuit was experimentally demonstrated.