Development of a quantitative nanoscale thermal conductivity profiling technique by the removal of influence due to heat transfer through the air

We developed a quantitative thermal property profiling technique that measures the thermal property of the sample from the tip-sample heat transfer only using SThM. The principle of the technique is explained rigorously through a theoretical analysis of the heat transfer phenomena. The spatial resolution of this technique was demonstrated by obtaining the thermal conductivity profile of samples in which a thin silicon oxide layer is sandwiched between single crystal silicon layers. For a sample with 1.4 μm thick silicon oxide layer, its thermal conductivity was quantitatively profiled. However, for a sample with 100 nm thick silicon oxide layer, the obtained profile was not quantitative. From the experimental results the quantitative spatial resolution of this technique is estimated to be around 200 nm. In order to further improve the quantitative spatial resolution of this technique, the tip radius of the completed thermocouple SThM probe should be reduced further.