Scanning thermal-conductivity microscope

This article describes a novel implementation of an atomic force microscope that can map thermal-conductivity features across a sample with a high spatial resolution. The microscope employs a single-sided, metal-coated cantilever, which acts as a bimetallic strip together with a heating laser whose beam is focused on the cantilever's free end, on the opposite side of its tip. Subtracting the topography obtained by the unheated and heated cantilevers yields a map of thermal conductivity across the surface of a sample. The article presents (a) the theory of operation of the microscope and (b) the experimental results obtained on a silicon sample with oxide features, showing good agreement between the two.